Signal-detection outcomes on heartbeat and respiratory resistance detection tasks in male and female subjects.

Male and female subjects were compared on heartbeat, respiratory resistance, and light-tone signal-detection tasks. Subjects judged whether a series of 10 tones was coincident with their heartbeats; whether an external load added to the airway was either present or absent during targeted inspiratory cycles; and whether a series of 10 light flashes was matched with auditory tones presented following a fixed delay of either 50 or 100 ms. Nonparametric indices of perceptual sensitivity and response bias indicated that men were more sensitive than women on the resistive load task (p < .05) and on the heartbeat task (p = .07). Performance on the light-tone task was virtually identical. All subjects used a stricter criterion on the respiratory resistance task than on either the heartbeat or the light-tone task; women employed a stricter criterion than men on the heartbeat task. The gender differences may be understood in terms of lateralization of central processing of somesthetic sensory information.