Summary: When feeling stressed people are more likely to jump to more undesirable conclusions based on little evidence, a new study concludes.
When under stress, people reach undesirable conclusions based on weaker evidence than when they are relaxed, finds a new study led by UCL researchers.
The findings, published today in the Journal of Neuroscience, show that stress can make people more likely to conclude the worst scenario is true.
Senior author Professor Tali Sharot (UCL Psychology & Language Sciences and Max Planck UCL Centre for Computational Psychiatry and Ageing Research) said: “Many of the most significant choices you will make, from financial decisions to medical and professional ones, will happen while you feel stressed.
“Often these decisions require you to first gather information and weigh the evidence. For example, you may consult multiple physicians before deciding on a best course of medical treatment. We wanted to find out: does feeling stressed change how you process and use the information you gather?
“Our research suggests that under stress, people weight each piece of evidence that supports undesirable conclusions more than when they are relaxed. In contrast, how they weigh evidence that supports desirable conclusions is not affected by stress. As a result, people are more likely to conclude the worst is true when they are stressed.”
For the study, 91 volunteers played a categorisation game, in which they could gather as much evidence as they wanted to decide whether they were in a desirable environment (which was associated with rewards) or an undesirable environment (which was associated with losses).
They were incentivised for accuracy. Prior to playing the game, 40 of the volunteers were told that they had to give a surprise public speech, which would be judged by a panel of experts. This caused them to feel stressed and anxious.
The researchers found that under stress, the volunteers needed weaker evidence to reach the conclusion that they were in the undesirable environment. By contrast, stress did not change the strength of the evidence needed to reach the conclusion that they were in the desirable environment.
Lead author, PhD student Laura Globig (UCL Psychology & Language Sciences and Max Planck UCL Centre for Computational Psychiatry and Ageing Research) said: “We usually think of stressful situations as a hindrance to our decision-making process. But the pattern of learning we have uncovered may counterintuitively be adaptive, because negative beliefs may drive people to be extra cautious when in threatening environments.”
Funding: The study was funded by Wellcome, and involved researchers at UCL, the University of Tübingen, the Max Planck Institute for Biological Cybernetics, and Yale University.
About this stress research news
Source: UCL Contact: Chris Lane – UCL Image: The image is in the public domain
Critical decisions, such as in domains ranging from medicine to finance, are often made under threatening circumstances that elicit stress and anxiety. The negative effects of such reactions on learning and decision-making have been repeatedly underscored. In contrast, here we show that perceived threat alters the process by which evidence is accumulated in a way that may be adaptive.
Participants (n = 91) completed a sequential evidence sampling task in which they were incentivized to accurately judge whether they were in a desirable state, which was associated with greater rewards than losses, or an undesirable state, which was associated with greater losses than rewards. Before the task participants in the “threat group” experienced a social-threat manipulation. Results show that perceived threat led to a reduction in the strength of evidence required to reach an undesirable judgment.
Computational modeling revealed this was because of an increase in the relative rate by which negative information was accumulated. The effect of the threat manipulation was global, as the alteration to evidence accumulation was observed for information which was not directly related to the cause of the threat.
Requiring weaker evidence to reach undesirable conclusions in threatening environments may be adaptive as it can lead to increased precautionary action.
To make good judgments, people gather information. As information is often unlimited, a decision has to be made as to when the data are sufficiently strong to reach a conclusion.
Here, we show that this decision is significantly influenced by perceived threat. In particular, under threat, the rate of negative information accumulation increased, such that weaker evidence was required to reach an undesirable conclusion.
Such modulation could be adaptive as it can result in enhanced cautious behavior in dangerous environments.