The effect of acute social stress on the recognition of facial expression of emotions

Abstract

This study investigates the effect of acute social stress on the recognition of facial expression of emotions in healthy young men. Participants underwent both a standardized psychosocial laboratory stressor (TSST-G) and a control condition. Then, they performed a homemade version of the facial expressions megamix. All six basic emotions were included in the task. First, our results show a systematic increase in the intensity threshold for disgust following stress, meaning that the participants' performance with this emotion was impaired. We suggest that this may reflect an adaptive coping mechanism where participants attempt to decrease their anxiety and protect themselves from a socio-evaluative threat. Second, our results show a systematic decrease in the intensity threshold for surprise, therefore positively affecting the participants' performance with that emotion. We suggest that the enhanced perception of surprise following the induction of social stress may be interpreted as an evolutionary adaptation, wherein being in a stressful environment increases the benefits of monitoring signals indicating the presence of a novel or threatening event. An alternative explanation may derive from the opposite nature of the facial expressions of disgust and surprise; the decreased recognition of disgust could therefore have fostered the propensity to perceive surprise.

Figure 1

Examples of continua of morphed emotions used in the experimental task of Facial megamix expressions. The first continuum represents a combination of fear and disgust (identity 1) and the second continuum represents a combination of anger and sadness (identity 2).

Figure 2

Comparison of participants’ salivary cortisol levels between experimental conditions.

Figure 3

Comparison of participants’ subjective stress levels between experimental conditions.

Figure 4

Intensity threshold between experimental conditions for (a) the expression of disgust and (b) the expression of surprise.

Figure 5

Proportion of time anger was answered when disgust was the dominant expression presented; for each combination of emotions including disgust and between experimental conditions.

Figure 6

Proportion of time happiness was answered when disgust was the dominant expression presented; for each combination of emotions including disgust and between experimental conditions.

Figure 7

Proportion of time surprise was answered when it was the dominant expression presented; for each combination of emotions including surprise and between experimental conditions.