Auditory edge detection: A neural model for physiological and psychoacoustical responses to amplitude transients

Primary segmentation of visual scenes is based on spatiotemporal edges that are presumably detected by neurons throughout the visual system. In contra st, the way in which the auditory system decomposes complex auditory scenes is substantially less clear. There is diverse physiological and psychophys ical evidence for the sensitivity of the auditory system to amplitude trans ients, which can be considered as a partial analogue to visual spatiotempor al edges. However, there is currently no theoretical framework in which the se phenomena can be associated or related to the perceptual task of auditor y source segregation. We propose a neural model for an auditory temporal ed ge detector, whose underlying principles are similar to classical visual ed ge detector models. Our main result is that this model reproduces published physiological responses to amplitude transients collected at multiple leve ls of the auditory pathways using a variety of experimental procedures. Mor eover, the model successfully predicts physiological responses to a new set of amplitude transients, collected in cat primary auditory cortex and medi al geniculate body. Additionally, the model reproduces several published ps ychoacoustical responses to amplitude transients as well as the psychoacous tical data for amplitude edge detection reported here for the first time. T hese results support the hypothesis that the response of auditory neurons t o amplitude transients is the correlate of psychoacoustical edge detection.