Interoception and Autonomic Correlates during Social Interactions. Implications for Anorexia

Abstract

The aim of this study is to investigate the bodily-self in Restrictive Anorexia, focusing on two basic aspects related to the bodily self: autonomic strategies in social behavior, in which others' social desirability features, and social cues (e.g., gaze) are modulated, and interoception (i.e., the sensitivity to stimuli originating inside the body). Furthermore, since previous studies carried out on healthy individuals found that interoception seems to contribute to the autonomic regulation of social behavior, as measured by Respiratory Sinus Arrhythmia (RSA), we aimed to explore this link in anorexia patients, whose ability to perceive their bodily signal seems to be impaired. To this purpose, we compared a group of anorexia patients (ANg; restrictive type) with a group of Healthy Controls (HCg) for RSA responses during both a resting state and a social proxemics task, for their explicit judgments of comfort in social distances during a behavioral proxemics task, and for their Interoceptive Accuracy (IA). The results showed that ANg displayed significantly lower social disposition and a flattened autonomic reactivity during the proxemics task, irrespective of the presence of others' socially desirable features or social cues. Moreover, unlike HCg, the autonomic arousal of ANg did not guide behavioral judgments of social distances. Finally, IA was strictly related to social disposition in both groups, but with opposite trends in ANg. We conclude that autonomic imbalance and its altered relationship with interoception might have a crucial role in anorexia disturbances.

Keywords: anorexia nervosa; autonomic reactivity; bodily self; interoception; interoceptive accuracy; proxemics; sinus respiratory arrhythmia; social interaction.

Figure 1

Physiological and behavioral proxemics task representations. It show respectively the Fat/Thin Far-gaze conditions (A,B); the Fat/Thin Far-No gaze conditions (C,D); the Fat/Thin Near-gaze conditions (E,F); the Fat/Thin Near-No gaze conditions (G,H).

Figure 2

Marginal means of resting RSA levels for both HCg and ANg. Covariates included in the model were estimated to the following values: age = 22.8, BMI = 18.46, STAI-Trait = 51.63, STAI-State = 42.98, BDI = 17.31. Error bars depict the standard error of the mean; ^***p < 0.001.

Figure 3

Pearson correlations between IA and resting RSA for both HCg (A) and ANg (B).

Figure 4

RSA responses during the Physiological proxemics task of HCg and ANg. Error bars depict the standard error of the mean; g, gaze; ng, no gaze.

Figure 5

Responses during the Behavioral proxemics task of both HCg and ANg in function of the BMI (A) and the Gaze (B). Error bars depict the standard error of the mean. ^***p > 0.001.

Figure 6

Linear regression plots showing the relation between comfort ratings and social disposition (resting RSA) for both HCg (A) and ANg (B).