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

Hypnosis study sheds insight on amnesia

An intriguing study investigating brain activity of hypnotically induced forgetting may shed light on amnesia. Researchers showed volunteers a documentary depicting a day in the life of a young woman, followed a week later with a brain scan while they were put into a hypnotic state. They were given a posthypnotic suggestion to forget the movie, and a reversibility cue that would restore the memory. When their recall of the movie was later tested, those susceptible to posthypnotic amnesia showed reduced recall. Brain scans revealed different brain activity patterns between those susceptible and those who were not. For the susceptible, activity in some brain regions was suppressed during memory suppression, while activity in other regions increased. But when the posthypnotic suggestion was reversed, the susceptible group showed recovery of activity in suppressed regions. The findings suggest that suppression was exerted at early stages of the retrieval process, specifically, an executive pre-retrieval monitoring process that produces an early decision on whether to proceed or not on retrieval. The researchers suggest that some forms of amnesia may be a consequence of this ‘preretrieval memory abort’ mechanism.

Mendelsohn, A., Chalamish, Y., Solomonovich, A. & Dudai, Y. 2008. Mesmerizing Memories: Brain Substrates of Episodic Memory Suppression in Posthypnotic Amnesia. Neuron, 57, 159-170.

Statins associated with rare cases of temporary amnesia

Two recent studies have documented cases of amnesia and other nervous-system side effects after taking statins, the cholesterol-lowering drugs being prescribed to millions of people at risk of heart disease. It is emphasized that this is a rare problem, but given the vast numbers of people taking statins, it might still add up to a significant number of problems.

[2389] Wagstaff, L. R., Mitton M. W., Arvik B ML., & Doraiswamy M. P.
(2003).  Statin-Associated Memory Loss: Analysis of 60 Case Reports and Review of the Literature.
Pharmacotherapy. 23(7), 871 - 880.


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

Relearning a forgotten language is easier for those under 40

A small study involving 7 native English speakers who had learned either Hindi or Zulu as children when living abroad, but now had no memory of the neglected language, found that the three who were under 40 could relearn certain phonemes that are difficult for native English speakers to recognize, but those over 40, like those who had never been exposed to the language in childhood, could not. The amount of experience of exposure in childhood ranged from 4 to 10 years, and it’s especially notable that the 47-year old individual who had 10 years exposure, having become almost fluent, still could not recover the ability to distinguish these difficult sounds. It should also be noted that where the ability was recovered (and recovered almost to native ability), it took about 15-20 training sessions. The findings point to the value of early foreign language learning.

Bowers, J.S., Mattys, S.L. & Gage, S.H. 2009. Preserved Implicit Knowledge of a Forgotten Childhood Language. Psychological Science, 20 (9), 1064–1069.

Forgotten memories still there

In an imaging study in which 16 college students were shown a list of words, asked to say each word backwards, think of how it could be used, and imagine how an artist would draw it, then shown the list again 20 minutes later and asked to remember what they could of each word, brain activity showed that recollection reinstated the original pattern of activity, and its strength correlated with the strength of the memory. Moreover, even when the student had no conscious memory, the pattern was still there, although weak. Follow-up studies will explore the degradation over time.

Johnson, J.D. et al. 2009. Recollection, Familiarity, and Cortical Reinstatement: A Multivoxel Pattern Analysis. Neuron, 63 (5), 697-708.

New insights into memory without conscious awareness

An imaging study in which participants were shown a previously studied scene along with three previously studied faces and asked to identify the face that had been paired with that scene earlier has found that hippocampal activity was closely tied to participants' tendency to view the associated face, even when they failed to identify it. Activity in the lateral prefrontal cortex, an area required for decision making, was sensitive to whether or not participants had responded correctly and communication between the prefrontal cortex and the hippocampus was increased during correct, but not incorrect, trials. The findings suggest that conscious memory may depend on interactions between the hippocampus and the prefrontal cortex.

Hannula, D.E. & Ranganath, C. 2009. The Eyes Have It: Hippocampal Activity Predicts Expression of Memory in Eye Movements. Neuron, 63 (5), 592-599.

How we forget over the short term

Information in short-term memory is rapidly forgotten once attention is diverted, but why? Is it because memory traces decay in the absence of attention? Or is it because older traces interfere with new traces? In a study in which volunteers were shown a string of 3 letters, then told to count backwards for 4, 8, 12, or 16 seconds, before recalling the letters, it was found that those who counted backwards for the longest time were better able to recall the letters than those who counted backwards for shorter times. This suggests that temporal confusability, not decay, is the main culprit in short-term forgetting. The finding is consistent with research indicating that interference is more important than decay in long-term forgetting as well.

Unsworth, N., Heitz, R.P. & Parks, N.A. 2008. The Importance of Temporal Distinctiveness for Forgetting Over the Short Term. Psychological Science, 19 (11), 1078-1081.

Forgotten but not gone

We all know it’s easier to re-learn something than learn it for the first time. But why? When we learn, as we know, a neuron makes new connections with other neurons, and these connections are made through synapses. If that connection breaks down, we forget. A new study sheds light on what happens when we re-learn something we thought was forgotten. It appears that in the case of information (synaptic connections) that isn’t needed any more, the synapses are disabled, not destroyed. When needed again, they just need to be reactivated.

