News reports of research into memory December 2009
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
December 2009
Learning styles challenged
A review of the research on learning styles finds that although numerous
studies have claimed to show the existence of different kinds of learners,
nearly all of the studies fail to satisfy key criteria for scientific validity —
in particular, by randomly assigning learners classified by their “style” to one
of several different learning methods (implicit in the idea of learning styles
is the concept that individuals differ in regard to what mode of instruction or
study is most effective for them). Of the few that did, some provided evidence
flatly contradictory to the meshing hypothesis (the most common hypothesis,
postulating that instruction is best provided in a format that matches the
preferences of the learner) and the few findings in line with the idea did not
assess popular learning-style schemes (71 different models of learning styles
have been proposed over the years). The reviewers do no contest that people have
preferences in how information is presented to them, or that people differ in
the degree to which they use different processing modes, or that there might be
untested learning styles that have significant effects. However, they argue that
the lack of evidence for the postulated interaction effect is good reason not to
spend limited education resources on this area that would better be devoted to
adopting other educational practices that have a strong evidence base.
The report was published in the December issue of Psychological Science in the
Public Interest. Full reference
http://www.eurekalert.org/pub_releases/2009-12/afps-lsd121609.php
Making student self-testing an effective study tool
A series of four experiments with 150 college students using Swahili-English
vocabulary words has revealed that
repeated retrieval was a very effective
learning strategy. However, when subjects were given control over their own
learning, they did not attempt retrieval as early or as often as they should to
promote the best learning. The findings are thought to reflect a powerful metacognitive illusion that occurs during self-regulated learning — namely, that
easy retrieval tends to make students believe they have “learned” it before the
material is properly mastered, leading to premature termination of the study
practice.
The findings appeared in the November issue of Journal of Experimental
Psychology: General. Full
reference
http://www.eurekalert.org/pub_releases/2009-12/pu-sse121009.php
Gender gap in math is culture-based
Data from the Trends in International Mathematics and Science Study and the
Programme for International Student Assessment, representing 493,495 students
ages 14-16 from 69 countries, have revealed only very small gender differences
overall, but marked variation when nations are compared. For example, there are
more girls in the top tier in countries such as Iceland, Thailand, and the
United Kingdom–and even in certain U.S. populations, such as Asian-Americans.
However, despite overall similarities in math skills, boys felt significantly
more confident in their abilities than girls did and were more motivated to do
well. Furthermore, although some studies have found more males than females
scoring above the 95th or 99th percentile, this gender gap has significantly
narrowed over time in the U.S. and is not found among some ethnic groups and in
some nations. Greater male variability with respect to mathematics, where it
exists, correlates with several measures of gender inequality.
The results were reported in the Proceedings of the National Academy of Sciences
and the January issue of Psychological Bulletin.
Full reference
Full reference
http://spectrum.ieee.org/at-work/education/math-quiz-why-do-men-predominate
http://www.physorg.com/news181915640.html
Video games may help visuospatial processing and multitasking
Another study has come out showing that expert video gamers have improved
mental rotation skills, visual and spatial memory, and multitasking skills. The
researchers conclude that training with video games may serve to reduce gender
differences in visual and spatial processing, and some of the cognitive declines
that come with aging.
The study appeared in the December issue of Current Directions in Psychological
Science. Full reference
http://www.eurekalert.org/pub_releases/2009-12/afps-rsa121709.php
Characteristics of age-related cognitive decline in semantic memory
A study involving 117 healthy elderly (aged 60-91) has found that, while
increasing age was associated with poorer memory for names of famous people, age
didn’t affect memory for biographical details about them. It also found that
names served as better cues to those details than faces did. A follow-up study
(to be published in Neuropsychologia) found that, in contrast, those with
mild
cognitive impairment and early Alzheimer’s showed not only an increased
inability to remember names, but also a decline in memory for biographical
details.
The findings were reported in the December issue of the Canadian Journal on
Aging. Full reference
http://www.eurekalert.org/pub_releases/2009-12/uom-whn121809.php
The importance of retrieval cues
An imaging study has revealed that it is retrieval cues that trigger activity
in the hippocampus, rather than, as often argued, the strength of the memory.
