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
Stress & anxiety
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.
http://www.eurekalert.org/pub_releases/2009-07/uab-sse072309.php
Stressed brains rely on habit
And another rat study has found that rats stressed repeatedly and unpredictably for three weeks were more likely than unstressed animals to continue performing habitual behaviors, even when it no longer made sense to do so. This behavior was correlated with reductions in the prelimbic cortex of the medial prefrontal cortex and the dorsomedial striatum (both implicated in goal-directed actions), and increases in the size of the dorsolateral striatum (necessary for habit). The finding follows on from previous research showing that habit formation involves a switch between neural circuits associated with goal-directed behavior and those controlling habitual behavior. The findings have implications for therapies for stress-related disorders and addictive behavior.
[517] Dias-Ferreira, E., Sousa J. C., Melo I., Morgado P., Mesquita A. R., Cerqueira J. J., et al.
(2009). Chronic Stress Causes Frontostriatal Reorganization and Affects Decision-Making.
Science. 325(5940), 621 - 625.
http://www.the-scientist.com/blog/display/55873/
Stress disrupts task-switching, but the brain can bounce back
A new neuroimaging study involving 20 male M.D. candidates in the middle of preparing for their board exams has found that they had a harder time shifting their attention from one task to another after a month of stress than other healthy young men who were not under stress. The finding replicates what has been found in rat studies, and similarly correlates with impaired function in an area of the prefrontal cortex that is involved in attention. However, the brains recovered their function within a month of the end of the stressful period.
[829] Liston, C., McEwen B. S., & Casey B. J.
(2009). Psychosocial stress reversibly disrupts prefrontal processing and attentional control.
Proceedings of the National Academy of Sciences. 106(3), 912 - 917.
Full text available at http://www.pnas.org/content/106/3/912.abstract
http://www.eurekalert.org/pub_releases/2009-01/ru-sdh012709.php
Psychological distress, not depression, linked to increased risk of stroke
A study following 20,627 people for an average of 8.5 years has found that psychological distress was associated with an increased risk of stroke and that the risk of stroke increased the more distress the participants reported. This association remained the same regardless of cigarette smoking, systolic blood pressure, overall blood cholesterol, obesity, previous heart attack, diabetes, social class, education, high blood pressure treatment, family history of stroke and recent antidepressant medication use. However, there was no increased risk for people who had experienced an episode of major depression in the past year or at any point in their lifetime.
[1298] Surtees, P. G., Wainwright N. W. J., Luben R. N., Wareham N. J., Bingham S. A., & Khaw K. - T.
(2008). Psychological distress, major depressive disorder, and risk of stroke.
Neurology. 70(10), 788 - 794.
http://www.eurekalert.org/pub_releases/2008-03/aaon-pdn022608.php
Short-term stress can affect learning and memory
We know that long-lasting, severe stress can impair cell communication in the hippocampus. Now rodent studies have demonstrated that the same outcome can happen with short-term stress. But rather than involving the familiar stress hormone cortisol, acute stress activated corticotropin releasing hormones, which led to the rapid disintegration of dendritic spines in the hippocampus, thus limiting the ability of synapses to collect and store memories.
[981] Chen, Y., Dube C. M., Rice C. J., & Baram T. Z.
(2008). Rapid Loss of Dendritic Spines after Stress Involves Derangement of Spine Dynamics by Corticotropin-Releasing Hormone.
J. Neurosci.. 28(11), 2903 - 2911.
http://www.eurekalert.org/pub_releases/2008-03/uoc--ssc031008.php
Correct levels of stress hormones boost learning
Although it’s known that cortisol production is related to stress and has an impact on learning in humans, that impact is not well understood, because of the difficulties of controlling cortisol levels in humans. A study using ground squirrels has now found that they learn more quickly if they have a modest amount of cortisol, rather than either high or low levels of cortisol.
[252] Mateo, J. M.
(2008). Inverted-U shape relationship between cortisol and learning in ground squirrels.
Neurobiology of Learning and Memory. 89(4), 582 - 590.
http://www.eurekalert.org/pub_releases/2008-03/uoc-rws031208.php
Stress hormone impacts memory, learning in diabetic rodents
A rodent study sheds light on why diabetes can impair cognitive function. The study found that increased levels of a stress hormone (called cortisol in humans) in diabetic rats impaired synaptic plasticity and reduced neurogenesis in the hippocampus. When levels returned to normal, the hippocampus recovered. Cortisol production is controlled by the hypothalamic-pituitary axis (HPA). People with poorly controlled diabetes often have an overactive HPA axis and excessive cortisol.
[1050] Stranahan, A. M., Arumugam T. V., Cutler R. G., Lee K., Egan J. M., & Mattson M. P.
(2008). Diabetes impairs hippocampal function through glucocorticoid-mediated effects on new and mature neurons.
