The reflexive influence of the feedback of reaction time, expectancy wave (CNV) and heart-frequency: Specific and nonspecific effects.

Studied the influence of feedback on the attending processes. Ss were 36 16-31 yr old male candidates for the air service. The effects of the feedback were varying length of the reaction time (RT), the "contingent negative variation" (CNV), and the variation in heart frequency. The CNV, measured by EEG, indicated the reaction during the preparatory interval between the warning signal and the reaction signal or button-pressing. The CNV was characterized by the rapid ascent of the EEG during the preparatory interval and a rapid reduction succeeding the reaction signal. A strong deceleration in heart frequency was associated with a strong CNV amplitude and a short RT. The conditions were no feedback, random feedback, and constant feedback. With random or constant feedback the CNV rose but fell with no feedback. Results indicate no difference between the average CNV amplitude of 2 groups of quick or slow reactors. Different effects of the feedback conditions on the amplitude ! of the CNV were found for the varying lengths of the preparatory interval. Also the length of the preparatory interval influenced the contour of the CNV.