The impact of warning signal intensity on reaction time and components of the contingent negative variation.
Slow EEG potentials were recorded during performance of a simple reaction task in which warning signal intensity was varied from trial to trial under foreperiod durations of 1, 3 and 8 sec. As shown by speed of reaction, the warning signal had an activating effect which increased with its intensity and decreased with foreperiod duration. This effect was related to the amplitude of a slow potential which appears in the EEG shortly after presentation of the warning signal. This potential is interpreted as a component of the orienting response regulating sensitivity to subsequent stimulation, so that reaction time is affected through change in the effective intensity of the imperative signal.
D000161:Acoustic Stimulation; D001307:Auditory Perception; D003265:Contingent Negative Variation; D004594:Electrophysiology; D006801:Humans; D009949:Orientation; D010775:Photic Stimulation; D011930:Reaction Time; D012018:Reflex; D013016:Sound; D013997:Time Factors