Hofer, S.B. et al. 2008. Experience leaves a lasting structural trace in cortical circuits. Nature, Published online November 12, 2008

A new perspective on forgetting

A new mathematical model may shed light on forgetting. The model has found that "free-lunch learning" (the way in which forgotten material is called back to mind when we relearn some part of it — as when a few words in a foreign language we learned at school brings back many other words) occurs when forgetting was induced by random fluctuations in the strength of synaptic connections (‘synaptic drift'). But when forgetting is induced by progressive decay in synaptic strength (which is how forgetting has traditionally been thought of), then "negative free-lunch learning" (where relearning parts of forgotten associations decreases the recall of associated knowledge) occurs. This suggests that forgetting occurs because of random drift rather than a decay in the strength of synaptic connections.

Stone, J.V. & Jupp P.E. 2008. Falling towards Forgetfulness: Synaptic Decay Prevents Spontaneous Recovery of Memory. PLoS Computational Biology, 4(8), e1000143. Full text available at

New research shows why too much memory may be a bad thing

People who are able to easily and accurately recall historical dates or long-ago events may have a harder time with word recall or remembering the day's current events. A mouse study reveals why. Neurogenesis has been thought of as a wholly good thing — having more neurons is surely a good thing — but now a mouse study has found that stopping neurogenesis in the hippocampus improved working memory. Working memory is highly sensitive to interference from information previously stored in memory, so it may be that having too much information may hinder performing everyday working memory tasks.

Saxe, M.D. et al. 2007. Paradoxical influence of hippocampal neurogenesis on working memory. Proceedings of the National Academy of Sciences, 104 (11), 4642-4646.
Full text is available at

More insight into why we forget

Increasingly researchers have come to believe interference is far more important for forgetting than the traditional notion of decay over time. A technique called "transcranial magnetic stimulation" (TMS) has now revealed that an area within the prefrontal cortex called the left inferior frontal gyrus, known to be active when volunteers take memory tests while confronting interference, is essential for blocking interference.

Feredoes, E., Tononi, G. & Postle, B.R. 2006. Direct evidence for a prefrontal contribution to the control of proactive interference in verbal working memory. Proceedings of the National Academy of Sciences, 103 (51), 19530-19534.

Memories are harder to forget than recently thought

Previous rodent studies have shown that the process of encoding a memory can be blocked by the use of a protein synthesis inhibitor called anisomycin ( Experiments with anisomycin helped lead to the acceptance of a theory in which a learned behavior is consolidated into a stored form and that then enters a 'labile' - or adaptable - state when it is recalled. According to these previous studies, the act of putting a labile memory back into storage involves a reconsolidation process identical to the one used to store the memory initially. Indeed, experiments showed that anisomycin could make a mouse forget a memory if it were given anisomycin directly after remembering an event. In a new study, however, researchers have showed that disruption of a "re-remembered" memory was not permanent. Mice demonstrated that they could remember the original learned behavior 21 days later. This research thus casts doubt on the concept of “reconsolidation”, or at least demonstrates that we still have much to learn about this process.

Lattal, K.M. & Abel, T. 2004. Behavioral impairments caused by injections of the protein synthesis inhibitor anisomycin after contextual retrieval reverse with time. PNAS, 101, 4667-4672.

More evidence for active forgetting

In an imaging study involving 24 people aged 19 to 31, participants were given pairs of words and told to remember some of the matched pairs but forget others. Trying to shut out memory appeared more demanding than remembering, in that some areas of the brain were significantly more when trying to suppress memory. Both the prefrontal cortex and the hippocampus were active. Those whose prefrontal cortex and hippocampus were most active during this time were most successful at suppressing memory.

Anderson, M.C., Ochsner, K.N., Kuhl, B., Cooper, J., Robertson, E., Gabrieli, S.W., Glover, G.H. & Gabrieli, J.D.E. 2004. Neural Systems Underlying the Suppression of Unwanted Memories. Science, 303 (5655), 232-235.

You may not be able to recall it, but it influences you anyway

“Forgetting” doesn’t mean the memory is erased from your brain. “Forgotten” information may in fact influence you more than it would if it hadn’t been forgotten — because you’re unaware of the influence. This somewhat alarming possibility has been raised by a recent study in which college students studied lists of nonfamous and famous names. Some participants were told to remember the nonfamous names, while the others were told to forget them. Later, both groups were asked to judge whether or not a name was famous from a mixed list of famous and nonfamous names. Those who were told to forget misidentified more nonfamous names as famous than those who had been told to remember.
Such a judgment is of course made on the basis of the familiarity of the name. It is exposure to an item that affects its familiarity – not whether or not you consciously remember it. By telling the participants to “forget” what they’d seen, the experimenters were removing the participants’ awareness of the source of the familiarity, not the familiarity itself.

Bjork, E.L. & Bjork, R.A. 2003. Intentional Forgetting Can Increase, Not Decrease, Residual Influences of To-Be-Forgotten Information. Journal of Experimental Psychology: Learning, Memory, and Cognition, 29 (4), 524–531.

Failing recall not an inevitable consequence of aging

New research suggests age-related cognitive decay may not be inevitable. Tests of 36 adults with an average age of 75 years found that about one out of four had managed to avoid memory decline. Those adults who still had high frontal lobe function had memory skills “every bit as sharp as a group of college students in their early 20s." (But note that most of those older adults who participated were highly educated – some were retired academics). The study also found that this frontal lobe decline so common in older adults is associated with an increased susceptibility to false memories – hence the difficulty often experienced by older people in recalling whether they took a scheduled dose of medication.

The research was presented on August 8 at the American Psychological Association meeting in Toronto.

Selective erasure of memories one step closer

It is now believed that memories become “labile” (able to be changed) every time they are reactivated. If so, it would seem that we could, by re-activating a memory, “erase” it – even though the memory is very old. Researchers have, however, had mixed success in achieving this. A new report suggests why. Any memory is made up of a number of different associations, but only one association will be “dominant” (will determine our reaction). It is this dominant association that is susceptible to change, and thus, to erasure.

