Fast temporal interactions in human auditory cortex

The temporal resolution of the human primary auditory cortex (AC) was studi ed using middle-latency evoked fields. Paired sounds with either the same o r different spectral characteristics were presented with gaps between the s ounds of 1, 4, 8 and 14 ms. Spatio-temporal modelling showed (I) that the r esponse to the second sound was recognizable with gaps of 1 ms and rapidly increased in amplitude with increasing gap durations, (2) an enhanced N40m amplitude at gaps > 4 ms, (3) delayed N19m-P30m latencies when the stimuli were different. The median psychoacoustical thresholds were 1.6ms for the s ame stimuli and 2.5ms for different stimuli, confirming the electrophysiolo gical evidence for rapid pattern-specific temporal processing in human prim ary auditory cortex. NeuroReport 11:3731-3736 (C) 2000 Lippincott Williams & Wilkins.