Re: streams and groups

[Bruno Repp <repp@xxxxxxxxxxxxxxxxxxxxxx>]

Al 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@haskins.yale.edu