Human auditory-evoked response: Specific effects of signal strength and performance criterion

Computer-averaged auditory-evoked responses were recorded from the scalp of seven human Sa in order to study the effects of both low-signal levels and different performance criteria upon specific components of the waveform. Noise bursts of ?2, 0. +2. or +6 dB seDl8tion level (SL) were presented contingent upon the S’s correct bisection of a temporal interval as the degree of accuracy required from him was systematically varied. Analyses of variance indicated that a positive peak in the waveform at a latency of approximately 300 msec increased in amplitude as the stringency of the performance criterion increased but showed no change as signal strength varied. The negative peak at approximately 125 msec latency increased with increasing signal strength but remained constant as the stringency of the performance criterion was varied.