News reports of research into memory March 2008

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 2008

Why we don't always learn from our mistakes

A study of the tip-of-the-tongue (TOT) phenomenon suggests that most errors are repeated because the very act of making a mistake, despite receiving correction, constitutes the learning of that mistake. The study asked students to retrieve words after being given a definition. If that produced a TOT state, they were randomly assigned to spend either 10 or 30 seconds trying to retrieve the answer before finally being shown it. When tested two days later, it was found that they tended to TOT on the same words as before, and were especially more likely to do so if they had spent a longer time trying to retrieve them The longer time in the error state appears to reinforce that incorrect pattern of brain activation that caused the error.
The research appeared in the April issue of The Quarterly Journal of Experimental Psychology. Full reference
http://www.physorg.com/news126265455.html

Listening to cell phones significantly impairs drivers

A brain imaging study in which 29 volunteers used a driving simulator while inside an MRI brain scanner, has revealed that just listening on a cell phone reduces by 37% the amount of brain activity associated with driving. There was also a significant deterioration in the quality of driving. Subjects who were listening committed more lane maintenance errors, such as hitting a simulated guardrail, and deviating from the middle of the lane. While other distractions, such as eating, listening to the radio or talking with a passenger, also can divert a driver, there are reasons to believe cell phones may be especially distracting, because of the social demand and the fact that the person on the phone can’t know when the driver needs increased attention.
The findings were reported online February 19 in Brain Research. Full reference
http://www.eurekalert.org/pub_releases/2008-03/cmu-cms030408.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.
The study was published in the March 4 issue of Neurology. Full reference
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.
The study appeared in the March 12 edition of the Journal of Neuroscience. Full reference
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.
The study was published online March 4 in Neurobiology of Learning and Memory. Full reference
http://www.eurekalert.org/pub_releases/2008-03/uoc-rws031208.php

French maritime pine bark improves memory in elderly

A double-blind, placebo controlled, matched pairs study examined the effects of Pycnogenol (an antioxidant plant extract from the bark of the French maritime pine tree) on a range of cognitive and biochemical measures in 101 senior individuals aged 60-85 years old. Participants had a daily dose of 150mg for three months. Pycnogenol improved both numerical working memory as well as spatial working memory. Blood samples revealed that F2-isoprostanes significantly decreased with Pycnogenol, a sign of reduced oxidation of nerve membranes, suggesting that the antioxidant activity of Pycnogenol plays a major role for the clinical effects. Several recent research studies have found Pycnogenol reduced ADHD symptoms such as hyperactivity and improved attention, concentration and motor-visual coordination in children with ADHD. Pycnogenol extract has been studied for 35 years and is available in more than 600 dietary supplements.
The study will appear in a forthcoming issue of in the Journal of Psychopharmacology, and was presented at the 2008 World Congress on Oxidants and Antioxidants in Biology in Santa Barbara, CA.
http://www.eurekalert.org/pub_releases/2008-03/mg-nsp031708.php

White-matter changes linked to gait and balance problems

A three-year study involving 639 adults between the ages of 65 and 84 has found that people with severe white matter changes (leukoaraiosis) were twice as likely to score poorly on walking and balance tests as those people with mild white matter changes. The study also found people with severe changes were twice as likely as the mild group to have a history of falls. The moderate group was one-and-a-half times as likely as the mild group to have a history of falls. Further research will explore the effect of exercise.
The study was published in the March 18 issue of Neurology. Full reference
http://www.physorg.com/news124990876.html

Injection of human umbilical cord blood helps aging brain

A rat study has found that a single intravenous injection of human umbilical cord blood mononuclear cells in aged rats significantly improved the microenvironment of the aged hippocampus and rejuvenated the aged neural stem/progenitor cells. The increase in neurogenesis seemed to be due to a decrease in inflammation. The results raise the possibility of cell therapy to rejuvenate the aged brain.
The findings were published online February 14 at BMC Neuroscience. Full reference
http://www.physorg.com/news124384387.html

Different use of brain areas may explain memory problems in schizophrenics

New research indicates that schizophrenics’ memory problems may be related to differences in how their brains process information. While both schizophrenic patients and healthy individuals used their frontal cortex while remembering and forgetting, healthy subjects used the right side when asked to remember spatial locations and schizophrenics used a wider network in both hemispheres. When healthy people were correct in their remembering, there was an increased activation of the right frontal cortex, an increase that didn’t occur when they couldn’t remember, and this was associated with a lack of confidence in their memory. However, schizophrenic patients showed an activation pattern on error trials indicating that they were remembering something, albeit incorrect. This was associated with a feeling of confidence about their memory.
The report appeared March 12 in the open access journal PLOS One. Full reference
Full text at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0001760
http://www.eurekalert.org/pub_releases/2008-03/vu-duo031008.php

