Do Measures of Autonomic Nervous System Function Correlate With Sensorimotor Performance?

Seamless integration of visual, vestibular, and somatosensory (VVS) systems is key to human movement control. Emerging evidence suggests autonomic nervous system (ANS) function may influence this integration, yet no studies have examined the relationship between ANS activity, indexed by the pupil light reflex, and VVS function. 90 healthy adults (aged 20 - 88 years old) were recruited for this prospective cohort study. ANS function was quantified using pupil light reflex, where response delay, maximum pupil constriction and dilation velocities were recorded. VVS system function was quantified via visual-vestibular testing, including smooth pursuit and voluntary saccades, while somatosensory function was quantified using an Active Movement Extent Discrimination Assessment protocol. Multivariate multiple regression analysis was conducted in RStudio with significance set at p < .05. Follow-up univariate analysis of variance was conducted. VVS performance under differing autonomic profiles - Coactivation, Co-inhibition, Parasympathetic-Dominant and Sympathetic-Dominant - was assessed using one-way analysis of variance. Pupil response delay, maximum pupil constriction and age all significantly predicted combined VVS function (p = .01, p=<.01, p=<.01, respectively), with follow-up univariate analyses demonstrating small-to-moderate effects across individual VVS outcomes (ηp²=0.05 to 0.25). ANS profile of Co-inhibition was significantly correlated with worse VVS performance. This research highlights not just the need to consider ANS function in human movement control but also the ANS profile of the individual at rest. The identification of ANS Co-inhibition as a maladaptive profile in the context of VVS integration challenges existing frameworks that treat VVS and ANS as independent contributors to human movement control.