Eisenberg, M., Kobilo, T., Berman, D.E. & Dudai, Y. 2003. Stability of Retrieved Memory: Inverse Correlation with Trace Dominance. Science, 301 (5636), 1102-1104.

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.

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), 310-24.

Memories may be hard to find when thalamus fails to synchronize rhythms

Memory codes - the representation of an object or experience in memory - are patterns of connected neurons. The neurons that are linked are not necessarily in the same region of the brain. Exciting new research has measured the electrical rhythms that parts of the brain use to communicate with each other and found that the thalamus regulates these rhythms. "Memory appears to be a constructive process in combining the features of the items to be remembered rather than simply remembering each object as a whole form. The thalamus seems to direct or modulate the brain's activity so that the regions needed for memory are connected." The authors suggest that tips of the tongue experiences (when only part of a memory is recalled) may occur when the rhythms don't synchronize with the regions properly.

Slotnick, S.D., Moo, L.R., Kraut, M.A., Lesser, R.P. & Hart, J. Jr. 2002. Interactions between thalamic and cortical rhythms during semantic memory recall in human. Proc. Natl. Acad. Sci. U.S.A., 99, 6440-6443.


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

Overweight and obese elderly have smaller brains

Analysis of brain scans from 94 people in their 70s who were still "cognitively normal" five years after the scan has revealed that people with higher body mass indexes had smaller brains on average, with the frontal and temporal lobes particularly affected (specifically, in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus, in obese people, and in the basal ganglia and corona radiate of the overweight). The brains of the 51 overweight people were, on average, 6% smaller than those of the normal-weight participants, and those of the 14 obese people were 8% smaller. To put it in more comprehensible, and dramatic terms: "The brains of overweight people looked eight years older than the brains of those who were lean, and 16 years older in obese people." However, overall brain volume did not differ between overweight and obese persons. As yet unpublished research by the same researchers indicates that exercise protects these same brain regions: "The most strenuous kind of exercise can save about the same amount of brain tissue that is lost in the obese."

[733] Thompson, P. M., Raji C. A., Ho A. J., Parikshak N. N., Becker J. T., Lopez O. L., et al.
(2010).  Brain structure and obesity.
Human Brain Mapping. 31(3), 353 - 364.

Obesity surgery can lead to memory loss

A review of the literature has found that weight loss surgery such as gastric bypass surgery, can lead to a vitamin deficiency that can cause memory loss and confusion, inability to coordinate movement, and other problems. Wernicke encephalopathy affects the brain and nervous system when the body doesn’t get enough vitamin B1 (thiamine). The study found that the syndrome occurs most often in people who have frequent vomiting after the surgery, and usually occurs within one to three months after the surgery.

Singh, S. & Kumar, A. 2007. Wernicke encephalopathy after obesity surgery: A systematic review. Neurology, 68, 807-811.

High BMI tied to poorer cognitive function in middle-aged adults

A study of 2,223 healthy French men and women aged 32—62 found that a higher body mass index (BMI) was associated with lower scores on a word-recall task.

[823] Cournot, M., Marquie J. C., Ansiau D., Martinaud C., Fonds H., Ferrieres J., et al.
(2006).  Relation between body mass index and cognitive function in healthy middle-aged men and women.
Neurology. 67(7), 1208 - 1214.

Morbid obesity in toddlers linked to low IQ

A study of 18 children and adults with early-onset morbid obesity (they weighed at least 150% of their ideal body weight before they were 4), 19 children and adults with Prader-Willi syndrome, and 24 of their normal-weight siblings, has revealed a link between morbid obesity in toddlers and lower IQ scores, cognitive delays and brain lesions similar to those seen in Alzheimer's disease patients. The links between cognitive impairments and Prader-Willi syndrome (a genetic disorder that causes people to eat nonstop and become morbidly obese at a very young age if not supervised) are well-established. But researchers were surprised to find patients with early-onset morbid obesity had an average IQ of 77, compared to an average of 63 for Prader-Willi patients and an average of 106 for the control group of siblings. Scans also revealed white-matter lesions on the brains of many of the Prader-Willi and early-onset morbidly obese patients.

[962] Sahoo, T., Beaudet A. L., Driscoll D. J., Miller J., Kranzler J., Liu Y., et al.
(2006).  Neurocognitive findings in Prader-Willi syndrome and early-onset morbid obesity.
The Journal of Pediatrics. 149(2), 192 - 198.

Fat hormone linked to learning and memory

A new study reveals why obese patients who have diabetes also may have problems with their long-term memory. Leptin — the so-called ‘fat’ hormone — doesn't cross into the brain to help regulate appetite in obese people. Leptin also acts in the hippocampus, suggesting that leptin plays a role in learning and memory. The new study supports this by demonstrating that mice navigated a maze better after they received leptin. Moreover, mice with elevated levels of amyloid-beta plaques (characteristic of Alzheimer's) were particularly sensitive to leptin.

[2400] Farr, S. A., Banks W. A., & Morley J. E.
(2006).  Effects of leptin on memory processing.
Peptides. 27(6), 1420 - 1425.

Attention Problems

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

Binge drinking affects attention and working memory in young university students

A Spanish study of 95 first-year university students, 42 of them binge drinkers, has found that those who engaged in binge drinking required greater attentional processing during a visual working memory task in order to carry it out correctly. They also had difficulties differentiating between relevant and irrelevant stimuli. Binge drinkers are defined as males who drink five or more standard alcohol drinks, and females who drink four or more, on one occasion and within a two-hour interval. Some 40% of university students in the U.S. are considered binge drinkers.

