Attenuation of visual exploration following stress.

When we explore our surroundings, we frequently move our gaze to collect visual information. Studies have extensively examined gaze behavior in response to different visual scenes. Here, we examined how differences in an individual's state may affect visual exploration, for example, following acute stress. In this study, participants were exposed to either a psychosocial stressor-performing a public speaking task in front of a two-person committee-or a control condition absent stress induction. Elicitation of stress responses was validated using cortisol levels and subjective reports. Stress also led to an extended increase in pupil diameter (a proxy of arousal responses), suggesting it may also affect eye movements. Gaze behavior measures were taken prior and following the stress or control tasks. Acute stress attenuated visual exploration, reflected by fewer saccades and a smaller scanned area. Stress did not have a significant effect on either the tendency to look at social features or at salient regions of the images. These findings diverge from theoretical predictions suggesting that acute stress may facilitate social affiliative behaviors (e.g., Tend-and-Befriend theory). Reduced saccades and a smaller scanned area may be a possible mechanism explaining previous reports showing stress-related effects on various cognitive processes (e.g., visual working memory) that rely on visual exploration.

Empathy Modulates the Effect of Stress Reactivity on Generous Giving.

How does acute stress influence the degree to which we cooperate with others? Research on the effects of stress on social decision-making is guided by two seemingly contrasting theories. Acute stress may trigger a Fight-or-Flight response, manifested by increased anxiety, and more egocentric or selfish behavior. Alternatively, according to the Tend-and-Befriend model, acute stress may induce affiliative behaviors, marked by increased prosociality in an effort to seek and receive social support and protection. Extant studies on the topic do not provide consistent support for either pattern of behavior, with studies showing evidence for both Fight-or-Flight or Tend-and-Befriend like responses. One possibility, may be the nature of social responses to stressful situations differ as a function of the individual. In the current study, we demonstrate an example of such a person-by-situation interaction, showing that acute stress can cause either pro-social or selfish responses, contingent on individual differences in trait empathy. One hundred and twenty three participants (60 F) were assessed for trait empathy using the Interpersonal Reactivity Index; consequently, they underwent either the Trier Social Stress Test-a well-validated paradigm for eliciting acute psychosocial stress-or a non-stress inducing control condition. Following exposure to either the stress or control condition, participants played a one-shot Dictator Game to evaluate their generosity levels. Statistical analyses revealed that acute stress by itself did not affect the amount transferred in the Dictator Game. Rather, individual differences in trait empathy moderated the effects of stress on giving. Elevations in stress-induced cortisol resulted in more generous behavior, but only in individuals high in empathy. In contrast, in individuals low in empathy, a greater rise in stress-induced cortisol resulted in more selfish behavior. Effects were more pronounced in females than males. Our findings highlight the necessity of integrating personality traits as important moderators of the link between stress and sociality.

Social evaluation under stress: Does acute stress affect social attributions and eye gaze?

Acute stress has been found to elicit pro-social, anti-social or null responses in humans. The causes for these contradicting findings are currently poorly understood, and may rise from subjects' characteristics, such as sex or hormonal status, as well as stimuli-based traits, such as group membership. In the current study, 120 subjects performed either the Trier Social Stress Test or a control (non-stress inducing) condition, followed by ranking displayed faces according to several attributes (e.g., trustworthiness, attractiveness, dominance). Participants' eye gaze was also tracked while viewing facial stimuli. We examined how acute stress interacts with participants' sex, female participants' hormonal status (hormonal contraceptives, early-follicular phase and mid-luteal phase), and the observed faces' social group (ethnicity-based in-group or out-groups). In general, frequentist and Bayesian analyses showed that acute stress exposure did not affect social attributions or gaze behavior, nor did it interact with subjects' sex or the group membership of the observed faces. Interestingly, sub-group analyses showed that in females, acute stress interacted with hormonal status to yield heterogenous anti-social effects, such as post-stress reductions in perceived trustworthiness in the early-follicular phase, and lower perceived attractiveness in the mid-luteal phase. Given the small sample sizes for the sub-groups, these results should be viewed as preliminary until further replicated. Our results highlight the necessity for large-scale studies, particularly in females, to further refine existing theories regarding the nature and contexts by which acute stress elicits changes in social cognition and behavior.

A novel perceptual trait: gaze predilection for faces during visual exploration.

Humans are social animals and typically tend to seek social interactions. In our daily life we constantly move our gaze to collect visual information which often includes social information, such as others' emotions and intentions. Recent studies began to explore how individuals vary in their gaze behavior. However, these studies focused on basic features of eye movements (such as the length of movements) and did not examine the observer predilection for specific social features such as faces. We preformed two test-retest experiments examining the amount of time individuals fixate directly on faces embedded in images of naturally occurring scenes. We report on stable and robust individual differences in visual predilection for faces across time and tasks. Individuals' preference to fixate on faces could not be explained by a preference for fixating on low-level salient regions (e.g. color, intensity, orientation) nor by individual differences in the Big-Five personality traits. We conclude that during visual exploration individuals vary in the amount of time they direct their gaze towards faces. This tendency is a trait that not only reflects individuals' preferences but also influences the amount of information gathered by each observer, therefore influencing the basis for later cognitive processing and decisions.