Subject: Re: NIDCD plan From: Al Bregman <bregman(at)HEBB.PSYCH.MCGILL.CA> Date: Fri, 29 Dec 1995 22:19:52 -0500Dear Neal, In reply to your question to the list, I can only comment on the work from my lab. I think it is becoming clearer that while the type of organization that the Gestalt psychologists described, mainly in vision, can be observed in auditory perception too, it can also be observed that top-down processes, which were neglected by the Gestaltists, play an essential role in the organization of the auditory signal. The clearest example is in speech perception, where familiarity with speech allows a listener to penetrate the camouflage (bottom-up grouping) that is obscuring a message. I think it will be important in the next few years to try to discover the properties of top-down processes and how they interact with the Gestalt-like bottom-up processes. Another important development that I anticipate in the next few years is the description and classification of consistent individual differences in the use of various cues for perceptual organization. Informal observations in the laboratory indicate that some subjects are more influenced by one cue and than another, and the relative susceptibility may vary from subject to subject. We need to know whether the differences are systematic. Can a profile be formed for a subject showing the relative importance, for him or her, of various cues in solving the scene analysis problem? Our ability to describe hearing-impaired individuals in this way may be of value in deciding on the best form of auditory prosthesis for them. A third trend that I observe is the accelerating development of computational models of auditory scene analysis. There have been three important meetings of computer scientists and engineers on this topic in the past 15 months. My hope is that the modellers will attempt to bring a wider set of organizational phenomena into their models. My forthcoming CD of phenomena of auditory organization may help to sensitize modellers to the range of phenomena that need to be explained, and to set criteria which such models should meet. Best wishes, Al --------------------------------------------------------------------- Albert S. Bregman, Professor, Dept of Psychology, McGill University 1205 Docteur Penfield Avenue, Montreal, Quebec, Canada H3A 1B1. Phone: +1 514-398-6103 Fax: -4896 Email: bregman(at)hebb.psych.mcgill.ca ---------------------------------------------------------------------