[Cortical reactivity during reaction time tests in sprinters].

Thirty-two male subjects divided into 4 groups (of 8--controls, witnesses, students in physical and athletic education (PAE) and sprinters--were submitted to 1) simple auditory stimuli, 2) paired auditory stimuli, and 3) simple and paired auditory stimuli. The subjects, except the control group, have been assigned the task of quickly responding by pressing a button, accordingly the detection of the simple stimulus, of the imperative stimulus when the stimuli are paired, or the simple and imperative stimuli when they are randomly matched. The results show that the amplitude of the event-related potential components and of the CNV is significantly more important in sprinters and PEA students than in other groups. The differences indicate a greater adaptative reactivity of attentional mechanisms in athletes. In all the groups, the variations in the event-related potentials and of the CNV, as well as the variations of RT between conditions 1 and 2, indicate that the effects of activation and preparation differ depending on whether or not the signal for execution of the motor response is preceded by a preparatory signal. The decrease in event-related potentials and CNV amplitude and the elongation of RT in divided attention condition suggest that when subjects have to distinguish, at the same time, simple and paired auditory stimuli, interferences are induced. The attention is disturbed performance are impaired. Sprinters are less susceptible to interferences than control persons, their performances remaining significantly better.