Subject: pitch neurons From: Martin Braun <nombraun(at)POST.NETLINK.SE> Date: Tue, 1 Oct 2002 15:13:29 +0200Two years ago, on October 21-2000, I had replied to a question from Suresh Krishna as follows: QUOTE "martin braun wrote: ...the extracted f0-pitch is coded at its frequency place by discharge rate... is there a peer-reviewed reference for this statement?" Very good question. A peer-reviewed report on this issue may still be pending. But there is a conference report from 1996, which appeared as a book chapter in 1997: Biebel, U.W., Langner, G., 1997. Evidence for "pitch neurons" in the auditory midbrain of chinchillas. In: Syka, J. (Ed.), Acoustic Signal Processing in the Central Auditory System. Plenum Press, New York, pp. 263-269. UNQUOTE We can now add that the "peer-reviewed reference for this statement" is no longer pending. It appeared in July this year: Ulrich W. Biebel and Gerald Langner (2002). Evidence for interactions across frequency channels in the inferior colliculus of awake chinchilla. Hear Res 169, 151-168. The authors have confirmed and largely extended the evidence from the 1996 conference report. However, they do not use the term "pitch neuron" in this paper. Perhaps they plan to do this in a new study with stimuli consisting of harmonic complex tones. They already announced preliminary data of such experiments in the present paper (p. 164): "Preliminary data carried out with harmonic complexes lacking f0 showed that neurons in the ICC indeed respond to spectrally broad periodic signals as well as to HC-SAM (data not shown). Responses were restricted to complexes having the period of the neuron's BF and lying spectrally in a certain 'integration range' of the neuron." [HC-SAM: amplitude modulated signal with high carrier, far above the neuron's BF] Martin ------------------------------------------- Martin Braun Neuroscience of Music S-671 95 Klässbol Sweden e-mail: nombraun(at)post.netlink.se web site: http://hem.netlink.se/~sbe29751/home.htm