How memory works

How emotion keeps some memories vivid

September, 2012

Emotionally arousing images that are remembered more vividly were seen more vividly. This may be because the amygdala focuses visual attention rather than more cognitive attention on the image.

We know that emotion affects memory. We know that attention affects perception (see, e.g., Visual perception heightened by meditation training; How mindset can improve vision). Now a new study ties it all together. The study shows that emotionally arousing experiences affect how well we see them, and this in turn affects how vividly we later recall them.

The study used images of positively and negatively arousing scenes and neutral scenes, which were overlaid with varying amounts of “visual noise” (like the ‘snow’ we used to see on old televisions). College students were asked to rate the amount of noise on each picture, relative to a specific image they used as a standard. There were 25 pictures in each category, and three levels of noise (less than standard, equal to standard, and more than standard).

Different groups explored different parameters: color; gray-scale; less noise (10%, 15%, 20% as compared to 35%, 45%, 55%); single exposure (each picture was only presented once, at one of the noise levels).

Regardless of the actual amount of noise, emotionally arousing pictures were consistently rated as significantly less noisy than neutral pictures, indicating that people were seeing them more clearly. This was true in all conditions.

Eye-tracking analysis ruled out the idea that people directed their attention differently for emotionally arousing images, but did show that more eye fixations were associated both with less noisy images and emotionally arousing ones. In other words, people were viewing emotionally important images as if they were less noisy.

One group of 22 students were given a 45-minute spatial working memory task after seeing the images, and then asked to write down all the details they could remember about the pictures they remembered seeing. The amount of detail they recalled was taken to be an indirect measure of vividness.

A second group of 27 students were called back after a week for a recognition test. They were shown 36 new images mixed in with the original 75 images, and asked to rate them as new, familiar, or recollected. They were also asked to rate the vividness of their recollection.

Although, overall, emotionally arousing pictures were not more likely to be remembered than neutral pictures, both experiments found that pictures originally seen as more vivid (less noise) were remembered more vividly and in more detail.

Brain scans from 31 students revealed that the amygdala was more active when looking at images rated as vivid, and this in turn increased activity in the visual cortex and in the posterior insula (which integrates sensations from the body). This suggests that the increased perceptual vividness is not simply a visual phenomenon, but part of a wider sensory activation.

There was another neural response to perceptual vividness: activity in the dorsolateral prefrontal cortex and the posterior parietal cortex was negatively correlated with vividness. This suggests that emotion is not simply increasing our attentional focus, it is instead changing it by reducing effortful attentional and executive processes in favor of more perceptual ones. This, perhaps, gives emotional memories their different ‘flavor’ compared to more neutral memories.

These findings clearly need more exploration before we know exactly what they mean, but the main finding from the study is that the vividness with which we recall some emotional experiences is rooted in the vividness with which we originally perceived it.

The study highlights how emotion can sharpen our attention, building on previous findings that emotional events are more easily detected when visibility is difficult, or attentional demands are high. It is also not inconsistent with a study I reported on last year, which found some information needs no repetition to be remembered because the amygdala decrees it of importance.

I should add, however, that the perceptual effect is not the whole story — the current study found that, although perceptual vividness is part of the reason for memories that are vividly remembered, emotional importance makes its own, independent, contribution. This contribution may occur after the event.

It’s suggested that individual differences in these reactions to emotionally enhanced vividness may underlie an individual’s vulnerability to post-traumatic stress disorder.

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Second language processing differs for negative words

June, 2012

A study involving Chinese-English bilinguals shows how words with negative emotional connotations don’t automatically access native translations, while those with positive or neutral emotions do.

Here’s an intriguing study for those interested in how language affects how we think. It’s also of interest to those who speak more than one language or are interested in learning another language, because it deals with the long-debated question as to whether bilinguals working in their non-native language automatically access the native-language representations in long-term memory, or whether they can ‘switch off’ their native language and use only the target language memory codes.

The study follows on from an earlier study by the same researchers that indicated, through the demonstration of hidden priming effects, that bilinguals subconsciously access their first language when reading in their second language. In this new study, 45 university students (15 native English speakers, 15 native Chinese speakers, and 15 Chinese-English bilinguals) were shown two blocks of 90 word pairs. The pairs could have positive emotional value (e.g., honesty-program), negative valence (failure-poet), or neutral valence (aim-carpenter); could be semantically related (virus-bacteria; love-rose) or unrelated (weather-gender). The English or Chinese words were flashed on the screen one at a time, with a brief interval between the first and second word. The students had to indicate whether the second word was related in meaning to the first, and their brain activity was monitored.

The English and Chinese speakers acted as controls — it was the bilinguals, of course, who were the real interest. Some of the English word pairs shared a sound in the Chinese translation. If the Chinese words were automatically activated, therefore, the sound repetition would have a priming effect.

This is indeed what was found (confirming the earlier finding and supporting the idea that native language translations are automatically activated) — but here’s the interesting thing: the priming effect occurred only for positive and neutral words. It did not occur when the bilinguals saw negative words such as war, discomfort, inconvenience, and unfortunate.

The finding, which surprised the researchers, is nonetheless consistent with previous evidence that anger, swearing or discussing intimate feelings has more power in a speaker's native language. Parents, too, tend to speak to their infants in their native tongue. Emotion, it seems, is more strongly linked to our first language.

It’s traditionally thought that second language processing is fundamentally determined by the age of acquisition and the level of proficiency. The differences in emotional resonance have been, naturally enough, attributed to the native language being acquired first. This finding suggests the story is a little more complicated.

The researchers theorize that they have touched on the mechanism by which emotion controls our fundamental thought processes. They suggest that the brain is trying to protect us by minimizing the effect of distressing or disturbing emotional content, by shutting down the unconscious access to the native language (in which the negative words would be more strongly felt).

A few more technical details for those interested:

The Chinese controls demonstrated longer reaction times than the English controls, which suggests (given that 60% of the Chinese word pairs had overt sound repetitions but no semantic relatedness) that this conjunction made the task substantially more difficult. The bilinguals, however, had reaction times comparable to the English controls. The Chinese controls showed no effect of emotional valence, but did show priming effects of the overt sound manipulation that were equal for all emotion conditions.

The native Chinese speakers had recently arrived in Britain to attend an English course. Bilinguals had been exposed to English since the age of 12 and had lived in Britain for an average of 20.5 months.

Reference: 

[2969] Wu, Y J., & Thierry G.
(2012).  How Reading in a Second Language Protects Your Heart.
The Journal of Neuroscience. 32(19), 6485 - 6489.

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Walking through doorways causes forgetting

March, 2012

A series of experiments indicates that walking through doorways creates event boundaries, requiring us to update our awareness of current events and making information about the previous location less available.

We’re all familiar with the experience of going to another room and forgetting why we’ve done so. The problem has been largely attributed to a failure of attention, but recent research suggests something rather more specific is going on.

In a previous study, a virtual environment was used to explore what happens when people move through several rooms. The virtual environment was displayed on a very large (66 inch) screen to provide a more immersive experience. Each ‘room’ had one or two tables. Participants ‘carried’ an object, which they would deposit on a table, before picking up a different object. At various points, they were asked if the object was, say, a red cube (memory probe). The objects were not visible at the time of questioning. It was found that people were slower and less accurate if they had just moved to a new room.

To assess whether this effect depends on a high degree of immersion, a recent follow-up to this study replicated the study using standard 17” monitors rather than the giant screens. The experiment involved 55 students and once again demonstrated a significant effect of shifting rooms. Specifically, when the probe was positive, the error rate was 19% in the shift condition compared to 12% on trials when the participant ‘traveled’ the same distance but didn’t change rooms. When the probe was negative, the error rate was 22% in the shift condition vs 7% for the non-shift condition. Reaction time was less affected — there was no difference when the probes were positive, but a marginally significant difference on negative-probe trials.

The second experiment went to the other extreme. Rather than reducing the immersive experience, researchers increased it — to a real-world environment. Unlike the virtual environments, distances couldn’t be kept constant across conditions. Three large rooms were used, and no-shift trials involved different tables at opposite ends of the room. Six objects, rather than just one, were moved on each trial. Sixty students participated.

Once again, more errors occurred when a room-shift was involved. On positive-probe trials, the error rate was 28% in the shift condition vs 23% in the non-shift. On negative-probe trials, the error rate was 21% and 18%, respectively. The difference in reaction times wasn’t significant.

The third experiment, involving 48 students, tested the idea that forgetting might be due to the difference in context at retrieval compared to encoding. To do this, the researchers went back to using the more immersive virtual environment (the 66” screen), and included a third condition. In this, either the participant returned to the original room to be tested (return) or continued on to a new room to be tested (double-shift) — the idea being to hold the number of spatial shifts the same.

There was no evidence that returning to the original room produced the sort of advantage expected if context-matching was the important variable. Memory was best in the no-shift condition, next best in the shift and return conditions (no difference between them), and worst in the double shift condition. In other words, it was the number of new rooms entered that appears to be important.

This is in keeping with the idea that we break the action stream into separate events using event boundaries. Passing through a doorway is one type of event boundary. A more obvious type is the completion of an action sequence (e.g., mixing a cake — the boundary is the action of putting it in the oven; speaking on the phone — the boundary is the action of ending the call). Information being processed during an event is more available, foregrounded in your attention. Interference occurs when two or more events are activated, increasing errors and sometimes slowing retrieval.

All of this has greater ramifications than simply helping to explain why we so often go to another room and forget why we’re there. The broader point is that everything that happens to us is broken up and filed, and we should look for the boundaries to these events and be aware of the consequences of them for our memory. Moreover, these contextual factors are important elements of our filing system, and we can use that knowledge to construct more effective tags.

Read an article on this topic at Mempowered

Reference: 

[2660] Radvansky, G. A., Krawietz S. A., & Tamplin A. K.
(2011).  Walking Through Doorways Causes Forgetting: Further Explorations.
The Quarterly Journal of Experimental Psychology.

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Genes

Older news items (pre-2010) brought over from the old website

‘Memory gene’ impacts driving performance

People with a particular variant (“met”) of the COMT gene performed more than 20% worse on a driving test than people without it. About 30% of Americans have the variant, which limits the availability of the vital protein BDNF during activity. Previous studies have shown that in people with the variant, episodic (event) memory is poorer, and a smaller portion of the brain is stimulated when doing a task. The study involved 29 people, of whom 7 had the gene variant, driving 15 laps on a simulator that required them to learn the nuances of a track programmed to have difficult curves and turns. The test was repeated 4 days later. Those with the variant did worse on both tests than the other participants, and they remembered less the second time. However, the gene isn’t all bad — although carriers don't recover as well after a stroke, they retain their mental sharpness longer in the case of neurodegenerative disease.

[1283] McHughen, S. A., Rodriguez P. F., Kleim J. A., Kleim E. D., Crespo L M., Procaccio V., et al.
(2010).  BDNF Val66Met Polymorphism Influences Motor System Function in the Human Brain.
Cereb. Cortex. 20(5), 1254 - 1262.

http://www.sciencedaily.com/releases/2009/10/091028134637.htm
http://www.miller-mccune.com/news/are-you-a-bad-driver-it-may-not-be-your-fault-1577
http://www.eurekalert.org/pub_releases/2009-10/uoc--bdm102809.php

Two studies help explain the spacing effect

I talked about the spacing effect in my last newsletter. Now it seems we can point to the neurology that produces it. Not only that, but the study has found a way of modifying it, to improve learning. It’s a protein called SHP-2 phosphatase that controls the spacing effect by determining how long resting intervals between learning sessions need to last so that long-lasting memories can form. The discovery happened because more than 50% of those with a learning disorder called Noonan's disease have mutations in a gene called PTP11, which encodes the SHP-2 phosphatase protein. These mutations boost the activity levels of SHP-2 phosphatase, which, in genetically modified fruit flies, disturbs the spacing effect by increasing the interval before a new chemical signal can occur (it is the repeated formation and decay of these signals that produces memory). Accordingly, those with the mutation need longer periods between repetitions to establish long-term memory.

[1433] Pagani, M. R., Oishi K., Gelb B. D., & Zhong Y.
(2009).  The Phosphatase SHP2 Regulates the Spacing Effect for Long-Term Memory Induction.
Cell. 139(1), 186 - 198.

http://www.eurekalert.org/pub_releases/2009-10/cshl-csi092809.php

A study involving Aplysia (often used as a model for learning because of its simplicity and the large size of its neural connections) reveals that spaced and massed training lead to different types of memory formation. The changes at the synapses that underlie learning are controlled by the release of the neurotransmitter serotonin. Four to five spaced applications of serotonin generated long-term changes in the strength of the synapse and less activation of the enzyme Protein kinase C Apl II, leading to stronger connections between neurons. However, when the application of serotonin was continuous (as in massed learning), there was much more activation of PKC Apl II, suggesting that activation of this enzyme may block the mechanisms for generating long-term memory, while retaining mechanisms for short-term memory.

