How your brain responds to fear and scary moments
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Peer around a corner at a haunted house or watch a horror movie, and you'll know the moment. The one that makes you so scared you jump.
The intrigue: A brain circuit is responsible for determining that reaction and it's adaptable over repeated exposure, according to a new study from a University of Colorado Boulder research team.
Why it matters: The analysis not only shows how people react to scary moments, but could have applications to treat PTSD, anxiety and other mental health conditions.
The big picture: The part of the brain that helps determine threats is a cluster of neurons called the interpeduncular nucleus (IPN). The more terrified, the more active the IPN becomes, says Susanna Molas, an assistant psychology and neuroscience professor, who co-author on the study published in the journal Molecular Psychiatry.
How it works: To test their theories, the researchers tried to spook mice with a shadow of an aerial predator while monitoring the critters' brain activity.
- The initial response was to run. But with repeated exposure over five days, the mice learned the threat was not real and stopped fleeing.
What they're saying: "Our body eventually learns that with repeated exposures to these types of fears that are not aversive that our body has to stop reacting, and that we can adjust to that situation that seems to be more safe," Molas said in a recent interview.
Zoom in: In practice, some people adapt to scary situations more quickly than others, just as some people are more fearful of haunted houses than others.
- This is especially true for people with brain trauma or anxiety. Their IPN may stay active even after repeated exposures.
What's next: Molas says this line of study is relatively new, and the research team is exploring how fear responses are tied to substance use disorders, drug withdrawal and mental health conditions.