Physiological and behavioral reactivity to social exclusion: a functional infrared thermal imaging study in patients with psoriasis

Recent studies show that sympathetic nervous system (SNS) activity can be heavily impacted not only by basic threats to survival, but by threats to social bonds. Herein we explored the behavioral and physiological consequences of social exclusion/inclusion in patients with psoriasis, a disease frequently associated with the experience of being ostracized and deficient emotion regulation skills. We employed a virtual ball-tossing game (Cyberball) to induce the experience of social exclusion/inclusion. We then used a Trust game to measure the effects of this social modulation on trust. During Cyberball, Infrared Thermal Imaging was used to record participants' facial temperature and thus obtain an on-line measure of SNS activation. Behavioral data showed that social exclusion shifted participants' trust toward unfamiliar players who had not previously excluded them. Physiological data indicated that, in control participants, social exclusion triggered higher SNS activation than inclusion. No such effect was found in patients with psoriasis, whose SNS activity was the same during inclusion as it was during exclusion, suggesting that they benefit less from inclusive experiences than control participants. In addition, higher SNS activation in patients during social exclusion was linked to higher monetary investment towards unfamiliar players, but not in controls, a result in keeping with the Social Reconnection Hypothesis, according to which emotions triggered by social rejection can be regulated by investing in new social interactions. We also found that an increase in periorbital temperature is accompanied by a decrease in happiness ratings after experiencing social exclusion during the Cyberball game