[1504] Villareal, G., Li Q., Cai D., Fink A. E., Lim T., Bougie J. K., et al.
(2009).  Role of Protein Kinase C in the Induction and Maintenance of Serotonin-Dependent Enhancement of the Glutamate Response in Isolated Siphon Motor Neurons of Aplysia californica.
J. Neurosci.. 29(16), 5100 - 5107.

http://www.eurekalert.org/pub_releases/2009-10/mu-wow100109.php

Smart gene helps brain cells communicate

For the second time, scientists have created a smarter rat by making their brains over-express CaMKII, a protein that acts as a promoter and signaling molecule for the NR2B subunit of the NMDA receptor. Over-expressing the gene lets brain cells communicate a fraction of a second longer. The research indicates that it plays a crucial role in initiating long-term potentiation. The NR2B subunit is more common in juvenile brains; after puberty the NR2A becomes more common. This is one reason why young people tend to learn and remember better — because the NR2B keeps communication between brain cells open maybe just a hundred milliseconds longer than the NR2A. Although this genetic modification is not something that could probably be replicated in humans, it does validate NR2B as a drug target for improving memory in healthy individuals as well as those struggling with Alzheimer's or mild dementia.

[599] Wang, D., Cui Z., Zeng Q., Kuang H., Wang P. L., Tsien J. Z., et al.
(2009).  Genetic Enhancement of Memory and Long-Term Potentiation but Not CA1 Long-Term Depression in NR2B Transgenic Rats.
PLoS ONE. 4(10), e7486 - e7486.

Full text at http://dx.plos.org/10.1371/journal.pone.0007486

http://www.eurekalert.org/pub_releases/2009-10/mcog-sr101909.php

Common variation in gene linked to structural changes in the brain

Variations in the regions of the gene MECP2, previously associated with Retts Syndrome, autism, and mental retardation, has been found to be associated with changes in brain structure in both healthy individuals and patients with neurological and psychiatric disorders. The study used data from 289 healthy and psychotic subjects (the TOP study), and 655 healthy and demented patients (mostly Alzheimer's; from the ADNI study). The most significant genetic variation resulted in reduced surface area in the cortex (in particular in the cuneus, fusiform gyrus, pars triangularis), and was specific to males.

[297] Schork, N. J., Andreassen O. A., Dale A. M., Joyner A. H., Roddey J. Cooper, Bloss C. S., et al.
(2009).  A common MECP2 haplotype associates with reduced cortical surface area in humans in two independent populations.
Proceedings of the National Academy of Sciences. 106(36), 15483 - 15488.

http://www.eurekalert.org/pub_releases/2009-08/uoc--cvi081709.php
http://www.eurekalert.org/pub_releases/2009-08/sri-sru081809.php

Genes more important for IQ as children get older

Data from six studies carried out in the US, the UK, Australia and the Netherlands, involving a total of 11,000 pairs of twins, has revealed that genes become more important for intelligence as we get older. The researchers calculated that genes accounted for some 41% of the variation in intelligence in 9 year olds, rising to 55% in 12 year olds, and 66% in 17 year olds. It was suggested that as they get older, children get better at controlling (or perhaps are allowed to have more control over) their environment, which they do in a way that accentuates their ‘natural’ abilities — bright children feed their abilities; less bright children choose activities and friends that are less challenging.

Haworth, C.M.A. et al. 2009. R Plomin The heritability of general cognitive ability increases linearly from childhood to young adulthood. Molecular Psychiatry, advance online publication 2 June 2009; doi: 10.1038/mp.2009.55

http://www.newscientist.com/article/mg20327174.600-genes-drive-iq-more-as-kids-get-older.html

Early maternal experience can affect memory in her offspring

A study of pre-adolescent mice with a genetically-created defect in memory has found that a mere two weeks exposure to a stimulating environment resulted in a reversal of the memory defect. But most surprisingly, it was also found that this effect was passed on to the next generation, even though they had the same genetic defect and even though they had no such experience themselves, and even when they were reared by other mice (not their mothers). It’s worth emphasizing that the enrichment occurs for the mother long before she’s fertile, yet still benefits her offspring. The finding adds to many recent studies showing that genes are more malleable than we thought.

[1434] Arai, J. A., Li S., Hartley D. M., & Feig L. A.
(2009).  Transgenerational Rescue of a Genetic Defect in Long-Term Potentiation and Memory Formation by Juvenile Enrichment.
J. Neurosci.. 29(5), 1496 - 1502.

http://www.physorg.com/news152905156.html
http://www.eurekalert.org/pub_releases/2009-02/rumc-wym020209.php
http://www.eurekalert.org/pub_releases/2009-02/tuhs-dyk012909.php

A gene that influences intelligence

A study involving more than 2000 people from 200 families has found a link between the gene CHRM2, that activates multiple signaling pathways in the brain involved in learning, memory and other higher brain functions, and performance IQ. Researchers found that several variations within the CHRM2 gene (which is on chromosome 7) could be correlated with slight differences in performance IQ scores, which measure a person's visual-motor coordination, logical and sequential reasoning, spatial perception and abstract problem solving skills, and when people had more than one positive variation in the gene, the improvements in performance IQ were cumulative. Intelligence is a complex attribute that results from a combination of many genetic and environmental factors, so don’t interpret this finding to mean we’ve found a gene for intelligence.

[1173] Edenberg, H., Porjesz B., Begleiter H., Hesselbrock V., Goate A., Bierut L., et al.
(2007).  Association of CHRM2 with IQ: Converging Evidence for a Gene Influencing Intelligence.
Behavior Genetics. 37(2), 265 - 272.

http://www.eurekalert.org/pub_releases/2007-02/wuso-gag022607.php

Common gene version optimizes thinking but carries a risk

On the same subject, another study has found that the most common version of DARPP-32, a gene that shapes and controls a circuit between the striatum and prefrontal cortex, optimizes information filtering by the prefrontal cortex, thus improving working memory capacity and executive control (and thus, intelligence). However, the same version was also more prevalent among people who developed schizophrenia, suggesting that a beneficial gene variant may translate into a disadvantage if the prefrontal cortex is impaired. In other words, one of the things that make humans more intelligent as a species may also make us more vulnerable to schizophrenia.

[864] Kolachana, B., Kleinman J. E., Weinberger D. R., Meyer-Lindenberg A., Straub R. E., Lipska B. K., et al.
(2007).  Genetic evidence implicating DARPP-32 in human frontostriatal structure, function, and cognition.
Journal of Clinical Investigation. 117(3), 672 - 682.

http://www.sciencedaily.com/releases/2007/02/070208230059.htm
http://www.eurekalert.org/pub_releases/2007-02/niom-cgv020707.php

Genetic cause for word-finding disease

Primary Progressive Aphasia is a little-known form of dementia in which people lose the ability to express themselves and understand speech. People can begin to show symptoms of PPA as early as in their 40's and 50's. A new study has found has discovered a gene mutation in two unrelated families in which nearly all the siblings suffered from PPA. The mutations were not observed in the healthy siblings or in more than 200 controls.

[1164] Hutton, M. L., Graff-Radford N. R., Mesulam M. Marsel, Johnson N., Krefft T. A., Gass J. M., et al.
(2007).  Progranulin Mutations in Primary Progressive Aphasia: The PPA1 and PPA3 Families.
Arch Neurol. 64(1), 43 - 47.

http://www.eurekalert.org/pub_releases/2007-01/nu-rdg011507.php

Longevity gene also helps retain cognitive function

The Longevity Genes Project has studied 158 people of Ashkenazi, or Eastern European Jewish, descent who were 95 years of age or older. Those who passed a common test of mental function were two to three times more likely to have a common variant of a gene associated with longevity (the CETP gene) than those who did not. When the researchers studied another 124 Ashkenazi Jews between 75 and 85 years of age, those subjects who passed the test of mental function were five times more likely to have this gene variant than their counterparts. The gene variant makes cholesterol particles in the blood larger than normal.

[916] Barzilai, N., Atzmon G., Derby C. A., Bauman J. M., & Lipton R. B.
(2006).  A genotype of exceptional longevity is associated with preservation of cognitive function.
Neurology. 67(12), 2170 - 2175.

http://tinyurl.com/yrf5s4
http://www.eurekalert.org/pub_releases/2006-12/aaon-lga121906.php

'Memory gene' identified

Analysis of the human genome has revealed a gene associated with memory performance. The gene is called Kibra, and is expressed in the hippocampus. According to brain scans, people with the version of the gene related to poorer memory potential had to tax their brains harder to remember the same amount of information.

[2658] Papassotiropoulos, A., Stephan D. A., Huentelman M. J., Hoerndli F. J., Craig D. W., Pearson J. V., et al.
(2006).  Common Kibra Alleles Are Associated with Human Memory Performance.
Science. 314(5798), 475 - 478.

http://www.eurekalert.org/pub_releases/2006-10/ttgr-rti101906.php

Protein found to inhibit conversion to long-term memory

In a study using genetically engineered mice, researchers have found that mice without a protein called GCN2 acquire new information that doesn’t fade as easily as it does in normal mice. After weak training on the Morris water maze, their spatial memory was enhanced, but it was impaired after more intense training. The researchers concluded that GCN2 may prevent new information from being stored in long-term memory, suggesting the conversion of new information into long-term memory requires both the activation of molecules that facilitate memory storage, and the silencing of proteins such as GCN2 that inhibit memory storage.

[949] Yoshida, M., Imataka H., Cuello C. A., Seidah N., Sossin W., Lacaille J-C., et al.
(2005).  Translational control of hippocampal synaptic plasticity and memory by the eIF2[alpha] kinase GCN2.
Nature. 436(7054), 1166 - 1173.

http://www.eurekalert.org/pub_releases/2005-08/uom-mrp082905.php

Closing in on the genes involved in human intelligence

A genetic study claims to have identified two regions of the human genome that appear to explain variation in IQ. Previous research has suggested that between 40% and 80% of variation in human intelligence (as measured by IQ tests) can be attributed to genetic factors, but research has so far failed to identify these genes. The new study has identified specific locations on Chromosomes 2 and 6 as being highly influential in determining IQ, using data from 634 sibling pairs. The region on Chromosome 2 that shows significant links to performance IQ overlaps a region associated with autism. The region on Chromosome 6 that showed strong links with both full-scale and verbal IQ marginally overlapped a region implicated in reading disability and dyslexia.

[382] Posthuma, D., Luciano M., Geus E., Wright M., Slagboom P., Montgomery G., et al.
(2005).  A Genomewide Scan for Intelligence Identifies Quantitative Trait Loci on 2q and 6p.
The American Journal of Human Genetics. 77(2), 318 - 326.

http://www.qimr.edu.au/news/index.html

Human cerebellum and cortex age in very different ways

Analysis of gene expression in five different regions of the brain's cortex has found that brain changes with aging were pronounced and consistent across the cortex, but changes in gene expression in the cerebellum were smaller and less coordinated. Researchers were surprised both by the homogeneity of aging within the cortex and by the dramatic differences between cortex and cerebellum. They also found that chimpanzees' brains age very differently from human brains; the findings cast doubt on the effectiveness of using rodents to model various types of neurodegenerative disease.

[951] Fraser, H. B., Khaitovich P., Plotkin J. B., Pääbo S., & Eisen M. B.
(2005).  Aging and Gene Expression in the Primate Brain.
PLoS Biol. 3(9), e274 - e274.

http://www.eurekalert.org/pub_releases/2005-08/hu-hca072805.php

More light on a common developmental disorder

Chromosome 22q11.2 deletion syndrome is the most common genetic deletion syndrome, and causes symptoms such as heart defects, cleft palate, abnormal immune responses and cognitive impairments. Two related studies have recently cast more light on these cognitive impairments. Previously it was known that numerical abilities were impaired more than verbal skills. The new study found children with the chromosome deletion performed more poorly on experiments designed to test visual attention orienting, enumerating, and judging numerical magnitudes. All three tasks relate to how the children mentally represent objects and the spatial relationships among them, supporting previous arguments that such visual-spatial skills are a fundamental foundation to the later learning of counting and mathematics. The second study found that such children had changes in the shape, size and position of the corpus callosum, the main bridge between the two hemispheres.

[1139] Simon, T. J., Bearden C. E., Mc-Ginn D MD., & Zackai E.
(2005).  Visuospatial and Numerical Cognitive Deficits in Children with Chromosome 22Q11.2 Deletion Syndrome.
Cortex. 41(2), 145 - 155.

[812] Simon, T. J., Ding L., Bish J. P., McDonald-McGinn D. M., Zackai E. H., & Gee J.
(2005).  Volumetric, connective, and morphologic changes in the brains of children with chromosome 22q11.2 deletion syndrome: an integrative study.
NeuroImage. 25(1), 169 - 180.

http://www.eurekalert.org/pub_releases/2005-03/chop-lbt030205.php

Closing in on the genes involved in context learning

A study involving the worm C. elegans (whose genome has been completely sequenced) has demonstrated that even such simple animals demonstrate memory that is sensitive to context. In the study, the worms were trained in a salt medium to associate a particular smell with starvation. When placed in a different salt medium, the worms didn’t respond to the smell, but showed distaste when experiencing the smell in the context of the salt medium in which they were trained. More importantly, use of this animal has enabled the researchers to identify a genetic mutation that affects this type of memory. The next step will be to identify the specific gene involved in processing environmental cues.

[1072] Law, E., Nuttley W. M., & van der Kooy D.
(2004).  Contextual Taste Cues Modulate Olfactory Learning in C. elegans by an Occasion-Setting Mechanism.
Current Biology. 14(14), 1303 - 1308.

http://www.eurekalert.org/pub_releases/2004-07/uot-eil072704.php

Some brains age more rapidly than others

Investigation of the patterns of gene expression in post-mortem brain tissue has revealed two groups of genes with significantly altered expression levels in the brains of older individuals. The most significantly affected were mostly those related to learning and memory. One of the most interesting, and potentially useful, findings, is that patterns of gene expression were quite similar in the brains of younger adults. Very old adults also showed similar patterns, although the similarity was less. But the greatest degree of individual variation occurred in those aged between 40 and 70. Some of these adults showed gene patterns that looked more like the young group, whereas others showed gene patterns that looked more like the old group. It appears that gene changes start around 40 in some people, but not in others. It also appears that those genes that are affected by age are unusually vulnerable to damage from agents such as free radicals and toxins in the environment, suggesting that lifestyle in young adults may play a part in deciding rate and degree of cognitive decline in later years.

