Subject: Re: HC selectivity ... was Re: Physiological models of cochlea activity - alternatives to the travelling wave From: Stefan Muenkner <stefan.muenkner@xxxxxxxx> Date: Mon, 1 Oct 2007 16:23:33 +0200 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>A model _is_ a theory. There is no fundamental difference. Models are just theories put work and models, as well as theories, are abstractions of the "real world" and the results are only valid within the definitions of what you want to describe. The quality of a model or a theory lies in its ability to describe the essentials of a system's behaviour in as many aspects as possible with the smallest set of free parameters and equations. In this case I would still say, that the question is whether the experimental data actually represents your system sufficiently well so that you can decide which theory/model describes that system better. I am in no way an expert on cochlear mechanics but my impression is that to date the data is still not sufficient to completely rule out one or the other model/theory. But I might be mistaken here.... Stefan Stefan Muenkner | email: Institute of Physiology/II | stefan.muenkner@xxxxxxxx University of Tuebingen | Gmelinstr. 5 | phone +49 7071 29-88186 D-72076 Tuebingen | fax +49 7071 29--4950 Germany | http://www.physiologie.medizin.uni-tuebingen.de Martin Braun wrote: > Laszlo Toth wrote: > >>> I would like to emphasize this section: >>> "They however are not as important as the ability to understand the >>> underlying dynamics of a complex system. These insights are needed to >>> assess >>> whether the assumptions of a model are correct and complete." >> >> Probably the whole discussion boils down to terminological >> differences. It >> seems to me that you use the term "model" in a more restricted sense. As >> Dick Lyon wrote, "Martin has his own models, but he doesn't want to call >> them that." Your quotation uses the word "understand", and maybe we mean >> slightly different things on that. For an engineer the most natural >> way of >> representing knowledge is by creating mathematical formulae of computer >> simulations - that is, for them understanding practically equals being >> able to create proper models. I don't know what is the meaning of >> "understand" for you. > > I understand the quoted part from the Wikipedia article "Scientific > Modeling" without any mathematical formulae, even though I have not > written it and even though I do not even know who has written it. > > You need meta-knowledge to be able to asses if a model is correct and > useful. In science this meta-knowledge is: All Relevant Data. > > For example, because a wealth of data proves that the basilar membrane > BM) in the mammalian cochlea does not respond to sound levels below > about 60 dB, once the outer hairs cells (OHC) have been made temporally > or ultimately non-functional, I reject all models of cochlear mechanics > that state that the BM triggers the OHCs at ALL sound levels. However > beautiful these models are! > > False models of mammalian cochlear functions have seriously impeded > basic research and medical research for decades - and up to this very > day. For a recent striking misinterpretation of experimental data by the > publishing authors themselves, see this example: > > http://web.telia.com/~u57011259/Russell.htm > > Martin > > --------------------------------------------------------------------- > Martin Braun > Neuroscience of Music > S-671 95 Klässbol > Sweden > web site: http://w1.570.telia.com/~u57011259/index.htm