Mechanisms of interoceptive-exteroceptive integration during cardio-audio synchrony

Synchronization between bodily signals and external stimuli enables more efficient interactions
with our surroundings. Recently, Pelentritou et al. 2022 found that detection of
omission in a sequence of standard sounds induces a deceleration of the cardiac rhythm
when auditory stimuli were aligned with heartbeats but not when they were not. This interoceptive
effect can be explained within the predictive coding framework with surprise
response and interoceptive active inference or according to the dynamical coupling theory.
To disentangle which one of these three theory is more likely to explain this phenomenon,
we designed an auditory oddball experiment that modulates synchronicity of cardiac and
auditory stimuli, regularity and type of the deviant stimulus. In addition, we run a detection
task experiment to test for cardio-audio synchrony effect on the behavioral scale.
Our preliminary results indicate that cardio-audio synchrony effect is independent of regularity
and type of deviant and has no effect on behavior. Hence, we suggested that the effect
relies on a startled surprise response.