[1335] Lu, T., Pan Y., Kao S-Y., Li C., Kohane I., Chan J., et al.
(2004).  Gene regulation and DNA damage in the ageing human brain.
Nature. 429(6994), 883 - 891.

http://www.eurekalert.org/pub_releases/2004-06/chb-dgi060204.php

Could memory performance and spatial learning be genetically based?

A new rat study provides evidence that individual differences in some cognitive functions (specifically spatial navigation, in this experiment) may have a genetic basis.

[1267] Ruiz-Opazo, N., & Tonkiss J.
(2004).  X-linked loci influence spatial navigation performance in Dahl rats.
Physiological Genomics. 16(3), 329 - 333.

http://www.eurekalert.org/pub_releases/2004-02/aps-cmp020404.php

Gene essential for development of normal brain connections discovered

After birth, learning and experience change the architecture of the brain dramatically. The structure of individual neurons, or nerve cells, changes during learning to accommodate new connections between neurons. Neuroscientists believe these structural changes are initiated when neurons are activated, causing calcium ions to flow into cells and alter the activity of genes. Now the first gene, CREST, known to mediate these changes in the structure of neurons in response to calcium, has been discovered. In the study, it was found that mice lacking this gene didn’t develop normally in response to sensory experience, and their brains, while normal at birth, later showed far less interconnectivity between neurons. The gene produces a protein that, in adult humans, is produced in the hippocampus. It is therefore speculated that the protein may be necessary for learning and memory storage. The discovery of this gene may have implications for certain types of learning disorders in humans.

[915] Aizawa, H., Hu S-C., Bobb K., Balakrishnan K., Ince G., Gurevich I., et al.
(2004).  Dendrite development regulated by CREST, a calcium-regulated transcriptional activator.
Science (New York, N.Y.). 303(5655), 197 - 202.

http://www.eurekalert.org/pub_releases/2004-01/uoc--gef010804.php

Brain protein affecting learning and memory discovered

A significant new brain protein has been identified. Cypin is found throughout the body, but in the brain it now appears that it regulates neuron branching in the hippocampus. Such branching is thought to increase when learning occurs, and a reduction in branching is associated with certain neurological diseases. Discovery of this protein opens the possibility of new drug therapies for treating neurological disorders, and perhaps even memory-enhancing drugs.

[696] Akum, B. F., Chen M., Gunderson S. I., Riefler G. M., Scerri-Hansen M. M., & Firestein B. L.
(2004).  Cypin regulates dendrite patterning in hippocampal neurons by promoting microtubule assembly.
Nat Neurosci. 7(2), 145 - 152.

http://www.eurekalert.org/pub_releases/2004-01/rtsu-rsd011204.php
http://news.independent.co.uk/world/science_medical/story.jsp?story=482567

Amphetamine helps or hinders cognitive function depending on your genes

Everyone inherits two copies of the catecho-O-methyltransferase (COMT) gene, that codes for the enzyme that metabolizes neurotransmitters like dopamine and norepinephrine. It comes in two common versions. One version, met, contains the amino acid methionine at a point in its chemical sequence where the other version, val, contains a valine. Depending on the mix of variants inherited, a person's COMT genes can be typed met/met, val/val, or val/met. People with the val/val variant appear to have reduced prefrontal dopamine activity and less efficient prefrontal information processing, along with slightly increased risk for schizophrenia. People with val/met have more efficient prefrontal function, and people with met/met the most efficient.
In a recent imaging study, 27 volunteers (10 val/val, 11 val/met, and 6 met/met) performed a variety of cognitive tasks that involved working memory and executive functioning, after taking either amphetamine or a placebo. Since amphetamine boosts dopamine activity in the prefrontal cortex, the researchers predicted that the drug would enable val/val types to boost their low level of dopamine and perform better on cognitive tasks that depend on the prefrontal cortex. On the other hand, those with met/met should be hindered by amphetamine. The study confirmed these predictions - val/val subjects on amphetamine performed comparably to met/met types in normal conditions, while met/met subjects on amphetamine performed worse than subjects with val/val types in normal conditions.
Amphetamines and other drugs that affect prefrontal dopamine systems are used to treat Attention Deficit Hyperactivity Disorder (ADHD), and other psychiatric illnesses, and some people respond better than others to these medications. About 15-20% of individuals in populations of European ancestry have the met/met COMT gene type.

[1292] Mattay, V. S., Goldberg T. E., Fera F., Hariri A. R., Tessitore A., Egan M. F., et al.
(2003).  Catechol O-methyltransferase val158-met genotype and individual variation in the brain response to amphetamine.
Proceedings of the National Academy of Sciences of the United States of America. 100(10), 6186 - 6191.

http://www.eurekalert.org/pub_releases/2003-05/niom-gep050703.php

Gene linked to poor episodic memory

Brain derived neurotrophic factor (BDNF) plays a key role in neuron growth and survival and, it now appears, memory. We inherit two copies of the BDNF gene - one from each parent - in either of two versions. Slightly more than a third inherit at least one copy of a version nicknamed "met," which the researchers have now linked to poorer memory. Those who inherit the “met” gene appear significantly worse at remembering events that have happened to them, probably as a result of the gene’s effect on hippocampal function. Most notably, those who had two copies of the “met” gene scored only 40% on a test of episodic (event) memory, while those who had two copies of the other version scored 70%. Other types of memory did not appear to be affected. It is speculated that having the “met” gene might also increase the risk of disorders such as Alzheimer’s and Parkinson's.

[1039] Dean, M., Egan M. F., Kojima M., Callicott J. H., Goldberg T. E., Kolachana B. S., et al.
(2003).  The BDNF val66met Polymorphism Affects Activity-Dependent Secretion of BDNF and Human Memory and Hippocampal Function.
Cell. 112(2), 257 - 269.

http://www.nih.gov/news/pr/jan2003/nimh-23.htm
http://www.eurekalert.org/pub_releases/2003-01/niom-hga012203.php
http://news.bbc.co.uk/1/hi/health/2687267.stm

tags memworks: 

Gender

Older news items (pre-2010) brought over from the old website

Gender gap in math is culture-based

Data from the Trends in International Mathematics and Science Study and the Programme for International Student Assessment, representing 493,495 students ages 14-16 from 69 countries, have revealed only very small gender differences overall, but marked variation when nations are compared. For example, there are more girls in the top tier in countries such as Iceland, Thailand, and the United Kingdom–and even in certain U.S. populations, such as Asian-Americans. However, despite overall similarities in math skills, boys felt significantly more confident in their abilities than girls did and were more motivated to do well. Furthermore, although some studies have found more males than females scoring above the 95th or 99th percentile, this gender gap has significantly narrowed over time in the U.S. and is not found among some ethnic groups and in some nations. Greater male variability with respect to mathematics, where it exists, correlates with several measures of gender inequality.

[707] Hyde, J S., & Mertz J. E.
(2009).  Gender, culture, and mathematics performance.
Proceedings of the National Academy of Sciences. 106(22), 8801 - 8807.

Else-Quest, N.M., Hyde, J.S. & Linn, M.C. 2010. Cross-national patterns of gender differences in mathematics: A meta-analysis. Psychological Bulletin, 136(1), 103-127.

http://spectrum.ieee.org/at-work/education/math-quiz-why-do-men-predominate 

http://www.physorg.com/news181915640.html

Positive stereotypes can offset negative stereotype effect

A number of studies have now shown that negative stereotypes can impair cognitive performance, mainly through adding to working memory load. A new study has now shown that this effect can be mitigated by the activation of a positive stereotype. The research takes advantage of the fact that we all belong to several social groups. In this case, the relevant groups were ‘female’ and ‘college student’. As usual, when (subtly) reminded of negative stereotypes for women and math, women performed worse. The interesting thing was that this didn’t happen if women were also made aware that college students performed better at math than non-college students. Moreover, this was reflected in working memory capacity. It seems that, when both a positive and a negative stereotype are offered, people will tend to choose the positive stereotype, and the effects of this will cancel out the negative stereotype. It’s also worth noting how easily these stereotypes are activated: effects could be manipulated simply by subtly changing demographic questions asked before the test (and it is not uncommon that test-takers are first required to answer some demographic questions).

[1381] Rydell, R. J., McConnell A. R., & Beilock S. L.
(2009).  Multiple social identities and stereotype threat: Imbalance, accessibility, and working memory..
Journal of Personality and Social Psychology. 96(5), 949 - 966.

http://www.eurekalert.org/pub_releases/2009-05/iu-pob050109.php

Sex difference on spatial skill test linked to brain structure

It’s been well established that men (as a group) consistently out-perform women on spatial tasks. Research has also established that the parietal lobes in women tend to have proportionally more gray matter. Now a new study shows that the thicker cortex in the parietal lobe in women is associated with poorer mental rotation ability. It also reveals that the surface area of the parietal lobe is increased in men, compared to women, and this is directly related to better performance on mental rotation tasks. It also appears that, perhaps because the brain structure is different between men and women, the way the brain performs the task is different. While men appear able to globally rotate an object in space, women seem to do it piecemeal.

[1159] Koscik, T., O'Leary D., Moser D. J., Andreasen N. C., & Nopoulos P.
(2009).  Sex differences in parietal lobe morphology: Relationship to mental rotation performance.
Brain and Cognition. 69(3), 451 - 459.

http://www.physorg.com/news148740976.html

Gender gap in spatial skills starts in infancy

On their own, the findings reported above do not answer the question of whether gender differences in spatial ability are biological or cultural, as differences in brain structure and performance can be caused by different experiences during childhood. However, research has repeatedly found a gender difference in mental rotation in children four years and older, and now a new study has found evidence that male superiority in mental rotation is present in infants as young as 5 months old.

[703] Moore, D. S., & Johnson S. P.
(2008).  Mental rotation in human infants: a sex difference.
Psychological Science: A Journal of the American Psychological Society / APS. 19(11), 1063 - 1066.

http://www.physorg.com/news148046936.html

Gender differences in memory

A series of experiments looking at memory performance in men and women has revealed that women did better at verbal episodic memory tasks, such as remembering words, objects, pictures or everyday events, and men outperformed women in remembering symbolic, non-linguistic information, known as visuospatial processing. But women were again better on tasks that require both verbal and visuospatial processing, such as remembering the location of car keys. Women were also better at remembering faces, especially female faces. They also remembered androgynous faces presented as female more accurately than the androgynous faces presented as male, suggesting the reason is that women pay more attention to female than to male faces. Women also performed better than men in tasks requiring little to no verbal processing, such as recognition of familiar odors. But environmental factors, such as education, seem to influence the magnitude of these sex differences.

[1078] Herlitz, A., & Rehnman J.
(2008).  Sex Differences in Episodic Memory.
Current Directions in Psychological Science. 17(1), 52 - 56.

http://www.eurekalert.org/pub_releases/2008-02/afps-tgr022008.php

Review supports mild memory impairment in pregnancy

A review of 14 studies testing the memory performances of more than 1,000 pregnant women, mothers and non-pregnant women, has found that pregnant women performed significantly worse on some, but not all aspects of the test. The hardest tests for the pregnant women were those that involved new or demanding tasks. Regular, well-practiced memory tasks were unlikely to be affected. The impairment wasn’t large — comparable to the modest deficits you'd find when comparing healthy 20-year-olds with healthy 60-year-olds. However, the impairment was sometimes still evident a year after birth (none looked beyond that point).

[876] Henry, J. D., & Rendell P. G.
(2007).  A review of the impact of pregnancy on memory function.
Journal of Clinical and Experimental Neuropsychology. 29(8), 793 - 793.

http://www.physorg.com/news121413361.html

Stereotype-induced math anxiety robs women's working memory

Another study finds evidence that being told men are better at mathematics undermines women's math performance, and extends it by demonstrating that the anxiety induced by the stereotype mainly reduced the verbal part of working memory, and that this carried over to subsequent (non-math-related) tasks. The accuracy of women exposed to the stereotype was reduced from nearly 90% in a pretest to about 80% after being told men do better in mathematics. Among women not receiving that message, performance actually improved slightly.

[505] Beilock, S. L., Rydell R. J., & McConnell A. R.
(2007).  Stereotype Threat and Working Memory: Mechanisms, Alleviation, and Spillover.
Journal of Experimental Psychology: General. 136(2), 256 - 276.

http://www.physorg.com/news99239898.html
http://www.eurekalert.org/pub_releases/2007-05/uoc-sma052107.php

Gender differences in the brain

Results from an extremely large internet survey looking at sex-linked cognitive abilities, personality traits, interests, sexual attitudes and behavior, as well as physical traits, has found that cognitive abilities decline with age more steeply in men than in women. This effect is independent of sexual orientation. Differences in specific cognitive abilities were also found that did depend on sexual orientation as well as gender. Men scored higher than women on tests of mental rotation and the ability to judge line angles, whereas women scored higher than men on tests of object location memory and word fluency. However, homosexual men's visual-spatial abilities were, on average, lower than those of heterosexual men, and lesbian women's visual-spatial abilities were higher than those of heterosexual women.