Nature Neuroscience. 11(3), 309 - 317.
http://www.eurekalert.org/pub_releases/2008-02/nioa-shi021508.php
How stress affects memory
We know stress affects memory. Now a rat study tells us one of the ways it does that. Cell recordings in the hippocampus revealed that, when a mouse moves from one location to another, particular cells fired at each location. When the mouse returned to an earlier location, the same cells fire. However, following stress, the cells that fired in a particular location still fired at the same location, but tended to fire at a different frequency. Stress also reduce the level of LTP at the synapses.
[1295] Kim, J. J., Lee H. J., Welday A. C., Song E. Y., Cho J., Sharp P. E., et al.
(2007). Stress-induced alterations in hippocampal plasticity, place cells, and spatial memory.
Proceedings of the National Academy of Sciences. 104(46), 18297 - 18302.
http://www.sciencentral.com/articles/view.php3?article_id=218393035
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.
http://www.eurekalert.org/pub_releases/2007-02/uoc-hap021607.php
Lifestyle changes improve seniors’ memory surprisingly quickly
A small 14-day study found that those following a memory improvement plan that included memory training, a healthy diet, physical exercise, and stress reduction, showed a 5% decrease in brain metabolism in the dorsal lateral prefrontal region of the brain (involved in working memory) suggesting they were using their brain more efficiently. This change in activity was reflected in better performance on a cognitive measure controlled by this brain region, and participants reported that they felt their memory had improved. The memory training involved doing brainteasers, crossword puzzles and memory exercises. Diet involved eating 5 small meals daily (to prevent fluctuations in blood glucose levels) that were rich in omega-3 fats, low-glycemic index carbohydrates (e.g., whole grains) and antioxidants. Physical exercise involved brisk walking and stretching, and stress reduction involved stretching and relaxation exercises.
The study was presented at the American College of Neuropsychopharmacology's Annual Meeting on December 11-15, in Hawaii.
http://www.eurekalert.org/pub_releases/2005-12/g-nsf121205.php
Stress interferes with problem-solving; Beta-blocker may help
New research suggests that an experience as simple as watching graphically violent or emotional scenes in a movie can induce enough stress to interfere with problem-solving abilities, and that a beta-blocker medication could promote the ability to think flexibly under stressful conditions. Neither the stress nor the beta-blocker affected memory. The research not only has implications for understanding the range of effects of stress on thinking, but could also have broader clinical implications for patients with anxiety disorders or substance abuse problems.
Renner, K., Alexander, J., Hillier, A., Smith, R. & Tivarus, M. 2005. Presented at the annual Society for Neuroscience meeting in Washington, D.C.
http://www.eurekalert.org/pub_releases/2005-11/osu-siw110905.php
Early life stress can lead to memory loss and cognitive decline in middle age
Age-related cognitive decline is probably a result of both genetic and environmental factors. A rat study has demonstrated that some of these environmental factors may occur in early life. Among the rats, emotional stress in infancy showed no ill effects by the time the rats reached adulthood, but as the rats reached middle age, cognitive deficits started to appear in those rats who had had stressful infancies, and progressed much more rapidly with age than among those who had had nurturing infancies. Middle-aged rats who had been exposed to early life emotional stress showed deterioration in brain-cell communication in the hippocampus.
[1274] Brunson, K. L., Kramar E., Lin B., Chen Y., Colgin L. L., Yanagihara T. K., et al.
(2005). Mechanisms of Late-Onset Cognitive Decline after Early-Life Stress.
J. Neurosci.. 25(41), 9328 - 9338.
http://www.eurekalert.org/pub_releases/2005-10/uoc--els100605.php
Stress bad for the brain
A study of older adults for three to six years has found that those with continuous high levels of the stress hormone cortisol performed poorly on memory tests and had a 14% smaller hippocampus. A further study involving young adults and children between the ages of six and fourteen found that even an acute increase in cortisol can lead to reversible memory impairments in young adults, and that children from low socio-economic status environments had higher cortisol levels than those from high SES homes. Children from low SES homes tended to process positive and negative attributes more negatively than children from high SES homes, and this type of processing was significantly related to basal cortisol levels at ages 10, 12 and 14.
[1415] Lupien, S. J., Fiocco A. J., Wan N., Maheu F., Lord C., Schramek T., et al.
(2005). Stress hormones and human memory function across the lifespan.
Psychoneuroendocrinology. 30(3), 225 - 242.
http://www.eurekalert.org/pub_releases/2005-05/mu-tst051705.php
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.
http://www.eurekalert.org/pub_releases/2005-02/bpl-wup020705.php
Anxiety good for memory recall, bad for solving complex problems
Cognitive tests given to 19 first-year medical students one to two days before a regular classroom exam, and then a week after the exam, found that, before the exam, students were better able to accurately recall a list of memorized numbers, but did less well on tests that required them to consider many possibilities in order to come up with a reasonable answer. A week after the exam, the opposite was true. It is assumed that the difference in results reflects the effects of stress.
