Stress diminishes our capacity to sense new dangers, psychology research finds

October 2, 2017, New York University
Credit: George Hodan/public domain

Being under stress diminishes our abilities to predict new dangers that we face, a team of psychology researchers finds. Its work runs counter to the conventional view that stress enhances our ability to detect and adjust to these changing sources of threat.

"Stress does not always increase perceptions of danger in the environment, as is often assumed," explains Candace Raio, a postdoctoral researcher at New York University and the study's lead author. "In fact, our study shows that when we are under stress, we pay less attention to changes in the environment, potentially putting us at increased risk for ignoring new sources of threat. As a result, stress can reduce the flexibility of our responses to threats by impairing how well we track and update predictions of potentially dangerous circumstances."

The research, conducted in collaboration with Jian Li, a scientist at Peking University, appears in the latest issue of the journal Proceedings of the National Academy of Sciences.

Although learning to predict threats in our environment is critical to survival, note the study's authors, who also include NYU Professor Elizabeth Phelps and Assistant Professor Catherine Hartley, it is equally important to be flexible in order to control these responses when new sources of threat change—for instance, from an oncoming car to an out-of-control skateboarder.

To test our ability to learn to flexibly update threat responses under stressful conditions the researchers conducted a series of experiments that centered on "Pavlovian threat-conditioning." Here, the subjects viewed images on a computer screen. The appearance of some images were coupled with a mild, electric wrist-shock, serving as a "threat cue," while other images were never paired with a shock ("safe cue").

A day later, half of the participants underwent a laboratory procedure designed to induce stress—this "stress group" placed their arm in an ice-water bath for a few minutes, which elevated two known (alpha-amylase and cortisol). Later, all of the study's subjects repeated the threat-conditioning procedure. However, this time the cue outcomes switched: the earlier threatening cue no longer predicted shock, but the formerly safe cue did.

While the subjects viewed the images, the scientists collected physiological arousal responses in order to measure how individuals anticipated the outcome of each cue.

On the second day of the experiment, the stress group was less likely to change their responses to threats (the formerly safe visuals that were now paired with shocks) than was the control group, an indication that stress impaired its ability to be flexible in detecting new threats. Specifically, stressed participants showed reduced physiological to the new cue, suggesting that they did not fully switch their association with this cue from safe to threatening.

The researchers then applied a computational learning model to further understand how stress affects flexibility in decision making. This analysis revealed a learning deficit for the subjects put under the stress condition—specifically, affected an attentional signal ("associability")—that participants used to update the cue associations. In short, this resulted in a slower rate of learning.

Explore further: Stress heightens fear of threats from the past

More information: Candace M. Raio el al., "Stress attenuates the flexible updating of aversive value," PNAS (2017). www.pnas.org/cgi/doi/10.1073/pnas.1702565114

Related Stories

Stress heightens fear of threats from the past

August 7, 2017
Recognizing threats is an essential function of the human mind—think "fight or flight"—one that is aided by past negative experiences. But when older memories are coupled with stress, individuals are likely to perceive ...

Childhood maltreatment may change brain's response to threat

September 11, 2017
Neural activity associated with defensive responses in humans shifts between two brain regions depending on the proximity of a threat, suggests neuroimaging data from two independent samples of adults in the Netherlands published ...

Study: Mild stress can make it difficult to control your emotions

December 12, 2013
Even mild stress can thwart therapeutic measures to control emotions, a team of NYU neuroscientists has found.

Even mild stress can make it difficult to control your emotions, study finds

August 26, 2013
Even mild stress can thwart therapeutic measures to control emotions, a team of neuroscientists at New York University has found. Their findings, which appear in the journal Proceedings of the National Academy of Sciences, ...

Scientists pinpoint a neural center of resilience

July 19, 2016
Why some people handle stress better than others is a question that has fascinated scientists for decades. Now a Yale-led team reports that flexible brain activity in a particular area of the brain may predict resilience. ...

Brain activity may be predictor of stress-related cardiovascular risk

August 23, 2017
The brain may have a distinctive activity pattern during stressful events that predicts bodily reactions, such as rises in blood pressure that increase risk for cardiovascular disease, according to new proof-of-concept research ...

Recommended for you

Self-perception and reality seem to line-up when it comes to judging our own personality

December 14, 2018
When it comes to self-assessment, new U of T research suggests that maybe we do have a pretty good handle on our own personalities after all.

Levels of gene-expression-regulating enzyme altered in brains of people with schizophrenia

December 14, 2018
A study using a PET scan tracer developed at the Martinos Center for Biomedical Imaging at Massachusetts General Hospital (MGH) has identified, for the first time, epigenetic differences between the brains of individuals ...

Researchers discover abundant source for neuronal cells

December 13, 2018
USC researchers seeking a way to study genetic activity associated with psychiatric disorders have discovered an abundant source of human cells—the nose.

Video game players frequently exposed to graphic content may see world differently

December 13, 2018
People who frequently play violent video games are more immune to disturbing images than non-players, a UNSW-led study into the phenomenon of emotion-induced blindness has shown.

New genetic clues to early-onset form of dementia

December 13, 2018
Unlike the more common Alzheimer's disease, frontotemporal dementia tends to afflict young people. It accounts for an estimated 20 percent of all cases of early-onset dementia. Patients with the illness typically begin to ...

How teens deal with stress may affect their blood pressure, immune system

December 13, 2018
Most teens get stressed out by their families from time to time, but whether they bottle those emotions up or put a positive spin on things may affect certain processes in the body, including blood pressure and how immune ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.