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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
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
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>
Sent: Friday, October 12, 2007 12:42 PM
Subject: Re: Cochlea Amplifier models : a new list