Offers a look at a study that provides clear evidence in humans of
selective activation of the hippocampal region of the brain in
association with memory function. Contradicts the long-held belief that
language is processed on the left side of the brain; Jogging memories;
PET scans (positron emission tomography); New application of imaging
devices.
By
PT Staff, published on May 01, 1992
news & trends
Struggling to recall a phone number or the name of an old
acquaintance can be an incredibly frustrating feeling. "I don't know. I
just can't think right now," we often sigh.
But University of California psychiatrist Larry Squire begs to
differ with you. At such times, he finds, thinking areas of your brain
are likely to be working harder than when a memory comes with
ease.
For some time now, scientists have suspected that the hippocampus
(a small area near the brain's center) is the command post for creating
and recalling memories of people, places, and things--so called
declarative memory. Now, Squire and a team in San Diego have found that
when you engage in active memory searches, the hippocampus also enlists
the frontal cortex to track down distant recollections.
What makes their work so, well, memorable is that it is the first
to glimpse memory in action in the minds of normal folks. Using PET
(positron emission tomography) scans to take snapshots of brain activity
by measuring blood flow, the team tracked a variety of memory tasks in 18
healthy adults. Earlier work relied on matching brain-activity patterns
with functional problems in brain-damaged persons.
"The results provide clear evidence in humans of selective
activation of the hippocampal region in association with memory
function," the team reports in the Proceedings of the National Academy of
Sciences.
Squire's study is memorable for another important reason: The
pictures contradict the long-held belief that language is processed on
the left side of the brain. When he jogged people's memories by showing
them word fragments and asking them to recall a whole word, the
hippocampal region on the right side lit up more than it did on the left
side. That suggests the subjects used visual images of words to trigger
their memory.
The new application of imaging devices promises to open the
floodgates of human memory research. Picture this occurring sometime in
the near future--perhaps they'll be used to evaluate our educational
efforts.
Tags:
brain,
brain activity,
declarative memory,
frontal cortex,
hippocampus,
language,
left side of the brain,
Memory,
memory function,
national academy of sciences,
PET scan,
proceedings of the national academy,
proceedings of the national academy of sciences,
s center,
visual images
