There is More to a Heartbeat: The Role of Autonomic Regulation in the Psychophysiological Stability of the Self in Relation to the External Physical and Social World

The experience of one’s own body is dependent on the integration of signals originating both from the body’s internal milieu and the outside world. During the processing and integration of these signals, the bodily self must maintain a fine balance between stability and malleability. Across 4 studies, this thesis explored the role of autonomic regulation in maintaining psycho-physiological stability. Specifically, the present studies addressed different aspects of the individuals’ engagement in explicit inference and unconscious interoceptive inference about one’s self in relation to the external world and others. The main theory of this thesis predicted that autonomic regulation could contribute to the psychophysiological stability of the self across multiple hierarchical levels. In all studies participants received either congruent or incongruent feedback of their cardiac activity, while the experimental conditions were optimised to the rationale of the corresponding study. According to the findings of Study 1 and 2, autonomic regulation does contribute to the integration of self-relevant information across different hierarchical levels resulting in physiological stability. Study 3 revealed that autonomic regulation and physiological synchrony could function as self-stability preserving processes during competition. Finally, going beyond non-conscious interoceptive inference, Study 4 used a novel cardiac recognition paradigm that employed a set of different measures that correspond to different facets of interoception (i.e. the ability to infer the state of one’s body). Integrating behavioural, psycho-physiological and metacognitive measures, the findings of Study 4 suggest that people can use different strategies (potentially linked to different hierarchical levels in the brain) to reach valid inferences about their sensations. When taken together, the findings of the present thesis have important theoretical implications for predictive coding models of the self and social-affective neuroscience as they pave the way for a more direct application of abstract theories in experimental designs. The general discussion outlines a novel mechanistic framework of interpersonal congruency that could contribute to closing the arbitrary gap between individual and social approaches in experimental designs.