Brain areas involved in seeking information about bad possibilities
Provides
insight into how people decide whether they want to know what future holds
Washington
University School of Medicine
The biology of
our brains may play a role in that. Researchers at Washington University School
of Medicine in St. Louis have identified specific areas and cells in the brain
that become active when an individual is faced with the choice to learn or hide
from information about an unwanted aversive event the individual likely has no
power to prevent.
The findings,
published June 11 in Neuron,
could shed light on the processes underlying psychiatric conditions such as
obsessive-compulsive disorder and anxiety -- not to mention how all of us cope
with the deluge of information that is a feature of modern life.
"People's brains aren't well equipped to deal with the information age," said senior author Ilya Monosov, PhD, an associate professor of neuroscience, of neurosurgery and of biomedical engineering.
"People are constantly checking, checking, checking for news, and some of that checking is totally unhelpful. Our modern lifestyles could be resculpting the circuits in our brain that have evolved over millions of years to help us survive in an uncertain and ever-changing world."
In 2019,
studying monkeys, Monosov laboratory members J. Kael White, PhD, then a
graduate student, and senior scientist Ethan S. Bromberg-Martin, PhD,
identified two brain areas involved in tracking uncertainty about positively
anticipated events, such as rewards. Activity in those areas drove the monkeys'
motivation to find information about good things that may happen.
But it wasn't
clear whether the same circuits were involved in seeking information about
negatively anticipated events, like punishments. After all, most people want to
know whether, for example, a bet on a horse race is likely to pay off big. Not
so for bad news.
"In the
clinic, when you give some patients the opportunity to get a genetic test to
find out if they have, for example, Huntington's disease, some people will go
ahead and get the test as soon as they can, while other people will refuse to
be tested until symptoms occur," Monosov said. "Clinicians see
information-seeking behavior in some people and dread behavior in others."
To find the neural circuits involved in deciding whether to seek information about unwelcome possibilities, first author Ahmad Jezzini, PhD, and Monosov taught two monkeys to recognize when something unpleasant might be headed their way. They trained the monkeys to recognize symbols that indicated they might be about to get an irritating puff of air to the face.
For example, the monkeys
first were shown one symbol that told them a puff might be coming but with
varying degrees of certainty. A few seconds after the first symbol was shown, a
second symbol was shown that resolved the animals' uncertainty. It told the
monkeys that the puff was definitely coming, or it wasn't.
The researchers
measured whether the animals wanted to know what was going to happen by whether
they watched for the second signal or averted their eyes or, in separate
experiments, letting the monkeys choose among different symbols and their
outcomes.
Much like
people, the two monkeys had different attitudes toward bad news: One wanted to
know; the other preferred not to. The difference in their attitudes toward bad
news was striking because they were of like mind when it came to good news.
When they were given the option of finding out whether they were about to
receive something they liked -- a drop of juice -- they both consistently chose
to find out.
"We found
that attitudes toward seeking information about negative events can go both
ways, even between animals that have the same attitude about positive rewarding
events," said Jezzini, who is an instructor in neuroscience. "To us,
that was a sign that the two attitudes may be guided by different neural
processes."
By precisely measuring neural activity in the brain while the monkeys were faced with these choices, the researchers identified one brain area, the anterior cingulate cortex, that encodes information about attitudes toward good and bad possibilities separately.
They found a second brain area, the ventrolateral
prefrontal cortex, that contains individual cells whose activity reflects the
monkeys' overall attitudes: yes for info on either good or bad possibilities
vs. yes for intel on good possibilities only.
Understanding
the neural circuits underlying uncertainty is a step toward better therapies
for people with conditions such as anxiety and obsessive-compulsive disorder,
which involve an inability to tolerate uncertainty.
"We started
this study because we wanted to know how the brain encodes our desire to know
what our future has in store for us," Monosov said. "We're living in
a world our brains didn't evolve for. The constant availability of information
is a new challenge for us to deal with. I think understanding the mechanisms of
information seeking is quite important for society and for mental health at a
population level."
