News reports of research into memory February 2008
For index of all headlines, go to News & Views main page
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You can find links to the journals referred to on this site here: Journal links
February 2008
More study needed to determine if gingko biloba helps memory
A three-year study involving 118 people age 85 and older
with no memory problems found no significant difference in the development of
memory problems during the study between those who took ginkgo biloba extract
three times a day and those who took a placebo. However, when adherence was
taken into account, it was found that those who reliably took the
supplement had a 68% lower risk of developing mild memory problems than those
who took the placebo. But those taking ginkgo biloba were more likely to have a
stroke or transient ischemic attack. Further studies are needed.
The study was published online February 27 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/aaon-dgb022208.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.
The study appeared in the February 17 issue of Nature Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/nioa-shi021508.php
Gender differences in memory
A series of experiments looking at memory performance in
men and women has revealed that women did better at verbal episodic memory
tasks, such as remembering words, objects, pictures or everyday events, and men
outperformed women in remembering symbolic, non-linguistic information, known as
visuospatial processing. But women were again better on tasks that require both
verbal and visuospatial processing, such as remembering the location of car
keys. Women were also better at remembering faces, especially female faces. They
also remembered androgynous faces presented as female more accurately than the
androgynous faces presented as male, suggesting the reason is that women pay
more attention to female than to male faces. Women also performed better than
men in tasks requiring little to no verbal processing, such as recognition of
familiar odors. But environmental factors, such as education, seem to influence
the magnitude of these sex differences.
The findings appeared in the February edition of Current
Directions in Psychological Science.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/afps-tgr022008.php
A nap can help you learn
A study of 33 younger adults (average are 23) has found
that a 45 minute afternoon nap (containing only non-REM sleep) improved
performance on 3 different declarative memory tasks, but only when the subjects
had reached a certain level of performance during training.
The study was published in the February 1 issue of SLEEP.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/aaos-jss012808.php
REM sleep deprivation reduces neurogenesis
And in another sleep study, rats deprived of REM sleep for
four days showed reduced cell proliferation in the
dentate gyrus of the
hippocampus, where most adult
neurogenesis takes place. The finding indicates
that REM sleep is important for brain plasticity.
The study was published in the February 1 issue of SLEEP.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/aaos-fdo012808.php
Memory loss becoming less common in older Americans
A new nationally representative study involving 11,000
people shows a downward trend in the rate of cognitive impairment among people
aged 70 and older, from 12.2% to 8.7% between 1993 and 2002. It’s speculated
that factors behind this decline may be that today’s older people are much
likelier to have had more formal education, higher economic status, and better
care for risk factors such as high blood pressure, high cholesterol and smoking
that can jeopardize their brains. In fact the data suggest that about 40% of the
decrease in cognitive impairment over the decade was likely due to the increase
in education levels and personal wealth between the two groups of seniors
studied at the two time points. The trend is consistent with a dramatic decline
in chronic disability among older Americans over the past two decades.
The study was published online ahead of print in Alzheimer’s and Dementia.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/uomh-mla021808.php
Stroke risk factors may signal faster cognitive decline in elderly
Analysis of the stroke risks of over 17,000 people aged 45
and older (average 65.9) has found that a higher stroke risk score was
associated with a significantly higher rate of cognitive decline. The study also
identified three specific risk factors significantly associated with memory loss
– high systolic blood pressure, diabetes, and left ventricular hypertrophy.
The findings were reported at the American Stroke
Association’s International Stroke Conference 2008.
http://www.eurekalert.org/pub_releases/2008-02/aha-srf021408.php
Smoking marijuana impairs cognitive function in MS patients
A study of 140 Canadians with multiple sclerosis has found
that those (10) who were defined as current marijuana users performed 50% slower
on tests of information processing speed compared to matched MS patients who did
not smoke marijuana. There was also a significant association between smoking
marijuana and emotional problems such as depression and anxiety.
The research was published online February 13 in Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/aaon-smi020508.php
Listening to music improves stroke patients' recovery
A Finnish study involving 60 patients who had suffered a
stroke of the left or right hemisphere middle cerebral artery (MCA) has found
that if stroke patients listened to music for a couple of hours a day, their
verbal memory and focused attention recovered better and they had a more
positive mood than patients who did not listen to anything or who listened to
audio books. Patients were randomly assigned to a music listening group, a
language group or a control group. During the next two months the music and
language groups listened daily to music they chose themselves or to audio books
respectively, while the control group received no listening material. All groups
received standard stroke rehabilitation. Three months after the stroke, verbal
memory improved from the first week post-stroke by 60% in music listeners, by
18% in audio book listeners and by 29% in non-listeners. Similarly, focused
attention improved by 17% in music listeners, but no improvement was observed in
audio book listeners and non-listeners. The differences were essentially the
same six months after the stroke. The music listening group also experienced
less depressed and confused mood than the patients in the control group.
The research was published online 20 February in Brain.
Full reference
http://www.eurekalert.org/pub_releases/2008-02/uoh-ltm021508.php
http://news.yahoo.com/s/nm/20080220/music_nm/stroke_music_dc
Children's under-achievement could be down to poor working memory
A survey of over three thousand children has found that 10%
of school children across all age ranges suffer from poor working memory
seriously affecting their learning. However, poor working memory is rarely
identified by teachers, who often describe children with this problem as
inattentive or as having lower levels of intelligence. The researchers have
developed a new tool, a combination of a checklist and computer programme called
the Working Memory Rating Scale, that enables teachers to identify and assess
children's memory capacity in the classroom from as early as four years old. The
tool has already been piloted successfully in 35 schools across the UK, and is
now widely available. It has been translated into ten foreign languages.
http://www.physorg.com/news123404466.html
http://www.eurekalert.org/pub_releases/2008-02/du-cuc022608.php
Different educational approaches appropriate for boys and girls?
An imaging study of some 50 children aged 9 to 15 revealed
that girls showed significantly greater activation of the language areas of the
brain when doing a language task than did boys. The boys showed greater
activation of the specific sensory brain areas--visual or auditory--required by
the task. This pattern suggests that girls rely on a supramodal language
network, whereas boys process visual and auditory words differently. This
difference may reflect the fact that males take longer to mature than females,
rather than a lifelong gender difference, but it does have implications for
education.
The study appeared online 4 January in Neuropsychologia.
Full reference
http://sciencenow.sciencemag.org/cgi/content/full/2008/307/1?etoc
Effect of schooling on achievement gaps within racial groups
Analysis of data from a national sample (U.S.) of 8,060
students, collected at four points in time, starting in kindergarten and ending
in the spring of fifth grade, has found evidence that education has an impact in
closing the achievement gap for substantial numbers of children. High-performing
groups in reading were found among all races. About 30% of European Americans,
26% of African Americans and 45% of Asian Americans were in high-achieving
groups by the spring of fifth grade — these groups included approximately 23% of
African American children and 36% of Asian children who caught up with the
initial group of high achievers over time. Only around 4% of European American
students were in catch-up groups, because a higher percentage of European
Americans started kindergarten as high achievers in reading. The situation was
different for Hispanic students, however. By the end of fifth grade, just over
5% of Hispanic children were high achievers in reading, while the remainder
tested in the middle range. There were no low achievers and no catch-up groups.
A different pattern was found in math. Only 17% of European American students
were high-achievers in math by the end of fifth grade, including 13% who started
kindergarten at a lower achievement level and caught up over time. About 18% of
Asian Americans were high-achievers at the end of fifth grade (11% catch-up).
Only 0.3% of African Americans were high achievers at the end of fifth grade,
and 26% were medium-high achievers. But about 16% of Hispanics were high
achievers in math. There were no catch-up groups for either the African
Americans or the Hispanics. This suggests that current schooling doesn't have as strong
an impact on math achievement as it does in reading.
The study was presented in Washington, D.C. at the annual meeting of the Society
for Research on Educational Effectiveness.
http://www.physorg.com/news123859991.html
What distinguishes human from animal cognition
Studies of animal cognition have increasingly whittled away
at the ‘specialness’ of human cognition. A new hypothesis now suggests that
there are four key differences in human and animal cognition: the ability to
combine and recombine different types of information and knowledge in order to
gain new understanding; to apply the same "rule" or solution to one problem to a
different and new situation; to create and easily understand symbolic
representations of computation and sensory input; and to detach modes of thought
from raw sensory and perceptual input.
The work was presented at the annual meeting of the
American Association for the Advancement of Science.
http://www.physorg.com/news122466244.html
http://www.eurekalert.org/pub_releases/2008-02/hu-spf021408.php
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