[1181] Maylor, E. A., Reimers S., Choi J., Collaer M. L., Peters M., & Silverman I.
(2007).  Gender and sexual orientation differences in cognition across adulthood: age is kinder to women than to men regardless of sexual orientation.
Archives of Sexual Behavior. 36(2), 235 - 249.

[945] Collaer, M. L., Reimers S., & Manning J. T.
(2007).  Visuospatial performance on an internet line judgment task and potential hormonal markers: sex, sexual orientation, and 2D:4D.
Archives of Sexual Behavior. 36(2), 177 - 192.

[905] Peters, M., Manning J., & Reimers S.
(2007).  The Effects of Sex, Sexual Orientation, and Digit Ratio (2D:4D) on Mental Rotation Performance.
Archives of Sexual Behavior. 36(2), 251 - 260.

http://www.sciencedaily.com/releases/2007/05/070507113352.htm

Sex and prenatal hormones affect cognitive performance

A study involving rhesus macaque monkeys has found that the tendency to use landmarks for navigation is typical only of females. In a situation where they had to navigate an open area to locate highly valued food items in goal boxes, gender or prenatal treatment did not affect how well the monkeys did when both spatial and marker cues were available. When landmarks directly indicated the correct locations but spatial information was unreliable, females performed better than males. Moreover, males whose testosterone exposure had been blocked early in gestation were more able to use the landmarks to navigate than normal males.

[1186] Herman, R. A., & Wallen K.
(2007).  Cognitive performance in rhesus monkeys varies by sex and prenatal androgen exposure.
Hormones and Behavior. 51(4), 496 - 507.

http://www.sciencedaily.com/releases/2007/04/070413102051.htm
http://www.eurekalert.org/pub_releases/2007-04/eu-sap041207.php

Implicit stereotypes and gender identification may affect female math performance

Relatedly, another study has come out showing that women enrolled in an introductory calculus course who possessed strong implicit gender stereotypes, (for example, automatically associating "male" more than "female" with math ability and math professions) and were likely to identify themselves as feminine, performed worse relative to their female counterparts who did not possess such stereotypes and who were less likely to identify with traditionally female characteristics. Strikingly, a majority of the women participating in the study explicitly expressed disagreement with the idea that men have superior math ability, suggesting that even when consciously disavowing stereotypes, female math students are still susceptible to negative perceptions of their ability.

[969] Kiefer, A. K., & Sekaquaptewa D.
(2007).  Implicit stereotypes, gender identification, and math-related outcomes: a prospective study of female college students.
Psychological Science: A Journal of the American Psychological Society / APS. 18(1), 13 - 18.

http://www.eurekalert.org/pub_releases/2007-01/afps-isa012407.php

Women's math performance affected by theories on sex differences

In a salutary reminder to all researchers into gender and race differences, researchers found that women who received a genetic explanation for female underachievement in math or were reminded of the stereotype about female math underachievement, performed more poorly on math tests than those who received an experiential explanation (such as math teachers treating boys preferentially during the first years of math education) or were led to believe there are no sex differences in math.

[1024] Dar-Nimrod, I., & Heine S. J.
(2006).  Exposure to Scientific Theories Affects Women's Math Performance.
Science. 314(5798), 435 - 435.

http://www.eurekalert.org/pub_releases/2006-10/uobc-wmp101306.php

Memory problems at menopause

Findings from a study of 24 women approaching menopause have confirmed an earlier study involving over 800 women that found such women are no more likely than anyone else to suffer from memory retrieval problems. However, they did find that the women who complained more about problems with forgetfulness had a harder time learning or "encoding" new information, although they didn’t have actually have an impaired ability to learn new information. Although a larger study is needed to explore this link in more detail, the researchers suggest that stress and emotional upheaval may be responsible for attention failures that mean information isn’t encoded. The researchers did find that most of the women in their study had some sort of mood distress, including symptoms of depression or anxiety (note that this was not a random group, but women who were worried about their memory).

The study was reported at the annual meeting of the International Neuropsychological Society in Boston.

http://www.eurekalert.org/pub_releases/2006-02/uorm-mpa020206.php

Brain size does matter, but differently for men and women

A study involving the intelligence testing of 100 neurologically normal, terminally ill volunteers, who agreed that their brains be measured after death, found that a bigger brain size is correlated with higher intelligence in certain areas, but there are differences between women and men. Verbal intelligence was clearly correlated with brain size, accounting for 36% of the verbal IQ score, for women and right-handed men — but not for left-handed men. Spatial intelligence was also correlated with brain size in women, but much less strongly, while it was not related at all to brain size in men. It may be that the size or structure of specific brain regions is related to spatial intelligence in men. Brain size decreased with age in men over the age span of 25 to 80 years, suggesting that the well-documented decline in visuospatial intelligence with age is related, at least in right-handed men, to the decrease in cerebral volume with age. However age hardly affected brain size in women.

[1029] Witelson, S. F., Beresh H., & Kigar D. L.
(2006).  Intelligence and brain size in 100 postmortem brains: sex, lateralization and age factors.
Brain: A Journal of Neurology. 129(Pt 2), 386 - 398.

http://www.sciencedaily.com/releases/2005/12/051223123116.htm

Effect of pregnancy on cognition depends on fetal gender

An intriguing new study may shed light on the conflicting results reported regarding the effect of pregnancy on cognition. The study, which tracked women throughout pregnancy through to postnatal resumption of menstruation, found that there was a significant effect of the sex of the baby on working memory and spatial ability. Women pregnant with boys consistently outperformed women pregnant with girls on these tests.

[1187] Vanston, C. M., & Watson N. V.
(2005).  Selective and persistent effect of foetal sex on cognition in pregnant women.
Neuroreport. 16(7), 779 - 782.

Cognitive effects of binge drinking worse for women

A new study looked at the cognitive effects of binge drinking, which apparently is on the rise in several countries, including Britain and the US. The study involved 100 healthy moderate-to-heavy social drinkers aged between 18 and 30. There were equal numbers of males and females. The study found that female binge drinkers performed worse on the working-memory and vigilance tasks than did the female non-binge drinkers.

[1311] Townshend, J. M., & Duka T.
(2005).  Binge Drinking, Cognitive Performance and Mood in a Population of Young Social Drinkers.
Alcoholism: Clinical and Experimental Research. 29(3), 317 - 325.

http://www.eurekalert.org/pub_releases/2005-03/ace-bdc030705.php

The effects of training and age on the spatial-memory gender gap

A study of 90 adult rhesus monkeys found young-adult males had better spatial memory than females, but peaked early. By old age, male and female monkeys had about the same performance. This finding is consistent with reports suggesting that men show greater age-related cognitive decline relative to women. A second study of 22 rhesus monkeys showed that in young adulthood, simple spatial-memory training did not help males but dramatically helped females, raising their performance to the level of young-adult males and wiping out the gender gap.

[1193] Lacreuse, A., Kim C. B., Rosene D. L., Killiany R. J., Moss M. B., Moore T. L., et al.
(2005).  Sex, Age, and Training Modulate Spatial Memory in the Rhesus Monkey (Macaca mulatta)..
Behavioral Neuroscience. 119(1), 118 - 126.

http://www.eurekalert.org/pub_releases/2005-02/apa-ima022205.php
http://www.eurekalert.org/pub_releases/2005-02/euhs-npm020905.php
http://www.sciam.com/article.cfm?articleID=000560D5-7252-12B9-9A2C83414B7F0000&sc=I100322

Faster neuron transmission in young males

A study of 186 male and 201 female students (aged 18-25) has found that men's brain cells can transmit nerve impulses 4% faster than women's, probably due to the faster increase of white matter in the male brain during adolescence.

[1034] Reed, E. T., Vernon P. A., & Johnson A. M.
(Submitted).  Confirmation of correlation between brain nerve conduction velocity and intelligence level in normal adults.
Intelligence. 32(6), 563 - 572.

IQ-related brain areas may differ in men and women

An imaging study of 48 men and women between 18 and 84 years old found that, although men and women performed equally on the IQ tests, the brain structures involved in intelligence appeared distinct. Compared with women, men had more than six times the amount of intelligence-related gray matter, while women had about nine times more white matter involved in intelligence than men did. Women also had a large proportion of their IQ-related brain matter (86% of white and 84% of gray) concentrated in the frontal lobes, while men had 90% of their IQ-related gray matter distributed equally between the frontal lobes and the parietal lobes, and 82% of their IQ-related white matter in the temporal lobes. The implications of all this are not clear, but it is worth noting that the volume of gray matter can increase with learning, and is thus a product of environment as well as genes. The findings also demonstrate that no single neuroanatomical structure determines general intelligence and that different types of brain designs are capable of producing equivalent intellectual performance.

[938] Haier, R. J., Jung R. E., Yeo R. A., Head K., & Alkire M. T.
(2005).  The neuroanatomy of general intelligence: sex matters.
NeuroImage. 25(1), 320 - 327.

http://www.eurekalert.org/pub_releases/2005-01/uoc--iim012005.php
http://www.sciencedaily.com/releases/2005/01/050121100142.htm

Estrogen combines with stress to impair memory

A rat study has found that male and female rats performed equally well on a task involving the prefrontal cortex when under no stress, and when highly stressed, both made significant memory errors. But importantly, after exposure to a moderate level of stress, females were impaired, but males were not. When investigated further, it was found that female rats only showed this sensitivity when they were in a high-estrogen phase of their estrus cycle. The estrogen effect was confirmed in a further study using female rats who had had their ovaries removed, thus enabling the researchers to compare the effects of estrogen versus a placebo. These results suggest that high levels of estrogen can act to enhance the stress response, causing greater stress-related cognitive impairments, while providing reassurance that estrogen appears to have no effect on cognitive performance under non-stressful conditions.

[746] Shansky, R. M., Glavis-Bloom C., Lerman D., McRae P., Benson C., Miller K., et al.
(2003).  Estrogen mediates sex differences in stress-induced prefrontal cortex dysfunction.
Mol Psychiatry. 9(5), 531 - 538.

http://www.eurekalert.org/pub_releases/2003-12/mp-epg112603.php

No support for idea that pregnancy affects memory and concentration

A study of pregnant women found many agreed with the popular view that pregnancy affects your memory. However, mental tests during pregnancy and after the birth found no difference between the performance of women who were pregnant and those who were not. It was possible that the affects are too mild to be picked up by the tests, or that the fatigue commonly experienced by women during pregnancy and early motherhood leads women to believe that their memory and concentration are affected.

The research was presented at the British Psychological Society annual conference in Bournemouth.

http://news.bbc.co.uk/1/hi/health/2847797.stm

Women better at recognizing female but not male faces

Women’s superiority in face recognition tasks appears to be due to their better recognition of female faces. There was no difference between men and women in the recognition of male faces.

[671] Lewin, C., & Herlitz A.
(2002).  Sex differences in face recognition--Women's faces make the difference.
Brain and Cognition. 50(1), 121 - 128.

Why women better remember emotional memories

A new brain imaging study reveals gender differences in the encoding of emotional memories. We have long known that women are better at remembering emotional memories, now we can see that the sexes tend to encode emotional experiences in different parts of the brain. In women, it seems that evaluation of emotional experience and encoding of the memory is much more tightly integrated.

[807] Canli, T., Desmond J. E., Zhao Z., & Gabrieli J. D. E.
(2002).  Sex differences in the neural basis of emotional memories.
Proceedings of the National Academy of Sciences of the United States of America. 99(16), 10789 - 10794.

http://www.newscientist.com/news/news.jsp?id=ns99992576

Gender differences in frontal lobe neuron density

A recent study has found that women have up to 15% more brain cell density in the frontal lobe, which controls so-called higher mental processes, such as judgement, personality, planning and working memory. However, as they get older, women appear to shed cells more rapidly from this area than men. By old age, the density is similar for both sexes. It is not yet clear what impact, if any, this difference has on performance.

Witelson, S.F., Kigar, D.L. & Stoner-Beresh, H.J. 2001. Sex difference in the numerical density of neurons in the pyramidal layers of human prefrontal cortex: a stereologic study. Paper presented to the annual Society for Neuroscience meeting in San Diego, US.

http://news.bbc.co.uk/hi/english/health/newsid_1653000/1653687.stm

Gender differences in neural networks underlying beginning reading

A recent study uses EEG readings to investigate gender differences in the emerging connectivity of neural networks associated with phonological processing, verbal fluency, higher-level thinking and word retrieval (skills needed for beginning reading), in preschoolers. The study confirms different patterns of growth in building connections between boys and girls. These differences point to the different advantages each gender brings to learning to read. Boys favor vocabulary sub-skills needed for comprehension while girls favor fluency and phonic sub-skills needed for the mechanics of reading.

Hanlon, H. 2001. Gender Differences Observed in Preschoolers’ Emerging Neural Networks. Paper presented at Genomes and Hormones: An Integrative Approach to Gender Differences in Physiology, an American Physiological Society (APS) conference held October 17-20 in Pittsburgh.

http://www.eurekalert.org/pub_releases/2001-10/aps-gad101701.php

Boys' and girls' brains process faces differently

Previous research has suggested a right-hemisphere superiority in face processing, as well as adult male superiority at spatial and non-verbal skills (also associated with the right hemisphere of the brain). This study looked at face recognition and the ability to read facial expressions in young, pre-pubertal boys and girls. Boys and girls were equally good at recognizing faces and identifying expressions, but boys showed significantly greater activity in the right hemisphere, while the girls' brains were more active in the left hemisphere. It is speculated that boys tend to process faces at a global level (right hemisphere), while girls process faces at a more local level (left hemisphere). This may mean that females have an advantage in reading fine details of expression. More importantly, it may be that different treatments might be appropriate for males and females in the case of brain injury.

