Disinhibition and the processing of auditory stimulus intensity: An ERP-study.

Twelve Ss (selected from a larger university student sample of 154) were classified as high disinhibitors and 12 as low. All Ss received a series of binaurally presented auditory stimuli varying randomly over 5 intensities (70-210 dB). There were 2 conditions for each S: responding with a fast button press to the tones (signal condition) or listen passively to the tones (non-signal condition). Ss' averaged EEG was subjected to a principal components analysis to identify the major event-related potential (ERP) components. The 2 major factors that could be identified were components around 200 and 300 msec, which were labelled as P2 and P3 respectively. Results of analysis of variance (ANOVA) show that disinhibition is manifest in the ERP components in two different ways.