Subject: Re: / Jont, Al, Peter From: Pierre Divenyi <marva4!EarLab!pierre(at)UCDAVIS.EDU> Date: Tue, 3 Jun 1997 14:28:02 GMT
In my last note, I responded to Jont and raised issues similar to what Al does in his last note (and Kevin raised first with his scratchy record analogy): The auditory system does not seem to be doing a great job integrating temporal information across different frequency channels. The following papers address the problem from the standpoint of the psychophysics of envelope processing (in the range of 1 to 100-or-so milli- seconds, depending on how you define the intervals). Divenyi, P. L., & Danner, W. F. (1977). Discrimination of time intervals marked by brief acoustic pulses of various intensities and spectra. Perception and Psychophysics, 21, 125-142. Divenyi, P. L., & Sachs, R. M. (1978). Discrimination of time intervals bounded by tone bursts. Perception and Psychophysics, 24, 429- 436. Formby, C., Sherlock, L.P., & Forrest, T.G. (1996). An asymmetric roex filter model for describing detection of silent temporal gaps in sinusoidal markers. Auditory Neuroscience, 3(1), 1-20. I also suggested about a week ago that it is possible to estimate the delay between the periphery and the structure (quite probably cortical) at which the time intervals are computed, by looking at the distributions in a detection/discrimination task. The underlying models are quite simple and pretty much taken for granted by the psychoacoustics community. What results in the above papers suggest is that there must be an extra stage of processing between the one running the internal timer **within** a single channel/stream and the one timing events when the markers are in different channels/streams. Does anybody know if this or similar problems have been looked at by stochastic modellers? By physiologists? Peter (Cariani)? Pierre PS: Chuck, Lloyd's coincidence detector is also frequency-specific.