Wearing your heart on your screen: Investigating congruency-effects in autonomic responses and their role in...

The experience of one's embodied sense of self is dependent on the integration of signals originating both from within and outwith one's body. During the processing and integration of these signals, the bodily self must maintain a fine balance between stability and malleability. Here we investigate the potential role of autonomic responses in interoceptive processing and their contribution to the stability of the bodily self. Using a biofeedback paradigm, we manipulated the congruency of cardiac signals across two hierarchical levels: (i) the low-level congruency between a visual feedback and participant's own cardiac signal and (ii) the high-level congruency between the participants' beliefs about the identity of the cardiac feedback and its true identity. We measured the effects of these manipulations on high-frequency heart rate variability (HF-HRV), a selective index of phasic vagal cardiac control. In Experiment 1, HF-HRV was sensitive to low-level congruency, independently of whether participants attempted to regulate or simply attend to the biofeedback. Experiment 2 revealed a higher-level congruency effect, as participants' prior veridical beliefs increased HF-HRV while when false they decreased HF-HRV. Our results demonstrate that autonomic changes in HF-HRV are sensitive to congruencies across multiple hierarchical levels. Our findings have important theoretical implications for predictive coding models of the self as they pave the way for a more direct way to track the subtle changes in the co-processing of the internal and external milieus.