 [231] Crego, A., Holguín S R., Parada M., Mota N., Corral M., & Cadaveira F.
(2009).  Binge drinking affects attentional and visual working memory processing in young university students.
Alcoholism, Clinical and Experimental Research. 33(11), 1870 - 1879.

Short stressful events may improve working memory

We know that chronic stress has a detrimental effect on learning and memory, but a new rat study shows how acute stress (a short, sharp event) can produce a beneficial effect. The rats, trained to a level of 60-70% accuracy on a maze, were put through a 20-minute forced swim before being run through the maze again. Those who experienced this stressful event were better at running the maze 4 hours later, and a day later, than those not forced through the stressful event. It appears that the stress hormone corticosterone (cortisol in humans) increases transmission of the neurotransmitter glutamate in the prefrontal cortex and improves working memory. It also appears that chronic stress suppresses the transmission of glutamate in the prefrontal cortex of male rodents, while estrogen receptors in female rodents make them more resilient to chronic stress than male rats.

[1157] Yuen, E. Y., Liu W., Karatsoreos I. N., Feng J., McEwen B. S., & Yan Z.
(2009).  Acute stress enhances glutamatergic transmission in prefrontal cortex and facilitates working memory.
Proceedings of the National Academy of Sciences of the United States of America. 106(33), 14075 - 14079.

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.

Inconsistent processing speed among children with ADHD

A new analytical technique has revealed that the problem with children with ADHD is not so much that they are slower at responding to tasks, but rather that their response is inconsistent. The study of 25 children with ADHD and 24 typically developing peers found that on a task in which a number on one screen needed to be mentally added to another number shown on a second screen, those with ADHD were much less consistent in their response times, although the responses they did give were just as accurate. Higher levels of hyperactivity and restlessness or impulsivity (as measured by parent survey) correlated with more slower reaction times. The finding supports the idea that what underlies impaired working memory is a problem in how consistently a child with ADHD can respond during a working memory task.

[911] Buzy, W. M., Medoff D. R., & Schweitzer J. B.
(2009).  Intra-Individual Variability Among Children with ADHD - on a Working Memory Task: An Ex-Gaussian Approach.
Child Neuropsychology. 15(5), 441 - 441.

Hyperactivity enables children with ADHD to stay alert

A study of 12 8- to 12-year-old boys with ADHD, and 11 of those without, has found that activity levels of those with ADHD increased significantly whenever they had to perform a task that placed demands on their working memory. In a highly stimulating environment where little working memory is required (such as watching a Star Wars video), those with ADHD kept just as still as their normal peers. It’s suggested that movement helps them stay alert enough to complete challenging tasks, and therefore trying to limit their activity (when non-destructive) is counterproductive. Providing written instructions, simplifying multi-step directions, and using poster checklists are all strategies that can be used to help children with ADHD learn without overwhelming their working memories.

[734] Rapport, M., Bolden J., Kofler M., Sarver D., Raiker J., & Alderson R.
(2009).  Hyperactivity in Boys with Attention-Deficit/Hyperactivity Disorder (ADHD): A Ubiquitous Core Symptom or Manifestation of Working Memory Deficits?.
Journal of Abnormal Child Psychology. 37(4), 521 - 534.

Poverty can physically impair brain, reducing children's ability to learn

We know that stress affects learning and memory, and there is considerable evidence confirming the commonsense intuition that low-income families are under a lot of stress. Now a long-term study involving 195 children from rural households above and below the poverty line has found that children who lived in impoverished environments for longer periods of time during childhood showed higher stress scores and suffered greater impairments in working memory at 17. Those who spent their entire childhood in poverty scored about 20% lower on working memory tests at 17 than those who were never poor.

[461] Evans, G. W., & Schamberg M. A.
(2009).  Childhood poverty, chronic stress, and adult working memory.
Proceedings of the National Academy of Sciences. 106(16), 6545 - 6549.

Full text available at

New research shows why too much memory may be a bad thing

People who are able to easily and accurately recall historical dates or long-ago events may have a harder time with word recall or remembering the day's current events. A mouse study reveals why. Neurogenesis has been thought of as a wholly good thing — having more neurons is surely a good thing — but now a mouse study has found that stopping neurogenesis in the hippocampus improved working memory. Working memory is highly sensitive to interference from information previously stored in memory, so it may be that having too much information may hinder performing everyday working memory tasks.

[635] Saxe, M. D., Malleret G., Vronskaya S., Mendez I., Garcia D. A., Sofroniew M. V., et al.
(2007).  Paradoxical influence of hippocampal neurogenesis on working memory.
Proceedings of the National Academy of Sciences. 104(11), 4642 - 4646.

Full text is available at

Implicit stereotypes and gender identification may affect female math performance

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.

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.

Highly accomplished people more prone to failure than others when under stress

One important difference between those who do well academically and those who don’t is often working memory capacity. Those with a high working memory capacity find it easier to read and understand and reason, than those with a smaller capacity. However, a new study suggests there is a downside. Such people tend to heavily rely on their abundant supply of working memory and are therefore disadvantaged when challenged to solve difficult problems, such as mathematical ones, under pressure — because the distraction caused by stress consumes their working memory. They then fall back on the less accurate short-cuts that people with less adequate supplies of working memory tend to use, such as guessing and estimation. Such methods are not made any worse by working under pressure. In the study involving 100 undergraduates, performance of students with strong working memory declined to the same level as those with more limited working memory, when the students were put under pressure. Those with more limited working memory performed as well under added pressure as they did without the stress.

The findings were presented February 17 at the annual meeting of the American Association for the Advancement of Science.

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.

