Pitch learning

[Annabel Cohen <acohen@xxxxxxx>]

Dear Martin and Stewart and others:

I am willing to concede that sensitivity to overlapping harmonics may
not be the basis of the musical and octave sensitivity of monkeys;
what remains unclear to me is whether there is an "octave circular
pitch processor" or rather than a "small-integer / periodicity-
sensitive processor".

If there is only an "octave circular pitch processing" to account for
octave generalization, one would predict performance in monkeys on 
transpositions to the perfect fifth (ratio 3/2  = 7 semitones up)  to
be as poor as performance on transposition to the tritone (half 
octave = 6 semitones). A study including the perfect fifth 
transposition has not been carried out to the best of my knowledge. 
If performance were superior for the perfect fifth, the "octave 
processor" theory would be incomplete.

How also does one explain the monkey's superior performance on tonal
as opposed to atonal melodies, when tonal melodies are characterized
by tones related by small integer ratios (though typically not
octaves) as compared to tone relations in atonal melodies.

Annabel 

On 24 Feb 2007 at 0:43, Martin Braun wrote:

> Dear Annabel, Stew, and others,
> 
> Annabel Cohen wrote:
> 
> "The evidence in this paper [
> http://web.telia.com/~u57011259/Wright.htm ] for octave
> generalization for tonal melodies by rhesus monkeys is impressive,
> however, whether this reflects something special about sensitivity
> to the octave (chroma) rather than sensitivity to the overtone
> series or periodicity is still not clear from this study."
> 
> Sorry, it IS clear from this study. The authors reported that
> generalization over the distance of two octaves is even stronger
> than that over the distance of one octave. This finding definitely
> rules out the possibility that the monkeys generalized according to
> similarities in the sound spectrum (harmonics). The only remaining
> possibility is that the monkeys, the same as humans, have an octave
> circular pitch processing, which provides the basis for a chroma
> percept.
> 
> Martin
> 
> --------------------------------------------------------------------
> - Martin Braun Neuroscience of Music S-671 95 Klässbol Sweden web
> site: http://w1.570.telia.com/~u57011259/index.htm


------- End of forwarded message -------Annabel J. Cohen, Ph. D.
Department of Psychology
University of Prince Edward Island
Charlottetown, P.E.I. C1A 4P3  CANADA
e:mail acohen@xxxxxxx
phone: (902) 628-4325  office;  (902) 628-4331  lab
fax: (902) 628-4359
www.upei.ca/~musicog
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