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-
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.
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
- Martin Braun Neuroscience of Music S-671 95 Klässbol Sweden web
------- End of forwarded message -------Annabel J. Cohen, Ph. D.
Department of Psychology
University of Prince Edward Island
Charlottetown, P.E.I. C1A 4P3 CANADA
phone: (902) 628-4325 office; (902) 628-4331 lab
fax: (902) 628-4359