[2541] Everhart, E. D., Shucard J. L., Quatrin T., & Shucard D. W.
(2001).  Sex-related differences in event-related potentials, face recognition, and facial affect processing in prepubertal children.
Neuropsychology. 15(3), 329 - 341.

http://www.eurekalert.org/pub_releases/2001-07/aaft-pba062801.php
http://news.bbc.co.uk/hi/english/health/newsid_1425000/1425797.stm

More women than men do well on memory tests in old age

Researchers from Leiden University tested the mental functioning of 599 Dutch men and women aged 85 years. Good mental speed on word and number recognition tests was found in 33% of the women and 28% of the men. Forty one per cent of the women and 29% of the men had a good memory. This despite the fact that significantly more of the women had limited formal education compared to the men (not surprising given the time in which they grew up). The authors suggested that biological differences - such as the relative absence of cardiovascular disease in elderly women compared with men of the same age - could account for these sex differences in mental decline.

[2615] van Exel, E., Gussekloo J., de Craen A. J. M., Bootsma-van der Wiel A., Houx P., Knook D. L., et al.
(2001).  Cognitive function in the oldest old: women perform better than men.
Journal of Neurology, Neurosurgery & Psychiatry. 71(1), 29 - 32.

http://www.eurekalert.org/pub_releases/2001-06/BSJ-Ewhb-1706101.php

tags memworks: 

Intelligence

Older news items (pre-2010) brought over from the old website

Aerobic fitness boosts IQ in teenage boys

Data from the 1.2 million Swedish men born between 1950 and 1976 who enlisted for mandatory military service at the age of 18 has revealed that on every measure of cognitive performance, average test scores increased according to aerobic fitness — but not muscle strength. The link was strongest for logical thinking and verbal comprehension, and the association was restricted to cardiovascular fitness. The results of the study also underline the importance of getting healthier between the ages of 15 and 18 while the brain is still changing — those who improved their cardiovascular health between 15 and 18 showed significantly greater intelligence scores than those who became less healthy over the same time period. Those who were fittest at 18 were also more likely to go to college. Although association doesn’t prove cause, the fact that the association was only with cardiovascular fitness and not strength supports a cardiovascular effect on brain function. Results from over 260,000 full-sibling pairs, over 3,000 sets of twins, and more than 1,400 sets of identical twins, also supports a causal relationship.

[1486] Åberg, M AI., Pedersen N. L., Torén K., Svartengren M., Bäckstrand B., Johnsson T., et al.
(2009).  Cardiovascular fitness is associated with cognition in young adulthood.
Proceedings of the National Academy of Sciences. 106(49), 20906 - 20911.

http://www.physorg.com/news179415275.html
http://www.telegraph.co.uk/science/science-news/6692474/Physical-health-leads-to-mental-health.html

Confidence as important as IQ in exam success

I’ve talked repeatedly about the effects of self-belief on memory and cognition. One important area in which this is true is that of academic achievement. Evidence indicates that your perceived abilities matter, just as much? more than? your actual abilities. It has been assumed that self perceived abilities, self-confidence if you will, is a product mainly of nurture. Now a new twin study provides evidence that nurture / environment may only provide half the story; the other half may lie in the genes. The study involved 1966 pairs of identical twins and 1877 pairs of fraternal twins. The next step is to tease out which of these genes are related to IQ and which to personality variables.

[1080] Greven, C. U., Harlaar N., Kovas Y., Chamorro-Premuzic T., & Plomin R.
(2009).  More Than Just IQ: School Achievement Is Predicted by Self-Perceived Abilities—But for Genetic Rather Than Environmental Reasons.
Psychological Science. 20(6), 753 - 762.

http://www.newscientist.com/article/dn17187-confidence-as-important-as-iq-in-exam-success.html

Children of older fathers perform less well in intelligence tests during infancy

Reanalysis of a dataset of over 33,000 children born between 1959 and 1965 and tested at 8 months, 4 years, and 7 years, has revealed that the older the father, the more likely the child was to have lower scores on the various tests used to measure the ability to think and reason, including concentration, learning, memory, speaking and reading skills. In contrast, the older the mother, the higher the scores of the child in the cognitive tests.

[1447] Saha, S., Barnett A. G., Foldi C., Burne T. H., Eyles D. W., Buka S. L., et al.
(2009).  Advanced Paternal Age Is Associated with Impaired Neurocognitive Outcomes during Infancy and Childhood.
PLoS Med. 6(3), e1000040 - e1000040.

Full text available at http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.1000040

http://www.eurekalert.org/pub_releases/2009-03/plos-coo030309.php

Brain-training to improve working memory boosts fluid intelligence

General intelligence is often separated into "fluid" and "crystalline" components, of which fluid intelligence is considered more reflective of “pure” intelligence (for more on this, see my article), and largely resistant to training and learning effects. However, in a new study in which participants were given a series of training exercises designed to improve their working memory, fluid intelligence was found to have significantly improved, with the amount of improvement increasing with time spent training. The small study contradicts decades of research showing that improving on one kind of cognitive task does not improve performance on other kinds, so has been regarded with some skepticism by other researchers. More research is definitely needed, but the memory task did differ from previous studies, engaging executive functions such as those that inhibit irrelevant items, monitor performance, manage two tasks simultaneously, and update memory.

[1183] Jaeggi, S. M., Buschkuehl M., Jonides J., & Perrig W. J.
(2008).  From the Cover: Improving fluid intelligence with training on working memory.
Proceedings of the National Academy of Sciences. 105(19), 6829 - 6833.

http://www.physorg.com/news128699895.html
http://www.sciam.com/article.cfm?id=study-shows-brain-power-can-be-bolstered

Effect of schooling on achievement gaps within racial groups

Analysis of data from a national sample (U.S.) of 8,060 students, collected at four points in time, starting in kindergarten and ending in the spring of fifth grade, has found evidence that education has an impact in closing the achievement gap for substantial numbers of children. High-performing groups in reading were found among all races. About 30% of European Americans, 26% of African Americans and 45% of Asian Americans were in high-achieving groups by the spring of fifth grade — these groups included approximately 23% of African American children and 36% of Asian children who caught up with the initial group of high achievers over time. Only around 4% of European American students were in catch-up groups, because a higher percentage of European Americans started kindergarten as high achievers in reading. The situation was different for Hispanic students, however.  By the end of fifth grade, just over 5% of Hispanic children were high achievers in reading, while the remainder tested in the middle range. There were no low achievers and no catch-up groups. A different pattern was found in math. Only 17% of European American students were high-achievers in math by the end of fifth grade, including 13% who started kindergarten at a lower achievement level and caught up over time.  About 18% of Asian Americans were high-achievers at the end of fifth grade (11% catch-up). Only 0.3% of African Americans were high achievers at the end of fifth grade, and 26% were medium-high achievers. But about 16% of Hispanics were high achievers in math. There were no catch-up groups for either the African Americans or the Hispanics. This suggests that current schooling doesn't have as strong an impact on math achievement as it does in reading.

The study was presented in Washington, D.C. at the 2008 annual meeting of the Society for Research on Educational Effectiveness.

http://www.physorg.com/news123859991.html

Autism non-verbal not unintelligent

New findings suggest that the association of autism with low intelligence is a product of their language difficulties. Testing autistic kids and normal kids on two popular IQ tests — the WISC (which relies heavily on language) and Raven's Progressive Matrices (considered the best test of "fluid intelligence", and a test that doesn't require much language) found that while not a single autistic child scored in the "high intelligence" range of the WISC, a third did on the Raven's. A third of the autistics had WISC scores in the mentally retarded range, but only one in 20 scored that low on the Raven's test. The non-autistic children scored similarly on both tests. The same results occurred when the experiment was run on autistic and normal adults.

[580] Dawson, M., Soulières I., Gernsbacher M A., & Mottron L.
(2007).  The level and nature of autistic intelligence.
Psychological Science: A Journal of the American Psychological Society / APS. 18(8), 657 - 662.

http://www.physorg.com/news105376203.html
http://www.eurekalert.org/pub_releases/2007-08/afps-tmo080307.php

Being treated as oldest linked to IQ

The question of whether there is an IQ advantage to being the first-born has long been debated. Now analysis of IQ test results of 241,310 Norwegians drafted into the armed forces between 1967 and 1976 has revealed that the average IQ of first-born men was 103.2 while second-born men averaged 101.2 and third-borns, 100.0. However, second-born men whose older sibling died in infancy scored 102.9, and if both older siblings died young, the third-born score rose to 102.6. This suggests the advantage lies in the social rank in the family and not birth order as such.

[589] Kristensen, P., & Bjerkedal T.
(2007).  Explaining the Relation Between Birth Order and Intelligence.
Science. 316(5832), 1717 - 1717.

http://www.nature.com/news/2007/070618/full/070618-14.html

Executive function as important as IQ for math success

A study of 141 preschoolers from low-income homes has found that a child whose IQ and executive functioning were both above average was three times more likely to succeed in math than a child who simply had a high IQ. The parts of executive function that appear to be particularly linked to math ability in preschoolers are working memory and inhibitory control. In this context, working memory may be thought of as the ability to keep information or rules in mind while performing mental tasks. Inhibitory control is the ability to halt automatic impulses and focus on the problem at hand. Inhibitory control was also important for reading ability. The finding offers the hope that training to improve executive function will improve academic performance.

[1256] Blair, C., & Razza R P.
(2007).  Relating Effortful Control, Executive Function, and False Belief Understanding to Emerging Math and Literacy Ability in Kindergarten.
Child Development. 78(2), 647 - 663.

http://www.sciam.com/article.cfm?articleID=90377FAE-E7F2-99DF-3A1204FC5F2BF0F7

Students who believe intelligence can be developed perform better

Research with 12-year-olds has found that, although all students began the study with equivalent achievement levels in math, over a two year period, those who believed that intelligence was malleable increasingly did better than those who believed their intelligence was fixed. Another study found that, when students showing declines in their math grades were taught that intelligence could be increased, they reversed their decline and showed significantly higher math grades than others who weren’t taught that.

[1123] Blackwell, L. S., Trzesniewski K. H., & Dweck C S.
(2007).  Implicit Theories of Intelligence Predict Achievement across an Adolescent Transition: A Longitudinal Study and an Intervention.
Child Development. 78(1), 246 - 263.

http://www.eurekalert.org/pub_releases/2007-02/sfri-swb013107.php

Implicit stereotypes and gender identification may affect female math performance

Relatedly, another study has come out showing that women enrolled in an introductory calculus course who possessed strong implicit gender stereotypes, (for example, automatically associating "male" more than "female" with math ability and math professions) and were likely to identify themselves as feminine, performed worse relative to their female counterparts who did not possess such stereotypes and who were less likely to identify with traditionally female characteristics. Strikingly, a majority of the women participating in the study explicitly expressed disagreement with the idea that men have superior math ability, suggesting that even when consciously disavowing stereotypes, female math students are still susceptible to negative perceptions of their ability.

[969] Kiefer, A. K., & Sekaquaptewa D.
(2007).  Implicit stereotypes, gender identification, and math-related outcomes: a prospective study of female college students.
Psychological Science: A Journal of the American Psychological Society / APS. 18(1), 13 - 18.

http://www.eurekalert.org/pub_releases/2007-01/afps-isa012407.php

Reducing the racial achievement gap

And staying with the same theme, a study that came out six months ago, and recently reviewed on the excellent new Scientific American Mind Matters blog, revealed that a single, 15-minute intervention erased almost half the racial achievement gap between African American and white students. The intervention involved writing a brief paragraph about which value, from a list of values, was most important to them and why. The intervention improved subsequent academic performance for some 70% of the African American students, but none of the Caucasians. The study was repeated the following year with the same results. It is thought that the effect of the intervention was to protect against the negative stereotypes regarding the intelligence and academic capabilities of African Americans.

[1082] Cohen, G. L., Garcia J., Apfel N., & Master A.
(2006).  Reducing the Racial Achievement Gap: A Social-Psychological Intervention.
Science. 313(5791), 1307 - 1310.

Fitness and childhood IQ indicators of cognitive ability in old age

Data from the Scottish Mental Survey of 1932 has revealed that physical fitness contributed more than 3% of the differences in cognitive ability in old age. The study involved 460 men and women, who were tested using the same cognitive test at age 79 that they had undergone at age 11. Physical fitness was defined by time to walk six meters, grip strength and lung function. Childhood IQ was also significantly related to lung function at age 79, perhaps because people with higher intelligence might respond more favorably to health messages about staying fit. But physical fitness was more important for cognitive ability in old age than childhood IQ. People in more professional occupations and with more education also had better fitness and higher cognitive test scores at 79.

[770] Deary, I. J., Whalley L. J., Batty D. G., & Starr J. M.
(2006).  Physical fitness and lifetime cognitive change.
Neurology. 67(7), 1195 - 1200.

http://www.eurekalert.org/pub_releases/2006-10/aaon-fac100306.php

Black-white IQ gap has narrowed

Data now available suggests that Black Americans have gained an average of .18 IQ points a year on White Americans from 1972 to 2002 for a total gain of 5.4 IQ points.

[929] Dickens, W. T., & Flynn J. R.
(2006).  Black Americans reduce the racial IQ gap: evidence from standardization samples.
Psychological Science: A Journal of the American Psychological Society / APS. 17(10), 913 - 920.

http://www.eurekalert.org/pub_releases/2006-09/afps-big091206.php

Does IQ drop with age or does something else impact intelligence?

