Subject: Re: streams and groups From: Bruno Repp <repp(at)ALVIN.HASKINS.YALE.EDU> Date: Mon, 14 May 2001 10:44:08 -0700Al Bregman's excellent explanations answer most questions one might have about streams, units, and groups. Just one small comment with regard to these statements: >Units--being psychological--are the outputs, not the inputs, of >the auditory system. The temporal variation of acoustic energy is the input. >Like the streams in which they reside, "groups", as defined >above, are psychological entities, not physical ones. I agree that the perception of units and groups is a psychological process. However, what should the segmentations in the input be called that give rise to the perception of units and groups? Al focused on discontinuities in the input, but they are BETWEEN the things that are to be named. My view is that there are in fact units, groups, and streams in the input signal. These are PHYSICAL (OBJECTIVE) units, groups, and streams. Whether their perception results in PSYCHOLOGICAL (SUBJECTIVE) units, groups, or streams is the empirical question that Al has done so much excellent work on. The physical units, groups, or streams might also be called POTENTIAL psychological units, groups, or streams. But I do believe we need names for structures in physical signals, and those names probably should be the same as the names for the psychological structures, with the added qualifier "physical" or "objective" or "potential". --Bruno Bruno H. Repp Research Scientist Haskins Laboratories 270 Crown Street New Haven, CT 06511-6695 Tel. (203) 865-6163, ext. 236 FAX (203) 865-8963 e-mail: repp(at)haskins.yale.edu