Illusions

[Stuart Rosen <stuart@xxxxxxxxxxxxxxxxxxx>]

I was interested to read Richard Warren's recent account of speech
perception being better when the visual information matched the auditory in
terms of perceived distance. This seems plausible to me in that the visual
information could kick in some kind of different processing for sources near
and far away. For example, this is not a million miles away from the work
that Tony Watkins has been doing on normalising for room reverberation
effects in speech perception.

What I find harder to understand is the experiment by Driver (noted by many
in recentl discussions), in which a completely illusory percept led to
improved performance. Maybe I'm wrong about this, but I don't think of
illusions as helping the senses much in this way. For example, in much work
with improving the perception of speech in noise, it is very easy to make
the speech 'sound' better, but very hard to raise its intelligibilty (and
this is a situation in which the signals are being explicitly modified).

Are people aware of other examples like this, in which an illusory percept
improves performance objectively?


--------------------------------------------

Stuart Rosen, Ph.D.
Professor of Speech and Hearing Science
Department of Phonetics & Linguistics
University College London
4 Stephenson Way
London NW1 2HE
England

Tel: (44 171) 380-7404
Fax: (44 171) 383-0752

http://www.phon.ucl.ac.uk/home/stuart/home.htm