Subject: Re: pitch neurons From: Israel Nelken <israel(at)MD.HUJI.AC.IL> Date: Wed, 9 Oct 2002 08:16:07 +0100Martin and list, I think that the idea that neurons in the inferior colliculus are sensitive to different periodic modulations of their input is generally accepted. Many neuronal mechanisms would do that - not only intrinsic oscillations. I don't think this is really the issue about which I feel uncomfortable. The point is that these neurons mostly respond to sounds with energy content within their tuning curve (with a lot of fine print attached, I agree), and therefore cannot be interpreted as 'pitch neurons'. When you say 'pitch neuron', I understand that you are looking for a neuron that should respond to pitch irrespective of the underlying physical structure of the stimulus - missing fundamental or not, iterated ripple noise, high-pass filtered click trains, binaural or monaural, and so on and so forth. I don't think that there's any data in the literature (including the very nice Fishman et al. paper that you referred to in a previous message) that even come close. It is precisely this high abstraction level of the pitch, its independence of so many of the physical attributes of the underlying sounds, that to my opinion argues for a high level of processing for the common denominator of all of these sounds. This however does not preclude a partial extraction of some of the features of such sounds earlier (e.g. periodicity at the level of the IC). Eli -- ================================================================== Israel Nelken | Tel: Int-44-1865-272438 Dept. of Physiology, | Fax: Int-44-1865-272469 Hebrew University - | Hadassah Medical School | P.O.Box 12272, Jerusalem 91120 | Email:israel(at)md.huji.ac.il ISRAEL | ==================================================================