Jessa Alexander & David Beversdorf presented their findings on October 25 in San Diego at the annual Society for Neuroscience conference.
http://www.eurekalert.org/pub_releases/2004-10/osu-agf101904.php
Estrogen effect on memory influenced by stress
The question of whether estrogen helps memory and cognition in women has proven surprisingly difficult to answer, with studies giving conflicting results. Now it seems the answer to that confusion is: it depends. And one of the things it depends on may be the level of stress the woman is experiencing. A rat study has found that the performance of female rats in a water maze was affected by the interaction of hormone level (whether the rat was estrous or proestrous) with water temperature (a source of physical stress). Those rats with high hormone levels did better when the water was warm, while those with low hormone levels did better when the water was cold. The researchers suggest both timing and duration of stress might be factors in determining the effect of hormones on cognition.
[384] Rubinow, M. J., Arseneau L. M., Beverly L. J., & Juraska J. M.
(2004). Effect of the Estrous Cycle on Water Maze Acquisition Depends on the Temperature of the Water..
Behavioral Neuroscience. 118(4), 863 - 868.
http://www.eurekalert.org/pub_releases/2004-08/uoia-sss082704.php
Stress reactions no guarantee of authenticity
Physical stress reactions have often been taken as evidence for the authenticity of a memory. A recent study investigated people with “memories” of alien abductions (on the grounds that these are the memories least likely to be true) and found that those who believed they had been abducted by aliens responded physically to recall of that memory in the same way as to recall of other, true, stressful events. The finding suggests that a person’s reaction to a memory is no evidence for whether or not it truly happened.
[1161] McNally, R. J., Lasko N. B., Clancy S. A., Macklin M. L., Pitman R. K., & Orr S. P.
(2004). Psychophysiological responding during script-driven imagery in people reporting abduction by space aliens.
Psychological Science: A Journal of the American Psychological Society / APS. 15(7), 493 - 497.
http://www.eurekalert.org/pub_releases/2004-06/aps-ptw062104.php
Stress no aid to memory
Numerous studies have questioned the accuracy of recall of traumatic events, but the research is often dismissed as artificial and not intense enough to simulate real-life trauma. A new study has used real stress: 509 active duty military personnel enrolled in survival school training were deprived of food and sleep 48 hours and then interrogated. A day later, only 30% of those presented with a line-up could identify the right person, only 34% identified their interrogator from a photo-spread and 49% from single photos shown sequentially (putting the interrogator in the same clothing boosted correct identification to 66%). Thirty people even got the gender wrong. Those subjected to physical threats (half the participants) performed worse.
[269] Morgan, C. A., Hazlett G., Doran A., Garrett S., Hoyt G., Thomas P., et al.
(Submitted). Accuracy of eyewitness memory for persons encountered during exposure to highly intense stress.
International Journal of Law and Psychiatry. 27(3), 265 - 279.
http://www.newscientist.com/news/news.jsp?id=ns99995089
http://www.eurekalert.org/pub_releases/2004-06/yu-emp060304.php
http://www.eurekalert.org/pub_releases/2004-06/ns-mfy060904.php
Anxiety over math blocks learning
The so-called "math block" is notorious - why do we have such a term? Do we talk about a "geography block", or a "physics block"? But we do talk of a reading block. Perhaps the reason for both is the same.
The amount of information you can work with at one time has clear limits, defined by your working memory capacity. When we are anxious, part of our working memory is taken up with our awareness of these fears and worries, leaving less capacity available for processing (which is why students who are very anxious during exams usually perform well below their capabilities). Processes such as reading and working with numbers are very sensitive to working memory capacity because they place such demands on it.
A recently reported study by Mark H. Ashcraft and Elizabeth P. Kirk, both psychologists at Cleveland (Ohio) State University, provides the first solid evidence that, indeed, math-anxious people have working memory problems as they do math.
[2549] Ashcraft, M. H., & Kirk E. P.
(2001). The relationships among working memory, math anxiety, and performance.
Journal of Experimental Psychology: General. 130(2), 224 - 237.
http://www.sciencenews.org/20010630/fob4.asp
Fear & trauma
Scent of fear impacts cognitive performance
A study involving 75 female students found that those who were exposed to chemicals from fear-induced sweat performed more accurately on word-association tasks than did women exposed to chemicals from other types of sweat or no sweat at all. When processing meaningfully related word pairs, the participants exposed to the fear chemicals were significantly more accurate than those in either the neutral sweat or the control (no-sweat) condition. When processing word pairs that were ambiguous in threat content, such as one neutral word paired with a threatening word or a pair of neutral words, subjects in the fear condition were significantly slower in responding than those in the neutral sweat condition.