Anxiety adversely affects those who are most likely to succeed at exams

It has been thought that pressure harms performance on cognitive skills such as mathematical problem-solving by reducing the working memory capacity available for skill execution. However, a new study of 93 students has found that this applies only to those high in working memory. It appears that the advantage of a high working memory capacity disappears when that attention capacity is compromised by anxiety.

[355] Beilock, S. L., & Carr T. H.
(2005).  When high-powered people fail: working memory and "choking under pressure" in math.
Psychological Science: A Journal of the American Psychological Society / APS. 16(2), 101 - 105.

Memory-enhancing drugs for elderly may impair working memory and other executive functions

Drugs that increase the activity of an enzyme called protein kinase A improve long-term memory in aged mice and have been proposed as memory-enhancing drugs for elderly humans. However, the type of memory improved by this activity occurs principally in the hippocampus. A new study suggests that increased activity of this enzyme has a deleterious effect on working memory (which principally involves the prefrontal cortex). In other words, a drug that helps you remember a recent event may worsen your ability to remember what you’re about to do (to take an example).

[1404] Ramos, B. P., Birnbaum S. G., Lindenmayer I., Newton S. S., Duman R. S., & Arnsten A. F. T.
(2003).  Dysregulation of protein kinase a signaling in the aged prefrontal cortex: new strategy for treating age-related cognitive decline.
Neuron. 40(4), 835 - 845.

Sleep deprivation affects working memory

A recent study investigated the working memory capacities of individuals who were sleep-deprived. For nine days, 7 of the 12 participants slept four hours each night, and 5 slept for eight hours. Each morning, participants completed a computer task to measure how quickly they could access a list of numbers they had been asked to memorize. The list could be one, three, or five items long. Then participants were presented with a series of single digits and asked to answer "yes" or "no" to indicate whether each digit was one they had memorized. Those who slept eight hours a night steadily increased their working memory efficiency on this task, but those who slept only four hours a night failed to show any improvement in memory efficiency. Motor skill did not change across days for either group of participants.

The findings were presented at the Society for Neuroscience 2003 annual  conference.

Cognitive impairment following bypass surgery may last longer than thought

More support for a link between cardiopulmonary bypass surgery and cognitive impairment comes from a new study. In particular, it seems, that attention may be most affected. The study also found evidence of longer-lasting cognitive decline than previously thought. Bypass patients also demonstrated poorer cognitive performance before the surgery, and it is now being suggested that it may be the disease itself that is the major problem, rather than the surgery itself. This is consistent with recent research connecting cardiovascular risk factors with risk factors for cognitive decline.

[716] Keith, J. R., Puente A. E., Malcolmson K. L., Tartt S., Coleman A. E., & Marks H. F.
(2002).  Assessing postoperative cognitive change after cardiopulmonary bypass surgery.
Neuropsychology. 16(3), 411 - 421.

Cocaine may permanently damage learning abilities in developing fetuses

Two recent studies investigating the effect of pre-natal exposure to cocaine in rats suggest that children exposed to cocaine while in the womb may have permanent changes to the part of the brain that helps control attention and memory, leading to learning deficits and symptoms that are very much like attention deficit hyperactivity disorder.

[1270] Morrow, B. A., Elsworth J. D., & Roth R. H.
(2002).  Male rats exposed to cocaine in utero demonstrate elevated expression of Fos in the prefrontal cortex in response to environment.
Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology. 26(3), 275 - 285.

[264] Morrow, B. A., Elsworth J. D., & Roth R. H.
(2002).  Prenatal cocaine exposure disrupts non-spatial, short-term memory in adolescent and adult male rats.
Behavioural Brain Research. 129(1-2), 217 - 223.

tags problems: 

Visual Impairment

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

Age-related eye disease associated with cognitive impairment

Age-related macular degeneration (AMD) is the leading cause of visual impairment in industrialized nations, and like Alzheimer's disease, involves the buildup of beta-amyloid peptides in the brain, as well as sharing similar vascular risk factors. A study of over 2000 older adults (69-97) has revealed an association between early-stage AMD and cognitive impairment, as assessed by the Digit Symbol Substitution Test (a test of attention and processing speed). There was no association with performance on the Modified Mini-Mental State Examination (used to assess dementia).
It’s worth noting that in the same journal two studies into the association between dietary fat intake and AMD appeared. The first, four-year, study involved over 6700 older adults and found that higher trans-unsaturated fat intake was associated with a higher incidence of AMD, while higher omega-3 fatty acid and higher olive oil intake were each associated with a lower incidence. The second, ten-year, study involving nearly 2500 older adults, found regular consumption of fish, greater intake of omega-3 fatty acids, and low intake of linoleic acid (perhaps because a higher intake implies a lower intake of omega-3 oils? linoleic acid is an omega-6 fatty acid), were all associated with a lower incidence of AMD. Fish and omega-3 oils have of course been similarly associated with lower rates of dementia and age-related cognitive impairment.

[447] Baker, M. L., Wang J J., Rogers S., Klein R., Kuller L. H., Larsen E. K., et al.
(2009).  Early age-related macular degeneration, cognitive function, and dementia: the Cardiovascular Health Study.
Archives of Ophthalmology. 127(5), 667 - 673.

[754] Chong, E. W. - T., Robman L. D., Simpson J. A., Hodge A. M., Aung K Z., Dolphin T. K., et al.
(2009).  Fat consumption and its association with age-related macular degeneration.
Archives of Ophthalmology. 127(5), 674 - 680.

[413] Tan, J. S. L., Wang J J., Flood V., & Mitchell P.
(2009).  Dietary fatty acids and the 10-year incidence of age-related macular degeneration: the Blue Mountains Eye Study.
Archives of Ophthalmology. 127(5), 656 - 665.

