RESUMO
The autonomic nervous system (ANS) plays a key role in maintaining physiological homeostasis, and research with neurotypical and autistic individuals has found relations between cardiac autonomic responses, as well as awareness of one's cardiac responses, and social and emotional processing. The current study examined relations between cardiac autonomic activity, heartbeat perception, emotion processing, and levels of autistic traits in a group of college students. Cardiac ANS at baseline and during an emotional picture task was measured, and a heartbeat perception task was used to assess interoceptive accuracy (IA). Questionnaires then assessed autistic traits, alexithymia (difficulties processing one's own emotions), and emotion recognition. Consistent with past work, greatest heart rate deceleration was seen in response to negative images. In the overall sample, no correlations were found between cardiac ANS, IA, autistic traits, and aspects of emotion processing, but when examining individuals high and low on autistic traits separately, distinct associations were found. Within the group of participants with elevated autistic traits, greater baseline respiratory sinus arrhythmia (RSA) was predictive of lower levels of alexithymia and autistic traits, as well as higher IA, but these associations were not seen in participants low on autistic traits. These findings suggest that variability in autistic traits in a non-autistic sample can lead to differential relations between cardiac autonomic responses, awareness of one's cardiac responses, and emotion processing.