Marianna Ambrosecchia

Behavioural and Autonomic Correlates During Social Interactions. Implications for Anorexia

Monday, May 9, 2016, 18.30

Venue: Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Luisenstraße 56, Room 144, 10117 Berlin (organized by Katrin Heimann)

Anorexia Nervosa (AN) is characterized by body-size overestimation that reflects a distortion of the body-representation. Interoceptive Sensitivity (i.e. the sensitivity to stimuli originating inside the body), which seems to be impaired in AN, is negatively correlated with self-objectification and seems to contribute to the implicit processes related to bodily representation and to the capacity to adapt to social settings. This capacity, indeed, does not merely reflect high sensitivity in assessing information from the external environment, but also from the inner body.

The present study aimed at investigating the autonomic reactivity during social interactions in a population of patients – Anorexic patients (AN) – whose ability to perceive their bodily signal is impaired. To this purpose, we submitted both Healthy Controls (HC) and AN patients to a well assessed heartbeat perception task. Then, we recorded their RSA (Sinus Respiratory Arrhythmia that reflects a myelinated vagal control of the heart, can be modulated by emotional processing and is positively correlated with social disposition), responses during both resting state and social interaction (Physiological proxemics task). In this task, participants were instructed to view, one by one, two female experimenters (the one obese, the one underweight) slowly approaching them from 470 cm across the room to a tip-to-tip distance (about 30 cm), or vice versa, slowly distancing from them. To better interpret our results, we submitted participants to an “overt” behavioral version of the Physiological proxemics task. In both these tasks, the Body Mass Index (BMI) of experimenters, the presence or the absence of their gaze toward the participant was also manipulated.

Our results demonstrated a flattened autonomic reactivity in AN compared to controls, AN patients seem not to be engaged in social interactions; they did not respond differently to the presence of two different experimenter, and to the manipulation of significant social cues as social distances and the eye contact. These results are not in line with their “overt judgment” of social distances highlighting also the internalization of cultural beliefs related to obese individuals, who are perceived both for AN and HC to be less “attractive” than their thinner counterparts (Harris 1990; Puhl and Heuer 2009; Sobal 2005) in the overt judgment of social distances. The dissociation between autonomic correlates and behavioral responses will be deeply discussed since it could have implication in several field comprising aesthetic emotions.