Age-related vision problems may be associated with cognitive impairment

Age-related macular degeneration (AMD) develops when the macula, the portion of the eye that allows people to see in detail, deteriorates. An investigation into the relationship between vision problems and cognitive impairment in 2,946 patients has been carried out by The Age-Related Eye Disease Study (AREDS) Research Group. Tests were carried out every year for four years. Those who had more severe AMD had poorer average scores on cognitive tests, an association that remained even after researchers considered other factors, including age, sex, race, education, smoking, diabetes, use of cholesterol-lowering medications and high blood pressure. Average scores also decreased as vision decreased. It’s possible that there is a biological reason for the association; it is also possible that visual impairment reduces a person’s capacity to develop and maintain relationships and to participate in stimulating activities.

Chaves, P.H.M. et al. 2006. Association Between Mild Age-Related Eye Disease Study Research Group. 2006. Cognitive Impairment in the Age-Related Eye Disease Study: AREDS Report No. 16. Archives of Ophthalmology,124, 537-543.

The reorganization of the visual cortex in congenitally blind people

Studies indicate that congenitally blind people have superior verbal memory abilities than the sighted. A new study helps us understand why this is so. Some 25% of the human brain is devoted to vision. Until now it was assumed that loss of vision rendered these regions useless. Now it appears that in those blind from birth, the part of the occipital cortex usually involved in vision is utilized for other purposes. Extensive regions in the occipital cortex, in particular the primary visual cortex, are activated not only during Braille reading, but also during performances of verbal memory tasks, such as recalling a list of abstract words. No such activation was found in a sighted control group. It also appears that the greater the occipital activation, the higher the scores in the verbal memory tests.

[944] Amedi, A., Raz N., Pianka P., Malach R., & Zohary E.
(2003).  Early /`visual/' cortex activation correlates with superior verbal memory performance in the blind.
Nat Neurosci. 6(7), 758 - 766.

tags problems: 

Forgetting Intentions

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

Older people with the 'Alzheimer's gene' find it harder to remember intentions

It has been established that those with a certain allele of a gene called ApoE have a much greater risk of developing Alzheimer’s (those with this allele on both genes have 8 times the risk; those with the allele on one gene have 3 times the risk). Recent studies also suggest that such carriers are also more likely to show signs of deficits in episodic memory – but that these deficits are quite subtle. In the first study to look at prospective memory in seniors with the “Alzheimer’s gene”, involving 32 healthy, dementia-free adults between ages of 60 and 87, researchers found a marked difference in performance between those who had the allele and those who did not. The results suggest an exception to the thinking that ApoE status has only a subtle effect on cognition.

[1276] Driscoll, I., McDaniel M. A., & Guynn M. J.
(2005).  Apolipoprotein E and prospective memory in normally aging adults.
Neuropsychology. 19(1), 28 - 34.

'Imagination' helps older people remember to comply with medical advice

A new study suggests a way to help older people remember to take medications and follow other medical advice. Researchers found older adults (aged 60 to 81) who spent a few minutes picturing how they would test their blood sugar were 50% more likely to actually do these tests on a regular basis than those who used other memory techniques. Participants were assigned to one of three groups. One group spent one 3-minute session visualizing exactly what they would be doing and where they would be the next day when they were scheduled to test their blood sugar levels. Another group repeatedly recited aloud the instructions for testing their blood. The last group were asked to write a list of pros and cons for testing blood sugar. All participants were asked not to use timers, alarms or other devices. Over 3 weeks, the “imagination” group remembered 76% of the time to test their blood sugar at the right times of the day compared to an average of 46% in the other two groups. They were also far less likely to go an entire day without testing than those in the other two groups.

[473] Liu, L. L., & Park D. C.
(2004).  Aging and medical adherence: the use of automatic processes to achieve effortful things.
Psychology and Aging. 19(2), 318 - 325.

Alcohol damages day-to-day memory function

A new study involving 763 participants (465 female, 298 males) used self-report questionnaires: the Prospective Memory Questionnaire (PMQ), the Everyday Memory Questionnaire (EMQ), and the UEL (University of East London) Recreational Drug Use Questionnaire, and found that heavy users of alcohol reported making consistently more errors than those who said that they consumed little or no alcohol. More specifically, those who reported higher levels of alcohol consumption were more likely to miss appointments, forget birthdays and pay bills on time (prospective memory), as well as more problems remembering whether they had done something, like locking the door or switching off the lights or oven, or where they had put items like house keys. The study also found a significant increase in reported memory problems by people who claimed to drink between 10 and 25 units each week in comparison to non-drinkers – this is within the ’safe drinking’ limits suggested by U.K. government guidelines.

Ling, L., Heffernan, T.M., Buchanan, T., Rodgers, J., Scholey, A.B. & Parrott, A.C. 2003. Effects of Alcohol on Subjective Ratings of Prospective and Everyday Memory Deficits. Alcoholism: Clinical and Experimental Research, 27(6), 970-974.

tags problems: 

Word-finding Problems

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

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.

Word substitution mistakes have more to do with speech planning than with thought or attention problems

Why is it that we can look at something, know what it is and still call it by the wrong name? A new study suggests that the problem doesn’t lie in haste or a lack of attention, but rather in a fault in speech planning.

Griffin, Z.M. 2004. The eyes are right when the mouth is wrong. Psychological Science, 15 (12), 814-820.

