An electrophysiological correlate of phonemic discrimination

Event-related potentials have not, to date, been used to probe speech discrimination processes. The purpose of the present study was to determine whether correct speech discrimination performance was associated with characteristic changes in contingent negative variation (CNV) waveform. 9 paid subjects were placed in a 'go/no-go' discrimination paradigm. Correct perception of phoneme differences (no-go) was associated with an abrupt decrease in 'orienting wave' (O-wave) amplitude. The moment of 'O-wave' resolution generally occurred during presentation of key acoustic features differentiating the 'go' from the 'no-go' stimuli.