Chen, D., Katdare, A. & Lucas, N. 2006. Chemosignals of Fear Enhance Cognitive Performance in Humans. Chemical Senses, Advance Access published on March 9, 2006
http://www.eurekalert.org/pub_releases/2006-03/ru-sof033106.php
Memory of fear more complex than supposed
It seems that fear memory is more complex than has been thought. A new mouse study has shown that not only the hippocampus and amygdala are involved, but that the prefrontal cortex is also critical. The development of the fear association doesn’t occur immediately after a distressing event, but develops over time. The process, it now seems, depends directly on a protein called NR2B.
[243] Li, B. - M., Zhao M. - G., Toyoda H., Lee Y. - S., Wu L. - J., Ko S. W., et al.
(2005). Roles of NMDA NR2B Subtype Receptor in Prefrontal Long-Term Potentiation and Contextual Fear Memory.
Neuron. 47(6), 859 - 872.
http://www.eurekalert.org/pub_releases/2005-09/uot-sco091505.php
How trauma triggers long-lasting memories in the brain
A rat study sheds more light on why emotional experiences tend to be better remembered than emotionally neutral events. The study found that emotionally arousing events activated the amygdala, which then increased a specific protein — activity-regulated cytoskeletal protein ("Arc") — in the neurons in the hippocampus. It's thought that Arc helps store these memories by strengthening the synapses.
[922] McIntyre, C. K., Miyashita T., Setlow B., Marjon K. D., Steward O., Guzowski J. F., et al.
(2005). Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein in the hippocampus.
Proceedings of the National Academy of Sciences of the United States of America. 102(30), 10718 - 10723.
http://www.eurekalert.org/pub_releases/2005-07/uoc--nih072505.php
Why traumatic memories have the power they do
In the first imaging study to look at retrieval of emotional memories after a long period (one year after encoding), researchers found that people did recall emotional images, both pleasant and unpleasant, better than emotionally-neutral images. This recall was associated with higher activity in both the amygdala and the hippocampus. The synchronicity of activity between these two regions suggested that each region triggers the other, creating a self-reinforcing "memory loop" in which an emotional cue might trigger recall of the event, which then loops back to a re-experiencing of the emotion of the event. The findings suggest why people subject to traumatic events may be trapped in a cycle of emotion and recall that aggravates post-traumatic stress disorder, and may also suggest why therapies in which people relive such memories and reshape perspective to make it less traumatic can help people cope with such memories.
[198] Dolcos, F., LaBar K. S., & Cabeza R.
(2005). Remembering one year later: Role of the amygdala and the medial temporal lobe memory system in retrieving emotional memories.
Proceedings of the National Academy of Sciences of the United States of America. 102(7), 2626 - 2631.
http://www.eurekalert.org/pub_releases/2005-03/du-ems030805.php
Reducing the trauma of traumatic memories
For some, stressful memories can reawaken intense fear, with undesirable consequences. A new study involving mice has found that such stress induces a change in the expression of the acetylcholinesterase gene, which normally produces a vital protein that adheres to neuronal synapses. Following stress, however, the same gene produces large quantities of a protein with modified properties that results in heightened electrical signals in the nerve cells communicating through these synapses. The effect is to create reactions of extreme fright or immobilizing shock. Later encounter with a context which triggers those stressful memories can set off that same neuronal reaction. The researchers have developed an "antisense" agent that acts to neutralize the process whereby the modified protein is produced, thereby preventing the extreme reaction.
[1002] Soreq, H., Blank T., Nijholt I., Farchi N., Kye M., Sklan E. H., et al.
(2003). Stress-induced alternative splicing of acetylcholinesterase results in enhanced fear memory and long-term potentiation.
Mol Psychiatry. 9(2), 174 - 183.
http://www.eurekalert.org/pub_releases/2003-12/huoj-hug121103.php
http://www.eurekalert.org/pub_releases/2003-12/mp-abm120803.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
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
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.
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.
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
Interactions with other races can impair mental capacity in the strongly prejudiced
A new approach on an old theme — the effect of stress on cognitive function. The study looked at the short-term effects of racial prejudice. White college students were assessed for racial bias and then had a conversation with either a black or white person. After the conversation, they were given the Stroop test (participants are presented with color words, which are either in the same color as they name, or not; they are required to respond on the basis of the color of the word, not the name. The test requires a surprising amount of concentration.) For those who had talked with a black person, the greater the amount of racial bias, the worse the student did on the Stroop test. This is assumed to be due to the stress caused by the interaction.
[833] Richeson, J. A., & Shelton N. J.
(2003). When prejudice does not pay: Effects of Interracial Contact on Executive Function.
Psychological Science. 14(3), 287 - 290.
http://www.eurekalert.org/pub_releases/2003-04/pu-tpo043003.php
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
, and 