News reports of research into memory September 2001
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You can find links to the journals referred to on this site here: Journal links
September 2001
The study locating our sense of identity in the right frontal lobe was reported in May, when it was presented at the American Academy of Neurology’s Annual Meeting. The paper has now appeared in the September 11th issue of Neurology.
The way people go about controlling their reactions to emotional
events affects their memory of the event. In a series of experiments designed to
assess the effect of suppressing the expression of emotion, it was found that,
when people were shown a video of an emotional event and instructed not to let
their emotions show, they had poorer memory for what was said and done than did
those people who were given no such instructions. However, when shown slides of
people who had been injured, people in both groups were equally good at picking
which in an array of subtly different versions of each slide had been shown
earlier - but when prompted to recall information that had been presented
verbally with each slide, those in the suppression group again remembered fewer
details. People who were asked to adopt the neutral attitude of a medical
profession however, performed better than the control group on nonverbal recall,
indicating the regulation of emotions via reappraisal was not associated with
any memory impairment. These experimental results were supported by a
naturalistic study.
The study was reported in the September issue of the Journal of Personality and
Social Psychology.
Full
reference
Full text of this article is available at http://www.apa.org/journals/psp/psp793410.html
http://www.sciencedaily.com/releases/2000/09/000913203335.htm
Susumu Tonegawa and colleagues at the Massachusetts Institute of Technology and the Vollum Institute
have released the first of a series of studies illuminating how short-term memories are turned into long-term ones via
consolidation, how different types of learning occurs in unexpected ways, and how memory recall occurs.
In this first study, the researchers eliminated the function of a single
enzyme in a restricted memory-related region in the brains of mice, and thus
showed that the enzyme is important in consolidating long-term memories. While
this enzyme (calcium-calmodulin dependent kinase (CaMKIV)), has been implicated
in the process of establishing long-term memories, previous research has been
inconclusive because the techniques used to knock out the enzyme were so global.
A series of behavioral experiments led the researchers to conclude that the CaMKIV pathway was primarily
involved in memory consolidation and retention. However, memory consolidation was not
completely extinguished, suggesting that there may be parallel signaling pathways involved in consolidation, or that there may have been incomplete
knockout of CaMKIV activity.
The report was published in the September 21, 2001, issue of Cell.
Full
reference
http://www.hhmi.org/news/tonegawa.html
http://news.bmn.com/news/story?day=010921&story=1
http://www.eurekalert.org/pub_releases/2001-09/hhmi-rfe092001.php
Neuroscientists can't agree on whether the brain uses
specific regions to distinguish specific objects, or patterns of activity from
different regions. The debate over how the brain deals with visual information
has been re-ignited with apparently contradictory findings from two research
groups. One group has pinpointed a distinct region in the brain that responds
selectively to images of the human body, while another concludes that the
representations of a wide range of image categories are dealt with by
overlapping brain regions. (see below)
http://news.bmn.com/news/story?day=010928&story=2
Cognitive neuroscientists have identified a new area of
the human brain that responds specifically when people view images of the human
body. They have named this region of the brain the 'extrastriate body area' or
'EBA'. The EBA can be distinguished from other known anatomical subdivisions of
the visual cortex. However, the EBA is in a region of the brain called the
posterior superior temporal sulcus, where other areas have been implicated in
the perception of socially relevant information such as the direction that
another person's eyes are gazing, the sound of human voices, or the inferred
intentions of animate entities.
Their findings are reported in the 28 September issue of Science.Full
reference
National Institute of Mental Health (NIMH) scientists
have shown that they can tell what kind of object a person is looking at — a
face, a house, a shoe, a chair — by the pattern of brain activity it evokes.
Earlier NIMH fMRI studies had shown that brain areas that respond maximally to a
particular category of object are consistent across different people. This new
study finds that the full pattern of responses — not just the areas of maximal
activation — is consistent within the same person for a given category of
object. Overall, the pattern of fMRI responses predicted the category with 96%
accuracy. Accuracy was l00% for faces, houses and scrambled pictures.
The study appeared in the September 28 issue of Science.
Full
reference
http://www.eurekalert.org/pub_releases/2001-09/niom-bsp092601.php
http://www.sciencemag.org/cgi/content/abstract/293/5539/2425
You can see images from one subject at: http://www.nimh.nih.gov/events/images/topography800.jpg.
Learning difficulties, including problems with
numeracy, are common in Western populations. Many children with learning
difficulty are survivors of preterm birth. Although some of these children have
neurological disabilities, many are neurologically normal. A neuroimaging study
of neurologically normal adolescent children who had been born preterm at 30
weeks gestation or less found an area in the left parietal lobe where children
without a deficit in calculation ability have more grey matter than those who do
have this deficit.
The study appeared in Brain.
Full
reference
http://brain.oupjournals.org/cgi/content/abstract/124/9/1701
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1512000/1512664.stm
http://www.independent.co.uk/story.jsp?story=90945
http://www.independent.co.uk/story.jsp?story=90945
http://www.independent.co.uk/story.jsp?story=90945
A new study suggests that hypnosis doesn't help
people recall events more accurately - but it does tend to make people more
confident of their inaccurate memories. Researchers asked college students,
including some who were under hypnosis, to give the dates of 20 national and
international news events from the past 11 years. Those who were hypnotized were
no more accurate than others in choosing the correct dates. However, those who
were hypnotized were more reluctant to change their answers when they were told
they might be wrong. Joseph Green, co-author of the study and associate
professor of psychology at Ohio State University's Lima campus, said the results
of the new study don't mean that hypnosis has no value. Any kind of technique
used to retrieve memories - including the use of diaries or drugs - will produce
inaccurate memories. However, the difference is that people tend to have more
faith in hypnosis than they do in other memory techniques.