What causes word finding failures in young and older adults

tags problems: 

Source Memory Problems

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

Older adults more likely to "remember" misinformation

In a study involving older adults (average age 75) and younger adults (average age 19), participants studied lists of paired related words, then viewed new lists of paired words, some the same as before, some different, and some with only one of the two words the same. In those cases, the "prime" word, which was presented immediately prior to the test, was plausible but incorrect. The older adults were 10 times more likely than young adults to accept the wrong word and falsely "remember" earlier studying that word. This was true even though older adults had more time to study the list of word pairs and attained a performance level equal to that of the young adults. Additionally, when told they had the option to "pass" when unsure of an answer, older adults rarely used the option. Younger adults did, greatly reducing their false recall. The findings reflect real-world reports of a rising incidence of scams perpetrated on the elderly, which rely on the victim’s poor memory and vulnerability to the power of suggestion.

[629] Jacoby, L. L., Bishara A. J., Hessels S., & Toth J. P.
(2005).  Aging, subjective experience, and cognitive control: dramatic false remembering by older adults.
Journal of Experimental Psychology. General. 134(2), 131 - 148.

Repeated product warnings are remembered as product recommendations

Warnings about particular products may have quite the opposite effect than intended. Because we retain a familiarity with encountered items far longer than details, the more often we are told a claim about a consumer item is false, the more likely we are to accept it as true a little further down the track. Research also reveals that older adults are more susceptible to this error. It is relevant to note that in the U.S. at least, some 80% of consumer fraud victims are over 65.

[489] Skurnik, I., Yoon C., Park D. C., & Schwarz N.
(2005).  How Warnings about False Claims Become Recommendations.
Journal of Consumer Research. 31(4), 713 - 724.

Source-memory problems not an inevitable consequence of aging, but a function of frontal-lobe efficiency

Source memory is memory for the broad contextual aspects surrounding an event, such as who was speaking, or whether you learned something from a book or TV. Previous research has found that it is in this aspect of memory that older people tend to be particularly poor. In a study that compared older individuals with undergraduates, it was found that those who performed above average on frontal-lobe tests, showed no significant impairment of source memory, regardless of age. Those with below-average performance, tended to have impaired source memory (as a group). In other words, source-memory problems are not an inevitable consequence of aging, as has been widely thought, but rather are a function of frontal-lobe efficiency. The proportion of older adults who experience frontal-lobe decline, at what ages, and to what degree, is unknown at this time.
What’s more, when researchers required people to consider the relation between an item and its context (source), age differences in memory performance completely disappeared, suggesting older adults can learn strategies to remember the context better.

[626] Glisky, E. L., Rubin S. R., & Davidson P. S. R.
(2001).  Source Memory in Older Adults: An Encoding or Retrieval Problem?.
Journal of Experimental Psychology: Learning, Memory, and Cognition. 27(5), 1131 - 1146.

tags problems: 


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

More evidence the aging brain is easily distracted

Here’s another study demonstrating that older adults aren't able to filter out distracting information as well as younger adults. The imaging study compared face recognition performance in younger adults (average age 26) and older (average age 70). It was found that, for both groups, difficulties encoding a new face were marked by decreased activity in the hippocampus. But older brains also showed increased activation in the auditory cortex, left prefrontal cortex and medial parietal cortex, showing that they were processing too much irrelevant information from their external environment – the notoriously loud noise of the scanner. Apart from confirming the distractibility of the older brain, the finding also raises questions about imaging studies in general, for older adults. It’s likely that older adults’ cognitive performance have been systematically underestimated.

[520] Stevens, D. W., Hasher L., Chiew K. S., & Grady C. L.
(2008).  A Neural Mechanism Underlying Memory Failure in Older Adults.
J. Neurosci.. 28(48), 12820 - 12824.

Age-related memory loss tied to slip in filtering information quickly

Increasing research in recent years has concluded that one of the problems for the aging brain is a diminished ability to ignore irrelevant information. In fact, many believe it is the major problem for the healthy aging brain. Others believe, more traditionally, that the main problem is a decline in processing speed. A new study shows that both of these happen — in tandem. The difficulty in suppressing irrelevant information occurs because the processing of that irrelevant information has slowed down. This slowdown, at least in visual memory, seems to occur only in the first 200 milliseconds of visual processing, and the difficulty in suppressing irrelevant information occurs only during this period. This suppression failure is thought to impact on working memory.

[553] Gazzaley, A., Clapp W., Kelley J., McEvoy K., Knight R. T., & D'Esposito M.
(2008).  Age-related top-down suppression deficit in the early stages of cortical visual memory processing.
Proceedings of the National Academy of Sciences. 105(35), 13122 - 13126.

More on why older adults are more distractible

A number of recent studies have made it clear that as we age, we find it harder to block out unwanted distractions. A new study used a new brain imaging technique known as EROS to determine whether this is due to faster sensory memory decay or to inefficient filtering of irrelevant sensory information. The study involved 16 young and 16 older participants who read a book of their choice while distracting tones played in the background. The volume of the tones was adjusted so that all the participants heard them at the same level, and the tones were emitted in groups of fives. The young participants showed brain activity in the auditory cortex in response to the first tone in each sequence only, but the older adults' brains responded to all five. The finding supports the view that the growing difficulty at blocking out distractions is due to inefficient filtering of irrelevant sensory information , not faster sensory memory decay.

[1380] Fabiani, M., Low K. A., Wee E., Sable J. J., & Gratton G.
(2006).  Reduced Suppression or Labile Memory? Mechanisms of Inefficient Filtering of Irrelevant Information in Older Adults.
Journal of Cognitive Neuroscience. 18(4), 637 - 650.

