Single and Combined Effects of Sympathetic and Parasympathetic Activity on Perceptual Sensitivity and Attention

Measures of cardiovascular functions are considered highly relevant to the processes involved in sustained attention (e.g., [1.2]). Porges [3] proposed that attentional processing is an ergotropic process, resulting in disruption of normal homeostatic processes and a loss of parasympathetic tone. Resting heart period and an index of vagal activity derived from sinus arrhythmia during a rest period prior to a continuous performance task have been found to be related to attentional performance on the task [2]. It has been hypothesized that high resting cardiac vagal activity is associated with good attentional capacity [2,3]. Munro and colleagues [4], on the other hand, have reported that the greater the degree of task-induced sympathetic nervous system arousal (measured by frequency of spontaneous skin conductance responses), the smaller is the decrease in perceptual sensitivity over time during an attentional task.