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Re: Pitch neurons (was "Autocorrelation-like ...")



Nikolay G. Bibikov asked:

> My question is very simple.
> Who really observed a central auditory units with internal periodicity?
.......
> To see a real unit with internal periodicity I would like to observe a
> periodicity in spontaneous activity or in hasard fubction of evoked
> activity or at last in latency distibution.

The first two facts have been observed 10 years ago, the third fact 16 years
ago. In Braun (1999) you can read the following two paragraphs:

"The most comprehensive evidence for tuned neural resonance, to date, was
found by Schwarz et al. (1993) in the auditory midbrain of a bird, the
chicken. After surgical removal of both cochleae 37 oscillating cells were
recorded. Three response modes revealed identical neuron-specific preferred
frequencies from 60 to 840 Hz:
(1) spontaneous firing, (2) firing upon a 0.1 ms electrical impulse applied
at the cochlear nerve, and (3) firing upon a random sequence (Poisson, mode
2-3 ms) of 0.1 ms electrical pulses, also applied at the cochlear nerve."

"Langner et al. (1987) further showed that onset latency systematically
decreased with increasing BMF [best modulation frequency]. They suggested
that characteristic resonant periods would explain both the BMF effect and
the latency effect."


> The only hints  about sach effects I could see in some G.Langner studies,
> which have done mainly on guinea foul.

Most of Langner's data are from the cat.

Schwarz, D.W.F., Dezs÷, A., Neufeld, P.R., 1993. Frequency selectivity of
central auditory neurons without inner ear. Acta Otolaryngol. (Stockh.) 113,
266-270.

Langner, G., Schreiner, C.E., Merzenich, M.M., 1987. Covariation of latency
and temporal resolution in the inferior colliculus of the cat. Hear. Res.
31, 197-201.

Braun, M., 1999. Auditory midbrain laminar structure appears adapted to f0
extraction: further evidence and implications of the double critical
bandwidth. Hear. Res. 129, 71-82.

Martin

-------------------------------------------
Martin Braun
Neuroscience of Music
S-671 95 Klassbol
Sweden
e-mail: nombraun@telia.com
web site: http://w1.570.telia.com/~u57011259/index.htm