'Prepulse inhibition' facilitates a liberal response bias in an auditory discrimination task.
This study examined 'prepulse inhibition' in the context of an auditory two-tone discrimination task performed by 15 healthy subjects. In order to distinguish between masking or excitatory information processes, weak acoustic pulses immediately preceded or succeeded a target or non-target tone in the discrimination. Button-press performance was compared with response in a no-pulse condition. Response bias (beta) became more liberal in the 100 ms prepulse and 200 ms postpulse conditions. Beta correlated with P3b amplitude measures of the event-related potential. The weak pulses increased temporarily the cortical excitability, as measured by the decreased amplitude of the P3b component and thus facilitated a more liberal response bias.
Schall
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University of New South Wales, School of Psychiatry, Prince of Wales Hospital, Randwick, Australia.
Ward
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PB
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001611:Beta Rhythm; D004192:Discrimination, Psychological / Q000502:physiology*; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology