Information Center > News & Views >

News reports of research into memory March 2007

For index of all headlines, go to News & Views main page

To look at research reports sorted by subject go to Research Reports

For news about Alzheimer's research go directly to the Alzheimer's page

You can find links to the journals referred to on this site here: Journal links

March 2007

Executive function as important as IQ for math success

A study of 141 preschoolers from low-income homes has found that a child whose IQ and executive functioning were both above average was three times more likely to succeed in math than a child who simply had a high IQ. The parts of executive function that appear to be particularly linked to math ability in preschoolers are working memory and inhibitory control. In this context, working memory may be thought of as the ability to keep information or rules in mind while performing mental tasks. Inhibitory control is the ability to halt automatic impulses and focus on the problem at hand. Inhibitory control was also important for reading ability. The finding offers the hope that training to improve executive function will improve academic performance.
The research was published in the February issue of Child Development. Full reference
http://www.sciam.com/article.cfm?articleID=90377FAE-E7F2-99DF-3A1204FC5F2BF0F7

Right parietal lobe implicated in dyscalculia

By temporarily knocking out an area in the right parietal lobe (the right intraparietal sulcus), researchers have induced dyscalculia in normal subjects, providing strong evidence that dyscalculia is caused by malfunction in this area. These findings were further validated by testing participants suffering from developmental dyscalculia. Although less well-known, dyscalculia is as prevalent as dyslexia and attention deficit hyperactivity disorder (around 5%).
The findings were published online ahead of print on March 22 in Current Biology. Full reference
http://www.sciencedaily.com/releases/2007/03/070322132931.htm
http://www.eurekalert.org/pub_releases/2007-03/ucl-tro032107.php

Early music training 'tunes' auditory system

Mandarin is a tonal language, that is, the pitch pattern is as important as the sound of the syllables in determining the meaning of a word. In a small study, a Mandarin word was presented to 20 adults as they watched a movie. All were native English speakers with no knowledge of Mandarin, but half had at least six years of musical instrument training starting before the age of 12, while half had minimal or no musical training. As the subjects watched the movie, the researchers measured the accuracy of their brainstem ability to track three differently pitched "mi" sounds. Those who were musically trained were far better at tracking the three different tones than the non-musicians. The study is the first to provide concrete evidence that playing a musical instrument significantly enhances the brainstem's sensitivity to speech sounds, and supports the view that experience with music at a young age can "fine-tune" the brain's auditory system. The findings are in line with previous studies suggesting that musical experience can improve one's ability to learn tone languages in adulthood, and are also consistent with studies revealing anomalies in brainstem sound encoding in some children with learning disabilities which can be improved by auditory training. The findings are also noteworthy for implicating the brainstem in processing that has been thought of as exclusively involving the cortex.
The study appears in the April issue of Nature Neuroscience. Full reference
http://www.eurekalert.org/pub_releases/2007-03/nu-rfm031207.php
http://www.nytimes.com/2007/03/20/science/20lang.html?_r=1&oref=slogin

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

Prefrontal cortex loses neurons during adolescence

A rat study has found that adolescents lose neurons in the ventral prefrontal cortex in adolescence, with females losing about 13% more neurons than males. Human studies have found gradual reductions in the volume of gray matter in the prefrontal cortex from adolescence to adulthood, but this finding that neurons are actually dying is new, and indicates that the brain reorganizes in a very fundamental way in adolescence. The number of neurons in the dorsal prefrontal cortex didn’t change, although the number of glial cells increased there (while remaining stable in the ventral area). The finding could have implications for understanding disorders that often arise in late adolescence, such as schizophrenia and depression, and why addictions that start in adolescence are harder to overcome than those that begin in adulthood.
The study appeared in the February 9 issue of Neuroscience. Full reference
http://www.news.uiuc.edu/news/07/0312juraska.html
http://www.sciencedaily.com/releases/2007/03/070314093257.htm

