|
A University of Alberta medical researcher, in
collaboration with colleagues at Duke University, identified
brain activity that causes older adults to remember fewer
negative events than their younger counterparts.
"Seniors actually use their brain differently
than younger people when it comes to storing memory, especially
if that memory is a negative one," said study author Dr. Florin
Dolcos, an assistant professor of psychiatry and neuroscience in
the Faculty of Medicine & Dentistry.
The study, published online in December in the
U.S.-based journal Psychological Science, found
age-related changes in brain activity when participants with an
average age of 70 where shown standardized images that depicted
either neutral or strongly negative events.
The research team asked older and younger
participants to rate the emotional content of these pictures
along a pleasantness scale, while their brain activity was
monitored with a functional magnetic resonance imaging (fMRI)
machine, a high-tech device that uses a large magnet to take
pictures inside the brain. Thirty minutes later, participants
were unexpectedly asked to recall these images. The older
participants remembered fewer negative images than the younger
participants.
Brain scans showed that although both groups
had similar activity levels in the emotional centres of the
brain, they differed when it came to how these centres
interacted with the rest of the brain.
The older participants had reduced
interactions between the amygdala, a brain region that detects
emotions, and the hippocampus, a brain region involved in
learning and memory, when shown negative images. Scans also
showed that older participants had increased interactions
between the amygdala and the dorsolateral frontal cortex, a
brain region involved in higher thinking processes, like
controlling emotions. The older participants were using thinking
rather than feeling processes to store these emotional memories.
Dr. Dolcos conducted the study in
collaboration with senior researcher Dr. Roberto Cabeza and
graduate student Ms. Peggy St. Jacques, both of Duke University.
In another article published earlier this year
in the journal Neurobiology of Aging, the team reported that
healthy seniors are able to regulate emotion better than younger
people, so they are less affected by upsetting events. They also
conducted further research to look at the relationship between
emotion, memory and aging.
"Seniors' brains actually work differently
than younger individuals - they have somehow trained their brain
so that they're less affected both during and after an upsetting
event," said Dolcos, a member of the Alberta Cognitive
Neuroscience Group, a University of Alberta research team that
explores how the brain works in human thought, including issues
like perception, memory and emotion.
This research may improve understanding of
mental health issues like depression and anxiety, where patients
have trouble coping with emotionally challenging situations, and
suffer from intrusive recollection of upsetting memories. These
findings may also help to enhance memory in older adults with
memory deficits, and assist with research related to dementia,
including Alzheimer's disease, in which patients have difficulty
with remembering personal events |
