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Re: Cochlea Amplifier models : a new list

Gestur Björn Christianson wrote:

Caution is good, but there is also something like reasonable treatment of data. Both you and Erik have not mentioned the fact that the peak split at 100 dB showed up in two separate experiments in the same animal (Figs. 7A and 7B). Further both of you have disregarded the finding that in both experiments (Fig. 7A and 7B) there are two (Fig. 7A) and three (Figs. 7B) lower rate level points between the two peaks, not one. Thus it is simply not possible to attribute the findings of these authors to stochastic fluctuation.

My point is that in the absence of variability data, it is impossible to say whether any of those points are lower than the others. Your claim of the last sentence requires data the paper does not present.

No paper reports "variability data" of neural recordings. I am afraid that two members of this list do not know what they are talking about. It is just not useful, and usually quite impossible, to record a neuron ten times for each exposure condition and then calculate "variability data". Instead, what is done is that the firing response is averaged over a relatively long recording period. Experienced researches know how long the recording periods have to be, and nobody would even think of multiple repeats and "variability data". The data points in Figs. 7A-D of Geisler et al. (1974) are as clear and as significant as data can be.

Most importantly, none of your or Erik's concerns question the finding that the first fiber neural data do NOT mirror the half- octave shift seen in basilar membrane (BM) behavior.

This is an unrelated point. Based on principles and data that no one has yet questioned (that the auditory nerve fibres are connected to hair cells which in turn are driven by a limited region of the basilar membrane),

The "principle" that the hair cells "are driven by a limited region of the basilar membrane" has been questioned by many researchers for many years.

Rémy Pujol and his colleagues in France state on their outstanding inner ear

"The traveling wave tends now to be considered an epiphenomenon."


where you have to go to "cochlea", then "physics", then last paragraph.

The data of Figs. 7A-D and Fig. 8 of Geisler et al. (1974) are strong evidence in support of this view:


In fact, these data are a further piece of evidence that disproves Bekesy's concept of cochlear function.


----- Original Message ----- From: "Gestur Björn Christianson" <g.christianson@xxxxxxxxx>
To: <AUDITORY@xxxxxxxxxxxxxxx>
Sent: Friday, October 12, 2007 12:42 PM
Subject: Re: Cochlea Amplifier models : a new list