As people grow older, their IQ scores drop. But is it really that they lose intelligence? A study has found that if college students had to perform under conditions that mimic the perception deficits many older people have, their IQ scores would also take a drop.

[234] Gilmore, G. C., Spinks R. A., & Thomas C. W.
(2006).  Age effects in coding tasks: componential analysis and test of the sensory deficit hypothesis.
Psychology and Aging. 21(1), 7 - 18.

http://www.eurekalert.org/pub_releases/2006-05/cwru-did050106.php

Smarter kids may live longer

A prospective study that recruited 897 individuals who scored 135 or higher on the Stanford-Binet IQ test in 1922 has found that higher IQs were associated with longevity, with the survival advantage leveling off after a childhood IQ of 163. The association was independent of childhood social position (as measured by father’s occupation). The study confirms earlier research suggesting an association between IQ and mortality, and provides the new finding of where the cut-off point (when high IQ no longer brought additional health benefits) appears — the cutoff of 163 was much higher than expected. Suggested reasons for the association (all of which may well be valid) include: greater tendency to adopt healthy habits and avoid bad ones; increased probability of better jobs; better skills for managing their health and the health-care system.

[690] Martin, L. T., & Kubzansky L. D.
(2005).  Childhood Cognitive Performance and Risk of Mortality: A Prospective Cohort Study of Gifted Individuals.
Am. J. Epidemiol.. 162(9), 887 - 890.

http://health.yahoo.com/news/126478

Growing up in a chaotic home may impair child's cognitive development

An association between disorganized, noisy and cramped homes and lower childhood intelligence has been observed before, but the reasons for the association have never been clear. Now a study of some 8000 3- and 4-year-old twins has perhaps disentangled the variables, and has found that chaos had an influence on cognitive skills independent of socioeconomic status. The findings also suggest that when the environment is more stressful, intelligence is more likely to be constrained by genes.

[570] Petrill, S. A., Pike A., Price T., & Plomin R.
(Submitted).  Chaos in the home and socioeconomic status are associated with cognitive development in early childhood: Environmental mediators identified in a genetic design.
Intelligence. 32(5), 445 - 460.

http://www.newscientist.com/news/news.jsp?id=ns99996323

Early music instruction raises child’s IQ

A new study confirms earlier research supporting the benefits of early music instruction. The study involved 144 children, 6 years old at the start of the study. They were given free weekly voice or piano lessons at the Royal Conservatory of Music. Another group of 6-year-olds was given free training in weekly drama classes, while a fourth group received no extra classes during the study period. Before any classes were given, all the children were tested using the full Weschler intelligence test. At the end of the school year (their first school year), the children were retested. All had an IQ increase of at least 4.3 points on average (a consequence of going to school). Children who took drama lessons scored no higher than those who had no extra lessons, but those who took music lessons scored on average 2.7 points higher than the children who did not take music lessons. Those in the drama group did however show substantial improvement in adaptive social behavior.

[1009] Schellenberg, E. Glenn
(2004).  Music lessons enhance IQ.
Psychological Science: A Journal of the American Psychological Society / APS. 15(8), 511 - 514.

http://www.sciencentral.com/articles/view.htm3?article_id=218392326

Knowledge-based IQ test predicts work performance as well as school

A meta-analysis of 127 studies supports the view that the Miller Analogies Test (MAT) — a knowledge-based test used for admissions decisions into U.S. graduate schools as well as in hiring and promotion decisions in the workplace since 1926 — is predictive of performance in both the academic and workplace environments. Specifically, MAT was a valid predictor of seven of the eight measures of graduate student performance, five of the six school-to-work transition performance criteria, and all four of the work performance criteria. MAT is assumed to measure “g”, the oft-debated “general intelligence” factor.

[1109] Kuncel, N. R., Hezlett S. A., & Ones D. S.
(2004).  Academic Performance, Career Potential, Creativity, and Job Performance: Can One Construct Predict Them All?.
Journal of Personality and Social Psychology. 86(1), 148 - 161.

Support for "general intelligence" factor

Researchers into intelligence and memory have always concentrated on verbal abilities — for the good reason that they are considerably easier to test. New research suggests that strong visuospatial skills and working memory may be at least as good as verbal skills and working memory as indicators of general intelligence. The study, involving 167 subjects, found a clear relationship between being good at complex visuospatial tasks, and being good at tasks involving the so-called “central executive” (which coordinates tasks, sets goals, etc). The study lends support both to the view that intelligence has both discrete components and a general aspect, and that this “general intelligence” may be related to executive functioning.

[1152] Miyake, A., Friedman N. P., Rettinger D. A., Shah P., & Hegarty M.
(2001).  How are visuospatial working memory, executive functioning, and spatial abilities related? A latent-variable analysis.
Journal of Experimental Psychology. General. 130(4), 621 - 640.

http://www.eurekalert.org/pub_releases/2001-12/apa-npo121001.php

tags memworks: 

tags strategies: 

Repetition is behind our improved memory for emotional events

December, 2011

A new study concludes that positive events tend to be remembered better than negative, but the more important finding is that being repeatedly reminded of the event is the main factor behind improved memory for emotional experiences.

Certainly experiences that arouse emotions are remembered better than ones that have no emotional connection, but whether negative or positive memories are remembered best is a question that has produced equivocal results. While initial experiments suggested positive events were remembered better than negative, more recent studies have concluded the opposite.

The idea that negative events are remembered best is consistent with a theory that negative emotion signals a problem, leading to more detailed processing, while positive emotion relies more heavily on general scripts.

However, a new study challenges those recent studies, on the basis of a more realistic comparison. Rather than focusing on a single public event, to which some people have positive feelings while others have negative feelings (events used have included the OJ Simpson trial, the fall of the Berlin Wall, and a single baseball championship game), the study looked at two baseball championships each won by different teams.

The experiment involved 1,563 baseball fans who followed or attended the 2003 and 2004 American League Championship games between the New York Yankees (2003 winners) and the Boston Red Sox (2004 winners). Of the fans, 1,216 were Red Sox fans, 218 were Yankees fans, and 129 were neutral fans. (Unfortunately the selection process disproportionately collected Red Sox fans.)

Participants were reminded who won the championship before answering questions on each game. Six questions were identical for the two games: the final score for each team, the winning and losing pitchers (multiple choice of five pitchers for each team), the location of the game, and whether the game required extra innings. Participants also reported how vividly they remembered the game, and how frequently they had thought about or seen media concerning the game.

Both Yankee and Red Sox fans remembered more details about their team winning. They also reported more vivid memories for the games their team won. Accuracy and vividness were significantly correlated. Fans also reported greater rehearsal of the game their team won, and again, rehearsal and accuracy were significantly correlated.

Analysis of the data revealed that rehearsal completely mediated the correlation between accuracy and fan type, and partially mediated the correlation between vividness and fan type.

In other words, improved memory for emotion-arousing events has everything to do with how often you think about or are reminded of the event.

PTSD, for example, is the negative memory extreme. And PTSD is characterized by the unavoidable rehearsal of the event over and over again. Each repetition makes memory for the event stronger.

In the previous studies referred to earlier, media coverage provided a similarly unavoidable repetition.

While most people tend to recall more positive than negative events (and this tendency becomes greater with age), individuals who are depressed or anxious show the opposite tendency.

So whether positive or negative events are remembered better depends on you, as well as the event.

When it comes down to it, I'm not sure it's really a helpful question - whether positive or negative events are remembered better. An interesting aspect of public events is that their portrayal often changes over time, but this is just a more extreme example of what happens with private events as well — as we change over time, so does our attitude toward those events. Telling friends about events, and receiving their comments on them, can affect our emotional response to events, as well as having an effect on our memory of those events.

Reference: 

[2591] Breslin, C. W., & Safer M. A.
(2011).  Effects of Event Valence on Long-Term Memory for Two Baseball Championship Games.
Psychological Science. 22(11), 1408 - 1412.

Source: 

Topics: 

tags memworks: 

Memory genes vary in protecting against age-related cognitive decline

November, 2011

New findings show the T variant of the KIBRA gene improves episodic memory through its effect on hippocampal activity. Another study finds the met variant of the BDNF gene is linked to greater age-related cognitive decline.

Previous research has found that carriers of the so-called KIBRA T allele have been shown to have better episodic memory than those who don’t carry that gene variant (this is a group difference; it doesn’t mean that any carrier will remember events better than any non-carrier). A large new study confirms and extends this finding.

The study involved 2,230 Swedish adults aged 35-95. Of these, 1040 did not have a T allele, 932 had one, and 258 had two.  Those who had at least one T allele performed significantly better on tests of immediate free recall of words (after hearing a list of 12 words, participants had to recall as many of them as they could, in any order; in some tests, there was a concurrent sorting task during presentation or testing).

There was no difference between those with one T allele and those with two. The effect increased with increasing age. There was no effect of gender. There was no significant effect on performance of delayed category cued recall tests or a visuospatial task, although a trend in the appropriate direction was evident.

It should also be noted that the effect on immediate recall, although statistically significant, was not large.

Brain activity was studied in a subset of this group, involving 83 adults aged 55-60, plus another 64 matched on sex, age, and performance on the scanner task. A further group of 113 65-75 year-olds were included for comparison purposes. While in the scanner, participants carried out a face-name association task. Having been presented with face-name pairs, participants were tested on their memory by being shown the faces with three letters, of which one was the initial letter of the name.

Performance on the scanner task was significantly higher for T carriers — but only for the 55-60 age group, not for the 65-75 age group. Activity in the hippocampus was significantly higher for younger T carriers during retrieval, but not encoding. No such difference was seen in the older group.

This finding is in contrast with an earlier, and much smaller, study involving 15 carriers and 15 non-carriers, which found higher activation of the hippocampus in non-T carriers. This was taken at the time to indicate some sort of compensatory activity. The present finding challenges that idea.

Although higher hippocampal activation during retrieval is generally associated with faster retrieval, the higher activity seen in T carriers was not fully accounted for by performance. It may be that such activity also reflects deeper processing.

KIBRA-T carriers were neither more nor less likely to carry other ‘memory genes’ — APOEe4; COMTval158met; BDNFval66met.

The findings, then, fail to support the idea that non-carriers engage compensatory mechanisms, but do indicate that the KIBRA-T gene helps episodic memory by improving the hippocampus function.

BDNF gene variation predicts rate of age-related decline in skilled performance

In another study, this time into the effects of the BDNF gene, performance on an airplane simulation task on three annual occasions was compared. The study involved 144 pilots, of whom all were healthy Caucasian males aged 40-69, and 55 (38%) of whom turned out to have at least one copy of a BDNF gene that contained the ‘met’ variant. This variant is less common, occurring in about one in three Asians, one in four Europeans and Americans, and about one in 200 sub-Saharan Africans.  

While performance dropped with age for both groups, the rate of decline was much steeper for those with the ‘met’ variant. Moreover, there was a significant inverse relationship between age and hippocampal size in the met carriers — and no significant correlation between age and hippocampal size in the non-met carriers.

Comparison over a longer time-period is now being undertaken.

The finding is more evidence for the value of physical exercise as you age — physical activity is known to increase BDNF levels in your brain. BDNF levels tend to decrease with age.

The met variant has been linked to higher likelihood of depression, stroke, anorexia nervosa, anxiety-related disorders, suicidal behavior and schizophrenia. It differs from the more common ‘val’ variant in having methionine rather than valine at position 66 on this gene. The BDNF gene has been remarkably conserved across evolutionary history (fish and mammalian BDNF have around 90% agreement), suggesting that mutations in this gene are not well tolerated.

Reference: 

Source: 

Topics: 

tags development: 

tags memworks: 

tags problems: 

Another challenge to idea that men are better at spatial thinking

October, 2011

A cross-cultural study finds a significant gender difference on a simple puzzle problem for one culture but no gender difference for another. The difference was only partly explained by education.

Here’s an intriguing approach to the long-standing debate about gender differences in spatial thinking. The study involved 1,279 adults from two cultural groups in India. One of these groups was patrilineal, the other matrilineal. The volunteers were given a wooden puzzle to assemble as quickly as they could.

Within the patrilineal group, men were on average 36% faster than women. Within the matrilineal group, however, there was no difference between the genders.

I have previously reported on studies showing how small amounts of spatial training can close the gap in spatial abilities between the genders. It has been argued that in our culture, males are directed toward spatial activities (construction such as Lego; later, video games) more than females are.

In this case, the puzzle was very simple. However, general education was clearly one factor mediating this gender difference. In the patrilineal group, males had an average 3.67 more years of education, while in the matrilineal group, men and women had the same amount of education. When education was included in the statistical analysis, a good part of the difference between the groups was accounted for — but not all.

While we can only speculate about the remaining cause, it is interesting to note that, among the patrilineal group, the gender gap was decidedly smaller among those who lived in households not wholly owned by males (in the matrilineal group, men are not allowed to own property, so this comparison cannot be made).

It is also interesting to note that the men in the matrilineal group were faster than the men in the patrilineal group. This is not a function of education differences, because education in the matrilineal group was slightly less than that of males in the patrilineal group.

None of the participants had experience with puzzle solving, and both groups had similar backgrounds, being closely genetically related and living in villages geographically close. Participants came from eight villages: four patrilineal and four matrilineal.

Reference: 

[2519] Hoffman, M., Gneezy U., & List J. A.
(2011).  Nurture affects gender differences in spatial abilities.
Proceedings of the National Academy of Sciences. 108(36), 14786 - 14788.

