Predicting memory recall through imaging

Posted by rpcman on August 24, 1998 at 12:25:23:

I found the following science news item to be particularly fascinating (partly because I'm currently reading Conversations With Neil's Brain ) and thought some of you might be interested and/or have comments...

05:44 PM ET 08/20/98

Imaging shows just how the brain remembers

(Updates with comments from researcher)
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Researchers said Thursday they have
started to pin down just where in the brain things get
remembered.
Using a new technology known as functional neuroimaging,
they said they could watch a person's brain as he or she looked
at a picture or word and predict whether the person would later
remember what had been seen or read.
They said their method might provide a good test for
Alzheimer's disease and other brain damage that affects memory.
``MRI (magnetic resonance imaging) has been around for a
long time to look at structural images of the body and the
brain, but recently we been able to look at activity,''
University of California Irvine graduate student James Brewer,
who conducted the study, said in a telephone interview.
The MRI can be used to look at blood oxygenation levels, and
thus at what areas of the brain are being used.
Brewer, working with associate psychology professor John
Gabrieli and colleagues, showed a group of volunteers a batch of
photographs.
They told them simply to determine whether the scenes showed
were indoors or outside. Half an hour later, the four volunteers
got a ``pop quiz'' in which they were shown the same pictures
plus 32 new ones.
The researchers imaged each person's brain as he or she
looked at the pictures.
There were variations in who could remember what, but what
kind of activity was going on the brain, and where, predicted
whether someone would remember the picture.
Especially important were the right frontal and bilateral
parahippocampal regions, they wrote in a report in the journal
Science.
``The right frontal region seems to be involved in
processing nonverbal material,'' Brewer said.
When the parahippocampal region is damaged, patients have
major memory problems. For example in Alzheimer's, which damages
this region, people can remember their childhoods but not recent
events.
Anthony Wagner of Harvard University, who recently studied
with Gabrieli, did a similar test with words.
People who analyzed words based on their meanings, rather
than their appearance such as whether they were written in upper
or lower-case, had greater brain activity and were more likely
to remember the words, Wagner reported.
In this case, it was the left prefrontal and temporal
cortices that mattered.
The next step, Brewer said, is to try out the tests in
people at risk of Alzheimer's -- there are several genes
associated with the brain-destroying disease -- and see if they
might predict who will get the disease.
``We're scanning an Alzheimer's patient tonight to see if we
can see any difference in the amount of activation in these
regions,'' he added.
And it might provide a good diagnostic test. ``Right now the
only sure way to diagnose Alzheimer's disease is during autopsy.
We would like to have a way to detect it early on.''
Brewer also thinks the MRI technique might help educators
determine the best way to teach things so that students will
remember them.
In another study published this week in the journal Nature,
Dominique de Quervain and colleagues at the University of
California Irvine said they had shown how stress can affect
memory, at least in rats.
They found that the hormone corticosterone, released in
times of acute stress, blocks the retrieval of long-term
memories.
^REUTERS@