Sex differences in performance and associated cardiac activity during a reaction time task

Measures of reaction time and cardiac activity were recorded from 10 males and 10 female subjects during a variable foreperiod reaction time task. Males showed faster reaction times, greater cardiac decelerations, and higher levels of heart-rate variability during the foreperiod. Trend analyses revealed sex differences in the heart-rate response to the onset of the warning signal, but not in the response to the imperative signal. These results indicate that those measures of cardiac activity which have been shown previously to predict performance tend to differentiate between the sexes when there are sex differences in performance.