Source: 

Topics: 

tags memworks: 

Emotion

Older news items (pre-2010) brought over from the old website

How emotion affects memory (general)

Mixed feelings not remembered as well as happy or sad ones

A series of studies that tested participants' emotions when they faced scenarios such as taking tests and moving, events that are typically associated with mixed emotions, has found that the intensity of mixed emotions tends to be underestimated when recalling the experience. This underestimation increases over time, to the point that people sometimes don't remember having felt ambivalent at all. This is more likely among those who are uncomfortable feeling mixed emotions. Interestingly, Asian Americans in the study did not exhibit the same degree of memory decline for mixed emotions as Anglo-Americans did.

Aaker, J., Drolet, A. & Griffin, D. 2008. Recalling Mixed Emotions. Journal of Consumer Research, 35 (2), 268-278.

http://www.eurekalert.org/pub_releases/2008-06/uocp-mfn062508.php

Emotions help memory, at the cost of other memories

Do we remember emotionally charged events better? Maybe — but at a price. A new study presented volunteers with lists of neutral words with one disturbing noun, such as murder or scream, embedded. As expected, the emotional words were much better remembered than the neutral words. More interestingly, the poorest memory occurred for neutral words that were presented immediately before the disturbing words. The effect was greater for women — women forgot those words twice as often as men.

[214] Strange, B. A., Hurlemann R., & Dolan R. J.
(2003).  An emotion-induced retrograde amnesia in humans is amygdala- and beta-adrenergic-dependent.
Proceedings of the National Academy of Sciences of the United States of America. 100(23), 13626 - 13631.

http://www.sciencenews.org/20031108/fob5.asp

How memory helps make life pleasant

Surveys consistently show that people are generally happy with their lives. A review of research into autobiographical memory suggests why - human memory is biased toward happiness. Across 12 studies conducted by five different research teams, people of different racial and ethnic backgrounds and of different ages consistently reported experiencing more positive events in their lives than negative events, suggesting that pleasant events do in fact outnumber unpleasant events because people seek out positive experiences and avoid negative ones. Our memory also treats pleasant emotions differently from unpleasant emotions. Pleasant emotions appear to fade more slowly from our memory than unpleasant emotions. This is not repression; people do remember negative events, they just remember them less negatively. Among those with mild depression, however, unpleasant and pleasant emotions tend to fade evenly.

Walker, W.R., Skowronski, J.J. & Thompson, C.P. 2003. Life Is Pleasant -- and Memory Helps to Keep It That Way! Review of General Psychology, 7(2),203-10.

http://www.eurekalert.org/pub_releases/2003-06/apa-rtg060203.php

Suppressing your expression of emotion affects your memory for the event

The way people go about controlling their reactions to emotional events affects their memory of the event. In a series of experiments designed to assess the effect of suppressing the expression of emotion, it was found that, when people were shown a video of an emotional event and instructed not to let their emotions show, they had poorer memory for what was said and done than did those people who were given no such instructions. However, when shown slides of people who had been injured, people in both groups were equally good at picking which in an array of subtly different versions of each slide had been shown earlier - but when prompted to recall information that had been presented verbally with each slide, those in the suppression group again remembered fewer details. People who were asked to adopt the neutral attitude of a medical profession however, performed better than the control group on nonverbal recall, indicating the regulation of emotions via reappraisal was not associated with any memory impairment. These experimental results were supported by a naturalistic study.

[607] Richards, J. M., & Gross J. J.
(2000).  Emotion regulation and memory: The cognitive costs of keeping one's cool..
Journal of Personality and Social Psychology. 79(3), 410 - 424.

http://www.sciencedaily.com/releases/2000/09/000913203335.htm

Mood

When mood affects memory

The effect of mood on memory depends on what questions are asked; only some aspects of memory are affected by incidental mood. For example, your memory of a restaurant's food won't be affected by the mood you were in when you ate it, but your memory of how much you enjoyed it will be. A new study shows that the effects of mood also depend on whether you had thought about that aspect during the experience — whether you had thought about how enjoyable the experience was at the time. In the study, people were shown a painting. Half of them were first put in a negative mood by reading and answering questions about an unpleasant subject. After looking at the painting, half were asked what they thought of it. Five days later, the participants were all asked how much they had liked the painting. While being in a negative mood had affected those who had evaluated the painting at the time, it did not affect those who had not made an evaluation at the time of presentation.

Pocheptsova, A. & Novemsky, N. 2009. When Do Incidental Mood Effects Last? Lay Beliefs versus Actual Effects. Journal of Consumer Research, Published online September 10, 2009

http://www.physorg.com/news172767544.html
http://www.eurekalert.org/pub_releases/2009-09/uocp-mmn092109.php

Perception affected by mood

An imaging study has revealed that when people were shown a composite image with a face surrounded by "place" images, such as a house, and asked to identify the gender of the face, those in whom a bad mood had been induced didn’t process the places in the background. However, those in a good mood took in both the focal and background images. These differences in perception were coupled with differences in activity in the parahippocampal place area. Increasing the amount of information is of course not necessarily a good thing, as it may result in more distraction.

[1054] Schmitz, T. W., De Rosa E., & Anderson A. K.
(2009).  Opposing Influences of Affective State Valence on Visual Cortical Encoding.
J. Neurosci.. 29(22), 7199 - 7207.

http://www.eurekalert.org/pub_releases/2009-06/uot-pww060309.php

Positive mood may not help in tasks requiring attention to detail

A series of experiments with different child age groups who had happy or sad moods induced with the aid of music and selected video clips before then being asked to undertake a task that required attention to detail has found that the children induced to feel a sad or neutral mood performed the task better than those induced to feel happy. Other research has found that a positive mood is beneficial in other situations, such as when a task calls for creative thinking.

[854] Schnall, S. [1], Jaswal V. K. [2], & Rowe C. [1]
(2008).  A hidden cost of happiness in children.
Developmental Science. 11, F25-F30 - F25-F30.

http://www.eurekalert.org/pub_releases/2008-06/uov-ssc053008.php

Omega-3 boosts grey matter

A study of 55 healthy adults has found that those who had high levels of long-chain omega-3 fatty acids had more gray matter in areas of the brain associated with emotional arousal and regulation — the bilateral anterior cingulate cortex, the right amygdala and the right hippocampus. Although this doesn’t mean omega-3 necessarily causes such changes, the finding does support a recent study that found higher levels of omega-3 were associated with a more positive outlook, and animal studies showing that increasing omega-3 intake leads to structural changes in the brain. Good sources of omega-3 fatty acids are walnuts, flax, and fatty fish such as salmon and sardines.

The findings were presented March 7 at the American Psychosomatic Society's Annual Meeting, in Budapest, Hungary.

http://www.sciencedaily.com/releases/2007/03/070307080827.htm
http://www.webmd.com/diet/news/20070307/omega-3-fatty-acids-may-boost-brain

Insight into the processes of 'positive' and 'negative' learners

An intriguing study of the electrical signals emanating from the brain has revealed two types of learners. A brainwave event called an "event-related potential" (ERP) is important in learning; a particular type of ERP called "error-related negativity" (ERN), is associated with activity in the anterior cingulate cortex. This region is activated during demanding cognitive tasks, and ERNs are typically more negative after participants make incorrect responses compared to correct choices. Unexpectedly, studies of this ERN found a difference between "positive" learners, who perform better at choosing the correct response than avoiding the wrong one, and "negative" learners, who learn better to avoid incorrect responses. The negative learners showed larger ERNs, suggesting that "these individuals are more affected by, and therefore learn more from, their errors.” Positive learners had larger ERNs when faced with high-conflict win/win decisions among two good options than during lose/lose decisions among two bad options, whereas negative learners showed the opposite pattern.

[818] Frank, M. J., Woroch B. S., & Curran T.
(2005).  Error-Related Negativity Predicts Reinforcement Learning and Conflict Biases.
Neuron. 47(4), 495 - 501.

http://www.eurekalert.org/pub_releases/2005-08/cp-iit081205.php

Positive emotions help people see big picture details

A study involving 89 students, who watched a video designed to induce either joy and laughter, anxiety, or no emotion, found that those who were in a positive mood had a far greater ability to recognize members of another race when briefly shown photos of individuals. In the absence of positive emotions, subjects recognized members of their own race 75% of the time but only recognized members of another race 65% of the time. Their ability to recognize members of their own race was unaffected by their emotional state.

[2551] Johnson, K. J., & Fredrickson B. L.
(2005).  “We All Look the Same to Me”.
Psychological Science. 16(11), 875 - 881.

http://www.eurekalert.org/pub_releases/2005-02/uom-pes020105.php

Mood affects eyewitness accuracy and reasoning

A new study suggests people in a negative mood provide more accurate eyewitness accounts than people in a positive mood state. Moreover, people in a positive mood showed poorer judgment and critical thinking skills than those in a negative mood. The researchers suggest that a negative mood state triggers more systematic and attentive, information processing, while good moods signal a benign, non-threatening environment where we don't need to be so vigilant.

[2550] Forgas, J. P., Laham S. M., & Vargas P. T.
(2005).  Mood effects on eyewitness memory: Affective influences on susceptibility to misinformation.
Journal of Experimental Social Psychology. 41(6), 574 - 588.

http://www.eurekalert.org/pub_releases/2004-08/uons-era082004.php

Excitement helps memory for unrelated events

We’ve long known that emotionally charged events are easier to remember than boring ones. New research suggests that the reason is the flood of emotion, not the personal meaningfulness of the event. Subjects asked to memorize a list of words did better if they subsequently watched a gory film of a bloody dental extraction, rather than a dull video on tooth brushing.

Nielson, K.A., Yee, D. & Erickson, K.I. 2002. Modulation of memory storage processes by post-training emotional arousal from a semantically unrelated source. Paper presented at the Society for Neuroscience annual meeting in Orlando, Florida, 4 November.

http://www.nature.com/nsu/021104/021104-5.html

Mood needs to be matched to cognitive task for best performance

An imaging study looked at the brain activity of 14 college-aged men and women as they performed difficult cognitive tasks requiring the active retention of information in working memory, after watching short, emotional videos, designed to elicit one of three emotional states: pleasant, neutral or anxious. It was found that mild anxiety improved performance on some tasks, but hurt performance on others. Being in a pleasant mood boosted some kinds of performance but impaired other kinds. A region of the prefrontal cortex was jointly influenced by a combination of mood state and cognitive task, but not by either one alone.

[227] Gray, J. R., Braver T. S., & Raichle M. E.
(2002).  Integration of emotion and cognition in the lateral prefrontal cortex.
Proceedings of the National Academy of Sciences of the United States of America. 99(6), 4115 - 4120.

http://www.eurekalert.org/pub_releases/2002-03/wuis-mlt031802.php

Brain study shows how surprises help us learn

Because they are hard to forget, surprises can help us learn. Now scientists have identified a part of the brain that may be involved in learning from surprises. A team led by Dr. Paul C. Fletcher at the University of Cambridge monitored the brain activity in a group of volunteers who were participating in a simulation exercise. The participants pretended to work at drug companies and were asked to predict whether a particular fictitious drug would trigger a particular fictitious syndrome. In the early phase of the study, when the participants were not familiar with the effects of the various drugs, imaging tests detected high levels of activity in this part of the brain. As the volunteers became familiar with the effects of the drugs, so that they were no longer surprised by the results, activity in the dorsolateral prefrontal cortex declined, but later in the study, this region became more active when the participants were surprised by unexpected responses.

[1329] Fletcher, P. C., Anderson J. M., Shanks D. R., Honey R., Carpenter T. A., Donovan T., et al.
(2001).  Responses of human frontal cortex to surprising events are predicted by formal associative learning theory.
Nat Neurosci. 4(10), 1043 - 1048.

Motivation & attitude

Confidence as important as IQ in exam success

I’ve talked repeatedly about the effects of self-belief on memory and cognition. One important area in which this is true is that of academic achievement. Evidence indicates that your perceived abilities matter, just as much? more than? your actual abilities. It has been assumed that self perceived abilities, self-confidence if you will, is a product mainly of nurture. Now a new twin study provides evidence that nurture / environment may only provide half the story; the other half may lie in the genes. The study involved 1966 pairs of identical twins and 1877 pairs of fraternal twins. The next step is to tease out which of these genes are related to IQ and which to personality variables.

[1080] Greven, C. U., Harlaar N., Kovas Y., Chamorro-Premuzic T., & Plomin R.
(2009).  More Than Just IQ: School Achievement Is Predicted by Self-Perceived Abilities—But for Genetic Rather Than Environmental Reasons.
Psychological Science. 20(6), 753 - 762.

http://www.newscientist.com/article/dn17187-confidence-as-important-as-iq-in-exam-success.html

Anticipation strengthens memory

An imaging study has revealed that the amygdala and the hippocampus become activated when a person is anticipating a difficult situation (some type of gruesome picture). Moreover, the higher the level of activation during this anticipation, the better the pictures were remembered two weeks later. The study demonstrates how expectancy can affect long-term memory formation, and suggests that the greater our anxiety about a situation, the better we’ll remember that situation. If it’s an unpleasant one, this will only reinforce the anxiety, setting up a vicious cycle. The study has important implications for the treatment of psychological conditions such as post-traumatic stress disorder and social anxiety.

