News reports of research into memory September 2004
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
September 2004
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.
The study is to be published in the Journal of
Experimental Social Psychology.
http://www.eurekalert.org/pub_releases/2004-08/uons-era082004.php
New technique sheds light on autobiographical memory
A new technique for studying autobiographical memory has revealed
new findings about autobiographical memory, and may prove useful in
studying age-related cognitive impairment. Previous inconsistencies
between controlled laboratory studies of memory (typically, subjects
are asked to remember items they have previously seen in the
laboratory, such as words presented on a computer screen) and
studies of autobiographical memory have seemed to indicate that the
brain may function differently in the two processes. However, such
differences might instead reflect how the memories are measured. In
an effort to provide greater control over the autobiographical
memories, volunteer subjects were given cameras and instructed to
take pictures of campus scenes. The subjects were also instructed to
remember the taking of each picture as an individual event, noting
the physical conditions and their psychological state, such as their
mood and associations with the subject of the images. The subjects
were then shown a selection of campus photos they had not taken.
While their brains were scanned, they were then shown a mix of their
own photos with those they had not taken, and asked to indicate
whether each photo was new, seen earlier in the lab, or one they had
taken themselves. The researchers found that recalling the
autobiographical memories activated many of the same brain areas as
laboratory memories (the
medial temporal lobe and the
prefrontal cortex); however, they also activated brain areas
associated with "self-referential processing" (processing
information about one's self), and regions associated with retrieval
of visual and spatial information, as well as showing a higher level
of activity in the recollection areas in the
hippocampus.
The report will appear in the November issue of the
Journal of Cognitive Neuroscience.
http://www.eurekalert.org/pub_releases/2004-09/du-blm092904.php
Effect of expectations on older adults’ memory performance
A study involving 193 participants and two experiments, each with
a younger (17 – 35 years old) and older (57 – 82 years old) group of
adults, has investigated how negative stereotypes about aging
influences older adults' memory. Participants were exposed to
stereotype-related words in the context of another task (scrambled
sentence, word judgment) in order to prime positive and negative
stereotypes of aging. Results show memory performance in older
adults was lower when they were primed with negative stereotypes
than when they were primed with positive stereotypes. Age
differences in memory between young and older adults were
significantly reduced following a positive stereotype prime, with
young and older adults performing at almost identical levels in some
situations.
The report appeared in the September issue of
Psychology and Aging.
Full reference
Full text is available at
http://www.apa.org/journals/pag/press_releases/september_2004/pag193.html
http://www.eurekalert.org/pub_releases/2004-09/apa-se090704.php
Walking may protect elderly from dementia
A study of more than 2,200 Japanese-American men between the ages
of 71 and 93 has found that elderly men who are sedentary or walk
less than a quarter of a mile per day are nearly twice as likely to
develop dementia and Alzheimer's disease compared to men who walk
more than two miles per day. Those who walked less than a mile (and
more than quarter of a mile) a day also showed a significantly
greater risk of dementia than those walking more than two miles a
day.
The study was published in the Sept. 22 issue of the
Journal of the American Medical Association.
Full reference
http://www.eurekalert.org/pub_releases/2004-09/uovh-wmp091504.php
Physical activity associated with better mental functioning in older women
Since 1986, 18,766 women, aged 70 to 81 years, have been
questioned on their physical activity in biennial questionnaires.
The women were divided into five groups depending on their average
energy expenditures. Those in the highest activity grouping had a
20% lower risk of cognitive impairment than women in the lowest.
Women who walked at an easy pace for at least 1.5 hours per week had
higher cognitive scores than those who walked less than forty
minutes per week.
The report was published in the September 22 issue of
JAMA.
Full reference
http://www.eurekalert.org/pub_releases/2004-09/jaaj-pai091604.php
Drinking too much alcohol, and not enough, increases risk of cognitive impairment
In Finland, researchers re-examined 1018 participants from a
study of 1464 men and women aged 65-79 studied in 1972 or 1977. They
found that participants who drank
no alcohol in midlife as well as those who drank alcohol
frequently were twice as likely to have mild cognitive
impairment in old age compared to those who drank alcohol
infrequently. The effect of alcohol was however modified by the
presence of the apolipoprotein e4 allele (implicated in
dementia risk). People who were carriers of the
apolipoprotein e4 allele had an increased risk of
dementia with increasing alcohol consumption, with carriers of the
gene significantly reducing their risk by never drinking.
