Evoked potential correlates of response criterion in auditory signal detection

The amplitude of a late positive component of the average evoked potential recorded from the human scalp varied systematically as a function of the observer's response criterion as defined within the context of signal detection theory. With signal intensity invariant, the P(3), component of the evoked potential increased monotonically with increasing strictness of the criterion. The results are viewed as supporting the signal detection theory approach to the analysis of discrimination behavior as well as providing further evidence of the sensitivity of P(3) to the manipulation of psychological variables.