Autonomic responses to lateralized cold pressor and facial cooling tasks.

Asymmetry in central nervous system (CNS) control of autonomic nervous system (ANS) activity, a widely debated topic, was investigated via lateralized presentation of two ANS challenges: cold pressor, which elicits primarily sympathetic activation, and facial cooling, a predominantly vagal task. Seventy-three university students (37 female) engaged in these tasks while cardiovascular and electrodermal measures were acquired. Compared to right-side cold pressor, left cold pressor elicited generally larger cardiac, blood pressure, and skin conductance responses, but did not evoke asymmetric changes in heart rate variability. Facial cooling elicited significant increases in vagally mediated heart rate variability, but they were also not lateralized. These findings are consistent with reports of right hemisphere dominance in sympathetic regulation, but indicate that CNS vagal control is relatively symmetric. These results are framed in terms of polyvagal theory and neurovisceral integration two influential models of CNS-ANS integration in the service of adaptive environmental engagement.