The detection of a temporal gap between two disparate stimuli

When a temporal gap is bounded by a light and a tone, gap detection performance as a function of gap duration is well described by a simple model which characterizes the discrimination as a purely temporal one. When the gap is bounded by two tones, performance is superior and seems to depend on the frequency difference between the tones, but is not well described by the same model. It is suggested that the light-tone performance represents the operation of a central temporal discrimination mechanism, while the tone-tone cases represent the use by Os of nontemporal cues originating in the peripheral auditory system.