News reports of research into memory January 2005
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January 2005
Older people with the 'Alzheimer's gene' find it harder to remember intentions
It has been established that those with a certain allele of a
gene called ApoE have a much greater risk of developing Alzheimer’s
(those with this allele on both genes have 8 times the risk; those
with the allele on one gene have 3 times the risk). Recent studies
also suggest that such carriers are also more likely to show signs
of deficits in episodic memory – but that these deficits are quite
subtle. In the first study to look at prospective memory in seniors
with the “Alzheimer’s gene”, involving 32 healthy, dementia-free
adults between ages of 60 and 87, researchers found a marked
difference in performance between those who had the allele and those
who did not. The results suggest an exception to the thinking that
ApoE status has only a subtle effect on cognition.
The research appeared in the January issue of
Neuropsychology.
Full reference
Full text of the article is available at:
http://www.apa.org/journals/releases/neu19128.pdf.
http://www.eurekalert.org/pub_releases/2005-01/apa-opw011805.php
Moderate alcohol intake may reduce cognitive decline in older women
Two recent large-scale epidemiological studies have come out
recently with similar findings. Data from the Women's Health
Initiative Memory Study (involving 4,461 women aged 65 to 79 years)
has revealed that women who reported having one or more alcohol
drinks daily had a 40% lower risk of significant declines in
cognitive function over time, compared to women who reported no
alcohol intake. It is possible that moderate alcohol intake may
reduce the risk for narrowed vessels in the brain. In addition,
alcohol may decrease the formation of plaque that is associated with
Alzheimer's disease.
Data from the Nurses' Health Study, begun in 1976 and involving
12,480 women, now aged between 70 and 81 years old, has found that
women who had the equivalent of one drink a day had a 23% lower risk
of becoming mentally impaired during a two-year period, compared
with non-drinkers. It made no significant difference whether they
drank beer or wine.
The first study was reported in the February 1 issue of the
American Journal of Epidemiology.
Full reference
The study was reported in the January 20 issue of the
New England Journal of Medicine.
Full reference
http://www.eurekalert.org/pub_releases/2005-01/wfub-mai012105.php
(1st study)
http://www.nature.com/news/2005/050117/full/050117-10.html
(2nd study)
Diet, exercise, stimulating environment helps old dogs learn
A new study of beagles provides more evidence that diet and
mental stimulation are important in reducing or preventing
age-related cognitive decline. The study, involving 48 older beagles
(aged 7 to 11), compared four combinations of behavioral enrichment
(regular exercise and lots of mental stimulation) and
supplementation of diet with antioxidants had on a beagle's ability
to learn: regular diet and regular experience; regular diet and
enriched experience; regular experience and an enriched diet; and
enriched diet and an enriched experience. The study followed the
beagles over two years. Those in the groups with either an enriched
diet or enriched environment did better than those without either,
but those who had both the enriched diet and an enriched environment
did noticeably better than all the rest.
The study was published in the January 2005 issue of
Neurobiology of Aging.
Full reference
http://www.eurekalert.org/pub_releases/2005-01/uot-mtc011705.php
http://www.eurekalert.org/pub_releases/2005-01/nioa-des011805.php
IQ-related brain areas may differ in men and women
An imaging study of 48 men and women between 18 and 84 years old
found that, although men and women performed equally on the IQ
tests, the brain structures involved in intelligence appeared
distinct. Compared with women, men had more than six times the
amount of intelligence-related
gray matter, while women had about nine times more white matter
involved in intelligence than men did. Women also had a large
proportion of their IQ-related brain matter (86% of white and 84% of
gray) concentrated in the
frontal lobes, while men had 90% of their IQ-related gray matter
distributed equally between the frontal lobes and the
parietal lobes, and 82% of their IQ-related white matter in the
temporal lobes. The implications of all this are not clear, but
it is worth noting that the volume of gray matter can increase with
learning, and is thus a product of environment as well as genes. The
findings also demonstrate that no single neuroanatomical structure
determines general intelligence and that different types of brain
designs are capable of producing equivalent intellectual
performance.
The study was published online January 16 in
NeuroImage.
Full reference
http://health.yahoo.com/news/57792
http://www.eurekalert.org/pub_releases/2005-01/uoc--iim012005.php
http://www.sciencedaily.com/releases/2005/01/050121100142.htm
Faces must be seen to be recognized
In an interesting new perspective on face recognition, a series
of perception experiments have revealed that identifying a face
depends on actually seeing it, as opposed to merely having the image
of the face fall on the retina. In other words, attention is
necessary.
The study was published in the January 6 issue of
Neuron.
Full reference
http://www.eurekalert.org/pub_releases/2005-01/cp-fmb122904.php
Imaging reveals brain abnormalities in ADHD children
A new type of brain imaging called diffusion tensor imaging (DTI)
has provided some suggestive evidence about brain abnormalities in
children diagnosed with ADHD. Abnormalities were found in the
white-matter pathways in the
frontal cortex,
basal ganglia, brain stem and
cerebellum—areas that are involved in regulating attention,
impulsive behavior, motor activity, and inhibition, which are all
related to ADHD symptoms.
This research was presented at the 2004 annual meeting of the
Radiological Society of North America.
http://www.sciencentral.com/articles/view.htm3?article_id=218392460
New theory challenges current view of how brain stores long-term memory
The current view of long-term memory storage is that, at the
molecular level, new proteins are manufactured (a process known as
translation), and these newly synthesized proteins subsequently
stabilize the changes underlying the memory. Thus, every new memory
results in a permanent representation in the brain. A new theory of
memory storage suggests instead that there is no permanent
representation. Rather, memories are copied across many different
brain networks. The advantage is that it is a highly flexible
system, enabling rapid retrieval even of infrequent elements.
The theory suggests that the brain stores long-term memory by
rapidly changing the shape of proteins already present at those
synapses activated by learning. The theory explains a number of
phenomena that are not properly answered by the existing theory. The
theory doesn’t disagree with the view that it is the synapse that is
modified in response to learning; the disagreement concerns how that
synaptic modification occurs. Current theory says it is brought
about by recently synthesized proteins; the new theory suggests that
learning leads to a post-synthesis (post-translational) synaptic
protein modification that results in changes to the shape, activity
and/or location of existing synaptic proteins. It is suggested that
long-term memory storage relies on a positive-feedback rehearsal
system that continually updates or fine-tunes post-translational
modification of previously modified synaptic proteins, thus allowing
for the continual modifications of memories.
The theory was outlined the in the January issue of
Trends in Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2005-01/nu-ntc011405.php
http://www.sciencedirect.com/science/journal/01662236
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