[354] Mackiewicz, K. L., Sarinopoulos I., Cleven K. L., & Nitschke J. B.
(2006).  The effect of anticipation and the specificity of sex differences for amygdala and hippocampus function in emotional memory.
Proceedings of the National Academy of Sciences. 103(38), 14200 - 14205.

http://www.eurekalert.org/pub_releases/2006-09/uow-apa090106.php

Why motivation helps memory

An imaging study has identified the brain region involved in anticipating rewards — specific brain structures in the mesolimbic region involved in the processing of emotions — and revealed how this reward center promotes memory formation. Cues to high-reward scenes that were later remembered activated the reward areas of the mesolimbic region as well as the hippocampus. Anticipatory activation also suggests that the brain actually prepares in advance to filter incoming information rather than simply reacting to the world.

[1254] Adcock, A. R., Thangavel A., Whitfield-Gabrieli S., Knutson B., & Gabrieli J. D. E.
(2006).  Reward-Motivated Learning: Mesolimbic Activation Precedes Memory Formation.
Neuron. 50(3), 507 - 517.

http://www.eurekalert.org/pub_releases/2006-05/cp-tbm042706.php

Different brain regions for arousing and non-arousing words

An imaging study has found that words representing arousing events (e.g., “rape”, “slaughter”) activate cells in the amygdala, while nonarousing words (e.g., “sorrow”, “mourning”) activated cells in the prefrontal cortex. The hippocampus was active for both type of words. On average, people remembered more of the arousing words than the others, suggesting stress hormones, released as part of the response to emotionally arousing events, are responsible for enhancing memories of those events.

Kensinger, E.A. & Corkin, S. 2004. Two routes to emotional memory: Distinct neural processes for valence and arousal. PNAS, 101, 3310-3315. Published online before print February 23 2004, 10.1073/pnas.0306408101

http://www.eurekalert.org/pub_releases/2004-03/miot-mlu030104.php

 

Gender & age effects

When emotions involved, older adults may perform memory tasks better than young adults

A study involving 72 young adults (20-30 years old) and 72 older adults (60-75) has found that regulating emotions – such as reducing negative emotions or inhibiting unwanted thoughts – is a resource-demanding process that disrupts the ability of young adults to simultaneously or subsequently perform tasks, but doesn’t affect older adults. In the study, most of the participants watched a two-minute video designed to induce disgust, while the rest watched a neutral two-minute clip. Participants then played a computer memory game. Before playing 2 further memory games, those who had watched the disgusting video were instructed either to change their negative reaction into positive feelings as quickly as possible or to maintain the intensity of their negative reaction, or given no instructions. Those young adults who had been told to turn their disgust into positive feelings, performed significantly worse on the subsequent memory tasks, but older adults were not affected. The feelings of disgust in themselves did not affect performance in either group. It’s speculated that older adults’ greater experience allows them to regulate their emotions without cognitive effort.

[200] Scheibe, S., & Blanchard-Fields F.
(2009).  Effects of regulating emotions on cognitive performance: what is costly for young adults is not so costly for older adults.
Psychology and Aging. 24(1), 217 - 223.

http://www.eurekalert.org/pub_releases/2009-03/giot-oac030409.php

Aging brains allow negative memories to fade

Another study has found that older adults (average age 70) remember fewer negative images than younger adults (average age 24), and that this has to do with differences in brain activity. When shown negative images, the older participants had reduced interactions between the amygdala and the hippocampus, and increased interactions between the amygdala and the dorsolateral frontal cortex. It seems that the older participants were using thinking rather than feeling processes to store these emotional memories, sacrificing information for emotional stability. The findings are consistent with earlier research showing that healthy seniors are able to regulate emotion better than younger people.

[680] St Jacques, P. L., Dolcos F., & Cabeza R.
(2009).  Effects of aging on functional connectivity of the amygdala for subsequent memory of negative pictures: a network analysis of functional magnetic resonance imaging data.
Psychological Science: A Journal of the American Psychological Society / APS. 20(1), 74 - 84.

http://www.eurekalert.org/pub_releases/2008-12/uoaf-aba121608.php
http://www.eurekalert.org/pub_releases/2008-12/dumc-oay121508.php

Emotions help memory, at the cost of other memories

Do we remember emotionally charged events better? Maybe — but at a price. A new study presented volunteers with lists of neutral words with one disturbing noun, such as murder or scream, embedded. As expected, the emotional words were much better remembered than the neutral words. More interestingly, the poorest memory occurred for neutral words that were presented immediately before the disturbing words. The effect was greater for women — women forgot those words twice as often as men.

[214] Strange, B. A., Hurlemann R., & Dolan R. J.
(2003).  An emotion-induced retrograde amnesia in humans is amygdala- and beta-adrenergic-dependent.
Proceedings of the National Academy of Sciences of the United States of America. 100(23), 13626 - 13631.

http://www.sciencenews.org/20031108/fob5.asp

Why women better remember emotional memories

A new brain imaging study reveals gender differences in the encoding of emotional memories. We have long known that women are better at remembering emotional memories, now we can see that the sexes tend to encode emotional experiences in different parts of the brain. In women, it seems that evaluation of emotional experience and encoding of the memory is much more tightly integrated.

[807] Canli, T., Desmond J. E., Zhao Z., & Gabrieli J. D. E.
(2002).  Sex differences in the neural basis of emotional memories.
Proceedings of the National Academy of Sciences of the United States of America. 99(16), 10789 - 10794.

http://www.newscientist.com/news/news.jsp?id=ns99992576

Older adults better at forgetting negative images

It seems that this general tendency, to remember the good, and let the bad fade, gets stronger as we age. Following recent research suggesting that older people tend to regulate their emotions more effectively than younger people, by maintaining positive feelings and lowering negative feelings, researchers examined age differences in recall of positive, negative and neutral images of people, animals, nature scenes and inanimate objects. The first study tested 144 participants aged 18-29, 41-53 and 65-80. Older adults recalled fewer negative images relative to positive and neutral images. For the older adults, recognition memory also decreased for negative pictures. As a result, the younger adults remembered the negative pictures better. Preliminary brain research suggests that in older adults, the amygdala is activated equally to positive and negative images, whereas in younger adults, it is activated more to negative images. This suggests that older adults encode less information about negative images, which in turn would diminish recall.

[343] Charles, S T., Mather M., & Carstensen L. L.
(2003).  Aging and Emotional Memory: The Forgettable Nature of Negative Images for Older Adults.
Journal of Experimental Psychology: General. 132(2), 310 - 324.

http://www.apa.org/releases/aging_memory.html

Gender & race stereotypes

Neurology

Nasal spray boosts consolidation of emotional memory

A study in which 17 healthy young men were given a nasal spray of either interleukin-6 or a placebo after reading a short story (emotional on one occasion; neutral on the other) before going to bed, has found that those given the immune system molecule showed improved memory for emotional text (but not other kinds of material). Interleukin-6 is involved in inflammatory responses, but recently has also been implicated in memory consolidation during sleep. This finding supports that role, and demonstrates an interaction between the immune system and the central nervous system.

[811] Benedict, C., Scheller J., Rose-John S., Born J., & Marshall L.
(2009).  Enhancing influence of intranasal interleukin-6 on slow-wave activity and memory consolidation during sleep.
FASEB J.. 23(10), 3629 - 3636.

http://www.sciencedaily.com/releases/2009/10/091001091752.htm

Sleep selectively preserves emotional memories

It’s now generally accepted that sleep plays an important role in consolidating procedural (skill) memories, but the position regarding other types of memory has been less clear.  A new study has found that sleep had an effect on emotional aspects of a memory. The study involved showing 88 students neutral scenes (such as a car parked on a street in front of shops) or negative scenes (a badly crashed car parked on a similar street). They were then tested for their memories of both the central objects in the pictures and the backgrounds in the scenes, either after 12 daytime hours, or 12 night-time hours, or 30 minutes after viewing the images, in either the morning or evening.  Those tested after 12 daytime hours largely forgot the entire negative scene, forgetting both the central objects and the backgrounds equally. But those tested after a night’s sleep remembered the emotional item (e.g., the smashed car) as well as those who were tested only 30 minutes later. Their memory of the neutral background was however, as bad as the daytime group. The findings are consistent with the view that the individual components of emotional memory become 'unbound' during sleep, enabling the brain to selectively preserve only that information it considers important.

[875] Payne, J. D., Stickgold R., Swanberg K., & Kensinger E. A.
(2008).  Sleep preferentially enhances memory for emotional components of scenes.
Psychological Science: A Journal of the American Psychological Society / APS. 19(8), 781 - 788.

http://www.physorg.com/news137908693.html
http://www.eurekalert.org/pub_releases/2008-08/bidm-sft081308.php

Why emotion enhances memory

We know that emotion can increase the memorability of events, but we haven’t known exactly why it does so. Now a new study reveals that during emotional arousal, the stress hormone norepinephrine makes synapses dramatically more sensitive by increasing the number of GluR1 receptors.

[423] Hu, H., Real E., Takamiya K., Kang M-G., Ledoux J., Huganir R. L., et al.
(2007).  Emotion Enhances Learning via Norepinephrine Regulation of AMPA-Receptor Trafficking.
Cell. 131(1), 160 - 173.

http://www.eurekalert.org/pub_releases/2007-10/jhmi-wem100407.php
http://www.eurekalert.org/pub_releases/2007-10/cp-hec100107.php
http://www.brainatlas.org/aba/2007/071018/full/aba1787.shtml

How emotions interfere with memory

We know emotion can interfere with cognitive processes. Now an imaging study adds to our understanding of how that occurs. Emotional images evoked strong activity in typical emotional processing regions (amygdala and ventrolateral prefrontal cortex) while simultaneously deactivating regions involved in memory processing (dorsolateral prefrontal cortex and lateral parietal cortex). The researchers also found individual differences among the subjects in their response to the images. People who showed greater activity in a brain region associated with the inhibition of response to emotional stimuli rated the emotional distracters as less distracting.

[270] Dolcos, F., & McCarthy G.
(2006).  Brain Systems Mediating Cognitive Interference by Emotional Distraction.
J. Neurosci.. 26(7), 2072 - 2079.

http://www.eurekalert.org/pub_releases/2006-02/dumc-he021506.php

Different aspects of attention located in different parts of the brain

We all know attention is important, but we’ve never been sure exactly what it is. Recent research suggests there’s good reason for this – attention appears to be multi-faceted, far less simple than originally conceived. Patients with specific lesions in the frontal lobes and other parts of the brain have provided evidence that different types of attentional problems are associated with injuries in different parts of the brain, suggesting that attention is not, as has been thought, a global process. The researchers have found evidence for at least three distinct processes, each located in different parts of the frontal lobes. These are: (1) a system that helps us maintain a general state of readiness to respond, in the superior medial frontal regions; (2) a system that sets our threshold for responding to an external stimulus, in the left dorsolateral region; and (3) a system that helps us selectively attend to appropriate stimuli, in the right dorsolateral region.

[260] Stuss, D. T., Binns M. A., Murphy K. J., & Alexander M. P.
(2002).  Dissociations within the anterior attentional system: effects of task complexity and irrelevant information on reaction time speed and accuracy.
Neuropsychology. 16(4), 500 - 513.

http://www.eurekalert.org/pub_releases/2002-10/apa-pda100702.php

How emotions interfere with staying focused

In a new imaging study, Duke University researchers have shown how emotional stimuli and "attentional functions" like driving move in parallel streams through the brain before being integrated in a specific part of the brain's prefrontal cortex (the anterior cingulate, which is located between the right and left halves). Emotional stimuli are thus more likely than simple distractions to interfere with a person's efforts to focus on a task such as driving. These findings may help us understand the neural dynamics underlying emotional distractibility on attentional tasks in affective disorders.

[835] Yamasaki, H., LaBar K. S., & McCarthy G.
(2002).  Dissociable prefrontal brain systems for attention and emotion.
Proceedings of the National Academy of Sciences of the United States of America. 99(17), 11447 - 11451.

www.pnas.org/cgi/doi/10.1073/pnas.182176499
http://www.pnas.org/cgi/content/abstract/99/17/11447

Cerebellum implicated in remembering emotions

The part of the brain known as the cerebellum has been most closely associated with motor coordination skills. Experiments with rats suggest that it may also be involved in remembering strong emotions, in particular, in the consolidation of long-term memories of fear.

[763] Sacchetti, B., Baldi E., Lorenzini C A., & Bucherelli C.
(2002).  Cerebellar role in fear-conditioning consolidation.
Proceedings of the National Academy of Sciences of the United States of America. 99(12), 8406 - 8411.

http://www.pnas.org/cgi/content/abstract/112660399v1
http://news.bmn.com/jscan/biology?uid=18768

Amygdala may be critical for allowing perception of emotionally significant events despite inattention

We choose what to pay attention to, what to remember. We give more weight to some things than others. Our perceptions and memories of events are influenced by our preconceptions, and by our moods. Researchers at Yale and New York University have recently published research indicating that the part of the brain known as the amygdala is responsible for the influence of emotion on perception. This builds on previous research showing that the amygdala is critically involved in computing the emotional significance of events. The amygdala is connected to those brain regions dealing with sensory experiences, and the theory that these connections allow the amygdala to influence early perceptual processing is supported by this research. Dr. Anderson suggests that “the amygdala appears to be critical for the emotional tuning of perceptual experience, allowing perception of emotionally significant events to occur despite inattention.”

[968] Anderson, A. K., & Phelps E. A.
(2001).  Lesions of the human amygdala impair enhanced perception of emotionally salient events.
Nature. 411(6835), 305 - 309.

http://www.eurekalert.org/pub_releases/2001-05/NYU-Infr-1605101.php

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