The study was reported in the September 4 issue of the
British Medical Journal.
Full reference
Why cardiac arrest may hinder ability to learn certain tasks
Cardiac arrest can take a particularly harsh toll on the
hippocampus, the area of the brain that plays a critical role in
memory and navigation. A new mouse study found that mice that had
had a (surgically induced) heart attack had far more difficulty
learning a new spatial task than did healthy mice (controls were
given the surgery, but didn’t have a cardiac arrest induced). Mice
in the heart attack group spent about eight minutes in cardiac
arrest – enough time to stop the flow of oxygen to the brain.
Analysis of the brain tissue found an overall 18% decrease in
dendritic spine density in the
hippocampus
in the cardiac arrest mice compared to the control mice (dendritic
spines are projections from neurons involved in sending signals
throughout the central nervous system and the body). The researchers
are now looking at how different types of social interactions
influence the number and health of neurons that survive a heart
attack.
The study appeared in the October issue of the
European Journal of Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2004-09/osu-cam092904.php
Cognitive function of alcohol abuse patients may influence treatment outcome
Years of heavy alcohol consumption are known to impair many
abilities generally referred to as “executive functions.” Such
functions include judgment, problem solving, decision making,
planning, and social conduct. But alcohol affects executive
functioning both chronically and acutely. New research has found
that alcohol abuse patients show significant deficits in executive
functioning (specifically, abstract reasoning, memory
discrimination, and effectiveness on timed tasks) during the
critical first weeks of abstinence. The finding has implications for
treatment programs, as the early phases of most treatment programs
for alcohol abusers commonly require working in groups, making plans
for the future, inhibiting behaviors related to their addiction, and
remembering specific things. It is suggested that clinicians should
scale down their expectations of what patients can do until more of
their executive functioning comes back. The researchers are now
intending to explore how long it takes the majority of people to
regain most of their executive functioning.
The findings were published in the September issue of
Alcoholism: Clinical & Experimental Research.
Full reference
http://www.eurekalert.org/pub_releases/2004-09/ace-cco090504.php
http://www.eurekalert.org/pub_releases/2004-09/dumc-cfo091004.php
Dyslexia doesn't have a universal biological cause
While most of the latest research focuses on the biological causes
of dyslexia, a new study reveals that the disorder affects the
brains of Chinese and English speakers differently, suggesting that
the neural basis of reading differs depending on the nature of the
writing system. The findings have enormous implications for helping
impaired readers in China, where 2% to 7% of children are dyslexic.
The study also highlights the importance of paying attention to
differences in languages, even languages as similar as English and
Italian. It has been shown that the degree of impairment when
reading can differ depending on the language.
The study appeared in the 2 September issue of
Nature.
Full reference
http://msnbc.msn.com/id/5888011/
Another clue to the evolution of the human brain
A new study suggests that the birth of a gene that fueled
neurotransmission may have been a key advance in the evolution of
the hominoid brain. GLUD2, a gene gene involved in glutamate
metabolism, is found in humans and apes, but not in Old World
monkeys, indicating that the gene appeared after monkeys and
hominoids went their separate ways (some 23 million years ago), but
before the gibbon lineage split from humans and great apes around 18
million years ago. Over time, GLUD2 acquired two amino acid changes
that increased glutamate flux, possibly enhancing cognitive function
in the hominoid brain.
The study appeared in the October issue of
Nature Genetics.
Full reference
http://www.biomedcentral.com/news/20040920/02
Evidence other animals remember in the same way humans do
In 350 B.C., Aristotle, in his seminal treatise on the subject,
described remembering as having two forms: familiarity and
recollection. Of these, he considered recollection to be a purely
human condition. A rat study has now provided the first evidence
that rats use recollection when recognizing items they have recently
experienced. In addition, the researchers show that rodents'
capacity for recollection-like memory retrieval depends on the
hippocampus, the same structure believed to be involved in
recollection in humans.
Their findings are published in the September 9 issue of
Nature.
Full reference
http://www.eurekalert.org/pub_releases/2004-09/bu-wam090804.php
Now available as a downloadable ebook!
