Re: Increment versus decrement detection

[Al Bregman <al.bregman@xxxxxxxxx>]

Hi Bruno,

The query you sent about your new data was just the sort of thing that
the AUDITORY list should be used for -- the sharing of ideas that can
strengthen research and hasten development.  Thanks from all of us for
sharing these findings.  I hope that the responses will have have
beneficial effects for your research.

Best,

Al

On Wed, Sep 30, 2009 at 10:37 AM, Bruno Repp <repp@xxxxxxxxxxxxxxxx> wrote:
> Dear colleagues:
>
> I recently conducted some experiments in which participants had to detect a
> single changed tone in an isochronous melody consisting of 12 successive
> complex tones (piano tones) of different pitch but equal loudness. The
> change to be detected was either in intensity or in duration, and it was
> either an increment or a decrement. These were four separate tasks, not
> intermixed. The melody containing the change was immediately preceded by the
> same melody not containing any change. I would be grateful for comments or
> references that would help me understand the following trends in my data:
>
> (1) Decrements are harder to detect than increments. Is this well known from
> previous psychoacoustic research? What is the reason?
>
> (2) The pattern of variation in detection scores (hits and false alarms)
> across the 12 tones in the melody, which reflects influences of pitch
> contour and other factors, is uncorrelated between increment and decrement
> detection. It seems like these two tasks have little in common. Why?
>
> (3) In increment detection, both hits and false alarms tend to increase
> across the 12 tones in a melody, but decrement detection shows the opposite
> trend. It is as if tones were expected to become softer as the melody
> progresses. Why?
>
> Many thanks in advance for any helpful replies!
>
> Best,
> Bruno
>
> --
> Bruno H. Repp
> Haskins Laboratories 300 George Street
> New Haven, CT 06511-6624
> Tel. (203) 865-6163, ext. 236
> Fax (203) 865-8963
> http://www.haskins.yale.edu/staff/repp.html
>



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Albert S. Bregman, Emeritus Professor
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