The study involved participants learning unrelated word pairs (a process which
included making up sentences with the words), then being asked whether various
familiar words had been previously seen or not — the words being shown first on
their own, and then with their paired cue word. Brain activity for words judged
familiar on their own was compared with activity for the same items when shown
with context cues. Increased hippocampal activity occurred only with cued
recall. Moreover, the amount of activity was not associated with familiarity
strength, and recollected items were associated with greater activity relative
to highly familiar items.
The paper was published in the December 29 issue of the Proceedings of the
National Academy of Sciences. Full
reference
http://www.eurekalert.org/pub_releases/2009-12/uot-dik120709.php
Ginkgo biloba does not slow rate of cognitive decline
Findings from the large, long-running Ginkgo Evaluation of Memory study have
sadly found no evidence for an effect of Ginkgo biloba on global cognitive
change and no evidence of effect on specific cognitive domains of memory,
language, attention, visuospatial abilities and executive functions. There was
also no evidence for treatment effects for any particular group (i.e. by age,
sex, race, education,
ApoE4 status, or baseline cognitive status). The
randomized, double-blind, placebo-controlled clinical trial involved 3069
seniors aged 72 to 96 years, with a median follow-up of 6.1 years. Those taking
the herb took a twice-daily dose of 120-mg. Earlier results from the study found
Ginkgo biloba did not reduce the incidence of dementia.
The study appeared in the December 23/30 issue of JAMA.
Full reference
http://www.eurekalert.org/pub_releases/2009-12/jaaj-gbd122309.php
Math theory explains children's cognitive development
Around age five, children begin to understand that if John is taller than
Mary, and Mary is taller than Sue, then John is also taller than Sue –
Transitive Inference. They also begin to understand that there are more fruit
than apples in a grocery store – Class Inclusion. Now a mathematical theory
explains why these two reasoning skills appear at the same time. It seems that
both involve the ability to apply two lines of thinking about a problem at the
same time, whereas younger children are limited to one. The theory provides a
good account not only of Transitive Inference and Class Inclusion, but also five
other forms of inference that are acquired around the same age: Matrix
Completion, Cardinality, Card Sorting, Balance Scale, and Theory of Mind.
The paper was published December 11 in the open-access journal PLoS
Computational Biology. Full
reference
Full text available at
http://dx.plos.org/10.1371/journal.pcbi.1000599
http://www.eurekalert.org/pub_releases/2009-12/plos-omr120709.php
New screening tool helps identify children at risk
An exam, called the NICU (neonatal intensive care unit) Network
Neurobehavioral Scale (NNNS), has been created to identify newborns who may have
problems with school readiness and behavior at age four. This opens up the
possibility of early intervention to prevent these problems. The screening exam
has been tested on 1248 babies, mostly black and on public assistance. Five
discrete behavioral profiles were reliably identified; the most extreme negative
profile was found in 5.8% of the infants. Infants with poor performance were
more likely to have behavior problems at age three, school readiness problems at
age four, and low IQ at 4 ½ — 40% had clinically significant problems
externalizing (impulsivity and acting out), internalizing (anxiety, depression,
withdrawn personalities), and with school readiness (delays in motor, concepts
and language skills), and 35% had low IQ.
The report was published in the December 7 issue of Pediatrics.
Full reference
http://www.eurekalert.org/pub_releases/2009-12/bu-nst120709.php
Children’s PTSD symptoms linked to poor hippocampus function
An imaging study comparing brain activity during a verbal memory task of 16
10- to 17-year-olds who had PTSD symptoms with a control group of 11 young
people, has found that while
hippocampal activity was similar in both groups
when the word list was presented, those with PTSD symptoms made more errors on
the recall part of the test and showed less hippocampus activity than control
subjects doing the same task. Additionally, those with the worst hippocampus
function were also most likely to experience a specific set of PTSD symptoms —
"avoidance and numbing", including difficulty remembering the trauma, feeling
cut off from others and lack of emotion. The research helps explain why
traumatized children behave as they do and could improve treatments.
