Subject: Re: Physiological models of cochlea activity From: "Francis F. Chen" <ffchen@xxxxxxxx> Date: Wed, 3 Oct 2007 15:26:01 -0700 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Dear John et al.: I've been "listening in" to this series of exchanges with interest. I am not in this field--I am a plasma physicist--and I'm on the list only because I want to understand my own hearing problem. What John suggests amounts to playing God. As physicists, we try to understand how the universe works, but we cannot understand why it is the way it is. The ear is marvelously complex, and understanding it is a challenge. But to design a sensor that an animal needs to survive is an entirely different problem. We may not need to detect acoustic waves at all. Maybe an electromagnetic sensor can do the job, but natural selection or whatever has evolved the cochlea, and we have to live with it. Frank Chen ___________________________ Francis F. Chen, Prof. Emeritus Electrical Engineering Dept. Univ. of California, Los Angeles 56-125B Engr. IV, UCLA Los Angeles, CA 90095-1594 (310) 825-5624, Lab: 206-4841 FAX (310) 206-8495 e-mail: ffchen@xxxxxxxx Web: www.ee.ucla.edu/~ffchen Lab: www.ee.ucla.edu/~ltptl ___________________________ At 12:06 PM 10/3/2007, you wrote: >Dear Matt and all, > >In general, I like your philosophical point of view on modeling. I >think it should be pursued. This paragraph in your response to >Martin has an interesting point: >"Unfortunately ... this proves everything and says nothing ... the >significance of your paper makes us look deeper beyond the cochlea - >which I agree with ... however almost nothing exists in nature without >having reason for existing. (My emphasis) The process of turning >vibration into a >perceived sound takes many interacting steps. For this reason, the >peripheral mechanisms are as significant as the central mechanisms." >What I see in this current discussion is a plethora of studies and >interpretations of the minutiae of cochlear processes before >performance requirements for designing a cochlear model have been >established. As you have indicated elsewhere, these requirements go >far beyond such things as frequency resolution, hair cell response, >or whether there are or are not traveling waves. Such matters are >secondary functions to the primary factors of sensory perception >related to an animal's survival, which, after all, is the reason >why nature invented cochleas. So the main question is: Can anyone do >an analysis based on first principles of survival so as to specify >what a cochlear model should accomplish and how it should be built? >Given such a list of specifications we could then have a credible >computational model. > >This "soft science" approach may seem too idealistic but I can see >no way to devise a mathematical model that can deal with issues of survival. > >John Bates > > >At 10:56 AM 10/2/07, you wrote: > >>>Date: Sat, 29 Sep 2007 16:48:01 +1000 >>>From: Matt Flax <flatmax@xxxxxxxx> >>>Subject: To model or not to model - that is the question ? ... was Re: HC >>> selectivity ... was Re: Physiological models of cochlea activity - >>> alternatives to the travelling wave >>>X-Originating-IP: [132.206.27.49] >>>Sender: AUDITORY - Research in Auditory Perception >>><AUDITORY@xxxxxxxx> >>>To: AUDITORY@xxxxxxxx >>>Reply-to: Matt Flax <flatmax@xxxxxxxx> >>>X-MIME-Autoconverted: from 8bit to quoted-printable by >>>drizzle.cc.mcgill.ca id >>> l8T6m4b6003968 >>>X-IronPort-Anti-Spam-Filtered: true >>>X-IronPort-Anti-Spam-Result: Ao8CADGP/UZ5LEC//2dsb2JhbACBWQ >>>X-IronPort-AV: E=Sophos;i="4.21,212,1188743400"; d="scan'208";a="157167030" >>>X-PMX-Version: 5.3.3.310218, Antispam-Engine: 2.5.2.313940, >>> Antispam-Data: 2007.9.28.232936 >>>Comments: cc: Martin Braun <nombraun@xxxxxxxx> >>>List-Owner: <mailto:AUDITORY-request@xxxxxxxx> >>>List-Subscribe: <mailto:AUDITORY-subscribe-request@xxxxxxxx> >>>List-Unsubscribe: <mailto:AUDITORY-unsubscribe-request@xxxxxxxx> >>>List-Archive: <http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY> >>>List-Help: <http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>, >>> <mailto:LISTSERV@xxxxxxxx?body=INFO AUDITORY> >>>User-Agent: Mutt/1.5.16 (2007-06-11) >>>X-Perlmx-Spam: Probability=7%, RuleHits=__CD 0, __CP_URI_IN_BODY 0, __CT 0, >>> __CTE 0, __CT_TEXT_PLAIN 0, __HAS_MSGID 0, __MIME_TEXT_ONLY 0, >>> __MIME_VERSION 0, __SANE_MSGID 0, __USER_AGENT 0 >>> >>>Martin and others, >>> >>>Too many neurologists and physiologists find a 'new' part of a cell and >>>think they have found gold. >>> >>>The current gold rush is the ribbon synapse. >>> >>>The process of hearing is a complex multi-disciplinary combination of >>>mechanics, electromagnetics, neurology and physiology. Not any one >>>process acts without being affected by the other. >>> >>>Using one of your publications as an example ... if you will allow me to >>>put words in your mouth : >>>We know that the central processes of hearing are statistically >>>significant [1]. For this reason, the central processes are the process >>>of hearing. >>> >>>Unfortunately ... this proves everything and says nothing ... the >>>significance of your paper makes us look deeper beyond the cochlea - >>>which I agree with ... however almost nothing exists in nature without >>>having reason for existing. The process of turning vibration into a >>>perceived sound takes many many interacting steps. For this reason, the >>>peripheral mechanisms are as significant as the central mechanisms. >>> >>>I am a fan of your research into the central processes of hearing ... >>>however am surprised that you do not like models... >>>I personally don't like non-physiological models of hearing. >>>I can see no other way to explain how we hear other then to use >>>multi-disciplinary physiological models ... >>> >>>Matt