Antidepressants improve thinking after a stroke

Executive dysfunction is common after stroke and may impair long-term outcome. A small study of people who had had a stroke during the previous six months has found that, although there was no difference in executive function between those given antidepressants and those given a placebo at the end of the 12-week treatment period, there was a significant difference 21 months after the treatment ended. Those who had been given the placebo showed continued worsening of executive functions, whereas the group treated with antidepressants had clear and significant improvement, regardless of how their depressive symptoms changed. The researchers speculate that antidepressants may foster recovery of neural tissue not directly destroyed by the stroke, yet because the process is slow, it takes months.
The study results appear in the March issue of the British Journal of Psychiatry. Full reference
http://www.eurekalert.org/pub_releases/2007-03/uoi-aip030207.php

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.
The study was published in the March 13 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2007-03/aaon-osc030607.php

Kids learn words best by working out meaning

An undergraduate project involving 100 children aged 3 to 3 ½, provides evidence that children learn words better when they figure out the words' meaning for themselves, rather than when they are simply told their meaning.
http://www.sciencedaily.com/releases/2007/03/070315213151.htm

Selective amnesia — How a traumatic memory can be wiped out

A rat study has succeeded in erasing a single, specific, fearful memory, leaving other memories intact. Such an approach may eventually help sufferers of post-traumatic stress disorder (PTSD). The treatment involves the application of a drug while the memory is being recalled — a process that renders the memory vulnerable to disruption.
The results were published online March 11 in Nature Neuroscience. Full reference
http://www.nature.com/news/2007/070305/full/070305-17.html
http://www.eurekalert.org/pub_releases/2007-03/c-sah033007.php

Social memory localized

An imaging study has identified the medial prefrontal cortex as being the key structure in remembering social information (involving people and their interactions) from a picture. Previous studies have implicated this region with thinking about one’s self and others. This finding reveals that the region is involved not only in processing social information, but also storing it. The finding may help us understand disorders which affect social and relational skills, such as schizophrenia and autism.
The study was presented in the February issue of the Journal of Cognitive Neuroscience. Full reference
http://www.physorg.com/news94794207.html
http://www.physorg.com/news94836363.html
http://www.eurekalert.org/pub_releases/2007-03/c-tfo033007.php

Disentangling attention

A new study provides more evidence that the ability to deliberately focus your attention is physically separate in the brain from the part that helps you filter out distraction. The study trained monkeys to take attention tests on a video screen in return for a treat of apple juice. When the monkeys voluntarily concentrated (‘top-down’ attention), the prefrontal cortex was active, but when something distracting grabbed their attention (‘bottom-up’ attention), the parietal cortex became active. The electrical activity in these two areas vibrated in synchrony as they signaled each other, but top-down attention involved synchrony that was stronger in the lower-frequencies and bottom-up attention involved higher frequencies. These findings may help us develop treatments for attention disorders.
The study was published in the March 30 issue of Science. Full reference
http://dsc.discovery.com/news/2007/03/29/attention_hea.html?category=health

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.
The findings were published in the March 13 issue of the Proceedings of the National Academy of Sciences. Full reference
Full text is available at http://www.pnas.org/cgi/reprint/104/11/4642
http://www.physorg.com/news94384934.html
http://www.sciencedaily.com/releases/2007/03/070329092022.htm
http://www.eurekalert.org/pub_releases/2007-03/cumc-nrs032807.php

Humans aren’t the only ones to think about what they know

As we get smarter about designing experiments and working out how to ask the right questions, the gap between human and non-human cognition keeps closing. Now a rat study has found evidence that rats can think about whether they know something or not. The study involved offering rats rewards for classifying a brief tone as either short or long. A right answer led to a large food reward; a wrong one, nothing. But on some tests runs, before starting, the rats were given a chance to back out of the test, in which case they got a small reward anyway. In some of the tests, the signal lengths were very different, making the discrimination very easy. But in others the difference was a lot harder to discern. In such a case, if the rats realized they couldn’t be sure of the answer, they would be better to forego the test and get the small, but guaranteed prize. Which was what was found.
The findings appeared online ahead of print on March 8 in Current Biology. Full reference
http://www.world-science.net/othernews/070308_rats.htm
http://www.eurekalert.org/pub_releases/2007-03/cp-mfw030607.php

Return to top