Head injuries result in widespread brain tissue loss one year later

A study of traumatic brain injury (TBI) patients who span the full range of severity from mild to moderate and severe has revealed that the more severe the injury, the greater the loss of brain tissue one year after injury, particularly white matter. Researchers were surprised at the extent of tissue loss, which was widespread even in patients who had no obvious lesions, and was discernible even in the mild TBI group.
The study was published in the March 4 issue of Neurology. Full reference
http://www.eurekalert.org/pub_releases/2008-03/bcfg-hir022808.php

Strong links between arts education and cognitive development

The Dana Consortium study, a 3 year study by cognitive neuroscientists from seven universities, has been investigating the effects of music, dance, and drama education on other types of learning. The researchers have identified eight key points:

An interest in a performing art leads to a high state of motivation that produces the sustained attention necessary to improve performance and the training of attention that leads to improvement in other domains of cognition.
Genetic studies have begun to yield candidate genes that may help explain individual differences in interest in the arts.
Specific links exist between high levels of music training and the ability to manipulate information in both working and long-term memory; these links extend beyond the domain of music training.
In children, there appear to be specific links between the practice of music and skills in geometrical representation, though not in other forms of numerical representation.
Correlations exist between music training and both reading acquisition and sequence learning. One of the central predictors of early literacy, phonological awareness, is correlated with both music training and the development of a specific brain pathway.
Training in acting appears to lead to memory improvement through the learning of general skills for manipulating semantic information.
Adult self-reported interest in aesthetics is related to a temperamental factor of openness, which in turn is influenced by dopamine-related genes.
Learning to dance by effective observation is closely related to learning by physical practice, both in the level of achievement and also the neural substrates that support the organization of complex actions. Effective observational learning may transfer to other cognitive skills.

You can download the complete report at http://www.dana.org/news/publications/publication.aspx?id=10760
http://www.eurekalert.org/pub_releases/2008-03/df-dfr030408.php

Grammar impairment among SLI children

Specific language impairment (SLI) affects 7% of children and is a major cause of many not reaching their educational potential. A new study reveals that for a sub-group (G-SLI) the problem lies specifically in grammar processing. These children had a specific deficit in brain circuitry involved in grammatical processing, but they appeared to be partially compensating by using neural circuitry associated with vocabulary/word meaning or world knowledge (semantic processing). The finding suggests that educational methods that enhance these compensatory mechanisms may help such children overcome their difficulties.
The study was published online in the open access journal PLoS ONE. Full reference
Full text at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0001832
http://www.physorg.com/news124538788.html

Connection between language and movement

A study of all three groups of birds with vocal learning abilities – songbirds, parrots and hummingbirds – has revealed that the brain structures for singing and learning to sing are embedded in areas controlling movement, and areas in charge of movement share many functional similarities with the brain areas for singing. This suggests that the brain pathways used for vocal learning evolved out of the brain pathways used for motor control. Human brain structures for speech also lie adjacent to, and even within, areas that control movement. The findings may explain why humans talk with our hands and voice, and could open up new approaches to understanding speech disorders in humans. They are also consistent with the hypothesis that spoken language was preceded by gestural language, or communication based on movements. Support comes from another very recent study finding that mice engineered to have a mutation to the gene FOXP2 (known to cause problems with controlling the formation of words in humans) had trouble running on a treadmill.
Relatedly, a study of young children found that 5-year-olds do better on motor tasks when they talk to themselves out loud (either spontaneously or when told to do so by an adult) than when they are silent. The study also showed that children with behavioral problems (such as ADHD) tend to talk to themselves more often than children without signs of behavior problems. The findings suggest that teachers should be more tolerant of this kind of private speech. (http://www.eurekalert.org/pub_releases/2008-03/gmu-pkd032808.php ; Full reference)
The results appeared online March 12 in PLoS ONE. Full reference
http://www.physorg.com/news124526627.html
http://www.sciam.com/article.cfm?id=song-learning-birds-shed

Language feature unique to human brain identified

Multiple bundles of nerve fibers, the arcuate fasciculus, connect Broca's and Wernicke's areas, the language centers of the brain. Those with damage to the arcuate fasciculus have severe difficulty speaking and understanding others. Brain scans of 10 live humans, three deceased chimpanzees, two deceased macaque monkeys, plus one live chimpanzee and one live macaque have revealed dramatic differences between humans and the other primates. Although the arcuate fasciculus in all three species was hooked up to the frontal cortex (including Broca’s area), only in humans did the arcuate fasciculus extend deeply into language-associated areas of the temporal cortex, such as Wernicke's area.
The report appeared online March 23 in Nature Neuroscience. Full reference
http://sciencenow.sciencemag.org/cgi/content/full/2008/324/2?etoc
http://www.physorg.com/news125500956.html
http://www.eurekalert.org/pub_releases/2008-03/eu-yri032108.php