The research was published online December 8 in the Journal of Pediatric
Psychology. Full reference
http://www.eurekalert.org/pub_releases/2009-12/sumc-bis120309.php
Getting the benefits of estrogen without the downside
We know estrogen helps learning and memory, but estrogen therapy also
increases cancer risk. That’s why the results of a mouse study are exciting. The
study found that estrogen acts through calpain, a
protein crucial to learning
and memory, and like adrenalin (which acts like a hormone in most of the body
but as a neurotransmitter in the brain), it does so as a neurotransmitter,
modulating synaptic transmission. The findings suggest drugs that target calpain
directly may provide the same cognitive benefits of estrogen therapy, without
the medical risks.
The study was published in the December 22 issue of the Proceedings of the
National Academy of Sciences.
Full reference
http://www.eurekalert.org/pub_releases/2009-12/uosc-cot120809.php
Mouse study points to possible treatment for chemobrain
A mouse study has found that four commonly used chemotherapy drugs disrupt
neurogenesis, and that the condition could be partially reversed with the growth
hormone IGF-1. Surprising the researchers, both the drugs which cross the
blood-brain barrier (cyclophosphamide and fluorouracil) and the two that don’t (paclitaxel
and doxorubicin) reduced neurogenesis, with fluorouracil producing a 15.4%
reduction, compared to 22.4% with doxorubicin, 30.5% with cyclophosphamide, 36%
with paclitaxel. A second study of a single high dose of cyclophosphamide, a
mainstay of breast cancer treatment, resulted in a 40.9% reduction.
Administration of the experimental growth hormone IGF-1 helped in all cases, but
was more effective with the high dose.
The report was published online 16 December in Cancer Investigation.
Full reference
http://www.eurekalert.org/pub_releases/2009-12/uorm-usr121709.php
Nerve-cell transplants help brain-damaged rats recover lost ability to learn
After destroying neurons in the
subiculum of 48 adult rats, some were given
hippocampal cells taken from newborn transgenic mice. On spatial memory tests
two months later, the rats given cell transplants performed as well as rats
which had not had their subiculums damaged; however, those without transplants
had significantly impaired performance. The new cells were found to have mainly
settled in the dentate gyrus, where they appeared to promote the secretion of
two types of growth factors, namely
BDNF and basic fibroblast growth factor (bFGF).
The report appeared in the December issue of Behavioral Neuroscience.
Full reference
http://www.eurekalert.org/pub_releases/2009-12/apa-nth120909.php
Amino acid diet helps brain-injured mice
In a study in which brain-injured mice received a cocktail of three branched
chain amino acids (BCAAs), specifically leucine, isoleucine and valine, in their
drinking water, those who received the cocktail showed normal learning ability
and normal activity in the hippocampus. BCAAs are crucial precursors of two
neurotransmitters—glutamate and
GABA, which function together to maintain an
appropriate balance of brain activity. Previously, it’s been found that people
with severe brain injuries showed mild functional improvements after receiving
BCAAs through an intravenous line. It’s suggested that receiving the BCAAs as a
dietary supplement could have a more sustained, measured benefit than that seen
when patients receive BCAAs intravenously, in which the large IV dose may flood
brain receptors and have more limited benefits.
The study appeared in the January 5 issue of the Proceedings of the National
Academy of Sciences. Full reference
http://www.eurekalert.org/pub_releases/2009-12/chop-waa120209.php
HIV-related memory loss linked to Alzheimer's protein
More than half of HIV patients experience memory problems and other cognitive
impairments as they age. Now analysis of biomarkers in the
cerebrospinal fluid
have demonstrated how HIV-related cognitive impairment is like
Alzheimer's-related dementia, and how it is different. The comparison of 49 HIV
patients with cognitive impairments (average age 48), 21 HIV patients with
normal cognitive function (average age 43), 68 patients with mild Alzheimer's
(average age 74) and 50 normal, healthy controls (average age 50), found
similarly low levels of
amyloid beta in those HIV patients with cognitive
impairments and those with Alzheimer’s — surprising researchers, and confirming
an earlier study. Unlike the HIV patients however, those with mild Alzheimer's
had significantly higher levels of
tau.
The report appeared in the December 8 issue of Neurology.
Full reference
http://www.eurekalert.org/pub_releases/2009-12/wuso-hml120209.php