Why older adults more vulnerable to distraction from irrelevant information

We know older adults find it harder to filter out irrelevant information. Now a study looking at brain function in young, middle-aged and older adults has identified changes in brain activity that begin gradually in middle age which may explain why. In younger adults, activity in the dorsolateral prefrontal cortex (associated with tasks that require concentration, such as reading) normally increases during the task, while activity in the medial frontal and parietal regions (associated with non-task related activity in a resting state, such as thinking about yourself, what you did last night, monitoring what's going on around you) normally decreases. In middle age (40-60 years), this pattern begins to break down during performance of memory tasks, although performance is not affected (but most of the participants were fairly well educated, so the finding of brain changes without accompanying behavioural changes in the middle-aged group may reflect the "protective effect" of education). Activity in the medial frontal and parietal regions stays turned on while activity in the dorsolateral prefrontal cortex decreases. The imbalance becomes more pronounced in older adults (65+), suggesting there is a gradual, age-related reduction in the ability to suspend non-task-related or "default-mode" activity and engage areas for carrying out memory tasks.

[759] Grady, C. L., Springer M. V., Hongwanishkul D., McIntosh A. R., & Winocur G.
(2006).  Age-related Changes in Brain Activity across the Adult Lifespan.
Journal of Cognitive Neuroscience. 18(2), 227 - 241.

Changes in brain, not age, determine one's ability to focus on task

It’s been established that one of the reasons why older adults may do less well on cognitive tasks is because they have greater difficulty in ignoring distractions, which impairs their concentration. But not all older people are afflicted by this. Some are as focused as young adults. An imaging study has now revealed a difference between the brains of those people who are good at focusing, and those who are poor. Those who have difficulty screening out distractions have less white matter in the frontal lobes. They activated neurons in the left frontal lobe as well as the right. Young people and high-functioning older adults tended to use only the right frontal lobe.

[1117] Colcombe, S. J., Kramer A. F., Erickson K. I., & Scalf P.
(2005).  The implications of cortical recruitment and brain morphology for individual differences in inhibitory function in aging humans.
Psychology and Aging. 20(3), 363 - 375.

Memory loss in older adults due to distractions, not inability to focus

We know that older adults often have short-term memory problems, and this has been linked to problems with attention. An imaging study now provides evidence that these short-term memory problems are associated with an inability to filter out surrounding distractions, rather than problems with focusing attention. It’s been suggested that an inability to ignore distracting information may indeed be at the heart of many of the cognitive problems that accompany aging. It should be noted that this is not an inevitable effect of age — in the study, 6 of the 16 older adults involved had no problems with short-term memory or attention.

[383] Gazzaley, A., Cooney J. W., Rissman J., & D'Esposito M.
(2005).  Top-down suppression deficit underlies working memory impairment in normal aging.
Nat Neurosci. 8(10), 1298 - 1300.

tags problems: 


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

Music training helps you hear better in noisy rooms

I’ve often talked about the benefits of musical training for cognition, but here’s a totally new benefit. A study involving 31 younger adults (19-32) with normal hearing has found that musicians (at least 10 years of music experience; music training before age 7; practicing more than 3 times weekly within previous 3 years) were significantly better at hearing and repeating sentences in increasingly noisy conditions, than the non-musicians. The number of years of music practice also correlated positively with better working memory and better tone discrimination ability. Hearing speech in noisy environments is of course difficult for everyone, but particularly for older adults, who are likely to have hearing and memory loss, and for poor readers.

[960] Parbery-Clark, A., Skoe E., Lam C., & Kraus N.
(2009).  Musician enhancement for speech-in-noise.
Ear and Hearing. 30(6), 653 - 661.

Why it's hard to hear in a crowded room

New research helps explain why it’s difficult for those with impaired hearing to hear conversation involving several different people, particularly in a busy setting such as a restaurant or at a party. It appears that as you attend to a continuous auditory stream (such as one person speaking from one location), your attention gets refined and improved over time. However, if that person gets changing location, or if you have to focus on more than one speaker, then degradation occurs as attention gets switched and begins the process of building up performance again. It’s speculated that the same sort of attentional selectivity may occur with objects in a complex visual scene (think of “Where’s Wally”).

[1148] Best, V., Ozmeral E. J., Kopco N., & Shinn-Cunningham B. G.
(2008).  Object continuity enhances selective auditory attention.
Proceedings of the National Academy of Sciences. 105(35), 13174 - 13178.

Memory impairment associated with sound processing disorder

Central auditory processing dysfunction refers to the situation where hearing in quiet settings is normal or near normal but is substantially impaired in the presence of competing noise or in other difficult listening situations. Such a problem is not helped by amplification and requires alternative rehabilitation strategies. Central auditory processing has been found to be impaired in those with dementia. Now a study comparing individuals with dementia, those with mild memory impairment but without a dementia diagnosis, and those without memory loss, has found that scores on central auditory processing tests were significantly lower in both the group with dementia and in the group with mild memory impairment, compared to controls.

[302] Gates, G. A., Anderson M. L., Feeney P. M., McCurry S. M., & Larson E. B.
(2008).  Central auditory dysfunction in older persons with memory impairment or Alzheimer dementia.
Archives of Otolaryngology--Head & Neck Surgery. 134(7), 771 - 777.

Hearing loss in older adults may compromise cognitive resources for memory

A study involving older adults with good hearing and a group with mild-to-moderate hearing loss has found that even when older adults could hear words well enough to repeat them, their ability to memorize and remember these words was poorer in comparison to other individuals of the same age with good hearing. The researchers suggest that the effect of expending extra effort comprehending words means there are fewer cognitive resources for higher level comprehension. Working memory capacity tends to diminish as we age.

[394] Wingfield, A., Tun P. A., & McCoy S. L.
(2005).  Hearing Loss in Older Adulthood.
Current Directions in Psychological Science. 14(3), 144 - 148.

tags memworks: 


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