The results of this study were presented in San Francisco at the annual meeting
of the American Psychological Association on August 26.
Reference
http://www.eurekalert.org/pub_releases/2001-08/osu-hmg082201.php
A miniature head-mounted microscope,
designed for use on rats, could monitor activity in individual brain cells, says
the US team that developed it. The technological breakthrough should, for
example, give scientists an unprecedented insight into how memories are formed.
Full
reference
http://www.newscientist.com/news/news.jsp?id=ns99991353
Because they are hard to forget,
surprises can help us learn. Now scientists have identified a part of the brain
that may be involved in learning from surprises. A team led by Dr. Paul C.
Fletcher at the University of Cambridge monitored the brain activity in a group
of volunteers who were participating in a simulation exercise. The participants
pretended to work at drug companies and were asked to predict whether a
particular fictitious drug would trigger a particular fictitious syndrome. In
the early phase of the study, when the participants were not familiar with the
effects of the various drugs, imaging tests detected high levels of activity in
this part of the brain. As the volunteers became familiar with the effects of
the drugs, so that they were no longer surprised by the results, activity in the
dorsolateral prefrontal cortex declined, but later in the study, this region
became more active when the participants were surprised by unexpected responses.
The article was recently published in the online edition of Nature
Neuroscience (registration required).
Full
reference
Source
memory is memory for the broad contextual aspects surrounding an event, such as who was
speaking, or whether you learned something from a book or TV. Previous research
has found that it is in this aspect of memory that older
people tend to be particularly poor. In a study that compared older individuals
with undergraduates, it was found that those who performed above average on
frontal-lobe tests, showed no significant impairment of source memory,
regardless of age. Those with below-average performance, tended to have impaired
source memory (as a group). In other words, source-memory problems are not an
inevitable consequence of aging, as has been widely thought, but rather are a
function of frontal-lobe efficiency. The proportion of older adults who
experience frontal-lobe decline, at what ages, and to what degree, is unknown at
this time.
What’s more, when researchers required people to consider the
relation between an item and its context (source), age differences in memory
performance completely disappeared, suggesting older adults can learn strategies
to remember the context better.
The report appears in the September issue of the Journal of Experimental
Psychology: Learning, Memory, and Cognition, and is available online at: http://www.apa.org/journals/xlm/press_releases/september_2001/xlm2751131.html
Full
reference
http://www.eurekalert.org/pub_releases/2001-09/apa-ada083101.php
Using a newly developed technique, University
of Chicago researchers have manipulated one of the signaling proteins in the
developing mouse brain and found such manipulations cause radical changes in the
cortex. Fibroblast Growth Factor 8 (FGF8), a member of a family of signaling
proteins involved in forming other structures in the embryo, is normally found
near the front of the developing cortex. Using a new microsurgical technique,
the researchers were able to manipulate the amount and position of this
signaling protein in the embryo and look for changes in the cortical pattern
much later. The researchers increased the amount of the signaling protein in its
normal position, decreased it by inserting a gene for a receptor able to soak up
the protein, or expressed it in a new position. Each manipulation profoundly
affected cortical area pattern. "Most dramatic, when a new source of the
signaling protein was generated close to the back of the embryonic cortex, the
whole program changed." The generation of a new cortical area by a
molecular manipulation has not been seen before and may provide a clue about how
the cerebral cortex changes in evolution. One way that evolution seems to
generate more functionally complex brains is by adding new areas to the cortex.
The paper appeared In the September 20, 2001 edition of Science Express.
Full
reference
http://www.eurekalert.org/pub_releases/2001-09/uocm-anm091801.php
How can we help kids cross streets more safely?
Improving their abilities to concentrate and switch their attention may be part
of the answer. British psychologists studied these two central attentional
skills in children ages four to 10 in relation to how safely they crossed the
street. The results suggest that children who can concentrate and switch their
attention better may cross more safely. The study used a computer game to gauge
the “attention switching” skills of 101 children. Distractability and
impulsivity were also measured, in a representative sample of 35 children. These
35 children were then covertly videotaped crossing streets (with their parents).
Attentional skills significantly correlated with pedestrian behavior, in
different ways. Children who were better at switching attention on the Frog Game
were more likely to look at traffic when about to cross a road. Children who
were less able to concentrate in the lab when challenged by a distraction also
tended to be more impulsive; children rated as more impulsive tended to cross
the road in a less controlled way. The biggest improvements seemed to come
between the group of four-five year olds and the group of five-six year olds,
the difference between preschool and kindergarten age. Finally, concentration,
but not switching, correlated with impulsivity, suggesting that these two skills
(concentration and attention switching) represent distinct aspects of attention.
The findings appear in the September issue of the Journal of Experimental
Psychology: Applied.
Full
reference
http://www.eurekalert.org/pub_releases/2001-09/apa-cwc091001.php
Researchers in Spain have isolated for the first time a
by-product of the illicit drug Ecstasy that is believed to cause some of the
brain damage associated with the drug. They believe their finding will help them
measure, with greater precision, the long-term neurotoxicity of Ecstasy in human
users.
The report appeared in the September issue of Chemical Research in
Toxicology, a peer-reviewed journal of the American Chemical Society.
Full
reference
http://www.eurekalert.org/pub_releases/2001-08/acs-ecm081301.php
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