Heartfelt gaze: Cardiac afferent signals and vagal tone affect gaze perception

Perceiving others' gaze direction is an essential aspect of social interactions. The cone of direct gaze (CoDG) refers to the range within which an observer perceives a gaze as looking directly at them. Previous research has demonstrated that self-relevant exteroceptive cues can widen the CoDG. However, the effect of self-relevant interoceptive information on the CoDG remains unknown. This study investigated the contribution of cardiac afferent signals and vagal tone to the perception of gaze from others. We used a modified gaze discrimination task to synchronize face stimuli with various gaze directions to specific phases of the cardiac cycle. Results revealed that participants with higher heart rate variability (HRV) exhibited a wider CoDG during cardiac systole (when cardiac signals are maximally represented in the brain). However, no effect was observed during cardiac diastole (when cardiac signals are quiescent). Moreover, this effect was independent of individual differences in anxiety levels and autistic traits. These findings are evidence that individuals with greater cardiac vagal control are more sensitive to cardiac afferent signals during systole, which leads to a stronger self-directed perception of others' gaze under transient and ambiguous gaze perception conditions. Our findings highlight the self-referential role of cardiac interoceptive signals in gaze perception and expand our knowledge of interoceptive influences on social judgment.