paper available: Size principle and Information theory

[Walter Senn]

The following paper (to appear in Biol. Cybern.) is now available via aftp:

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                  Size Principle and Information Theory
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  by W.Senn, K. Wyler, H.P. Clamann, J. Kleinle, H.-R. Luescher, L. Mueller

                              Abstract:

The several hundreds motor units of a single skeletal muscle may be recruited 
according to different strategies. From all possible recruitment strategies 
nature selected the simplest one: in most actions of a vertebrate skeletal 
muscle the recruitment of its motor units is by increasing size.  
This so-called Size Principle permits a high precision in muscle force 
generation since small muscle forces are produced exclusively by small motor 
units. Larger motor units are only activated if the total muscle force has 
already reached certain critical levels.  
We show that this recruitment by size is not only optimal in precision but also 
optimal in an information theoretical sense.
We consider the motoneuron pool as an encoder generating a parallel binary code
from a common input e.g. from CNS to that pool. The parallel motoneuron code 
is sent further down through the motoneuron axons to the muscle. 
We show that the optimization of this parallel motoneuron code with respect to 
its information content is equivalent to the recruitment of motor units by 
size. Moreover, a maximal information content of the motoneuron code is 
equivalent to a minimal expected error in muscle force generation.

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Retrieval procedure:

     unix> ftp  iamftp.unibe.ch
     Name: anonymous  Password: {your e-mail address}
     ftp>  cd pub/braintool/publications
     ftp>  get InfoTheory.ps.gz
     ftp>  quit
     unix> gunzip InfoTheory.ps.gz
e.g. unix> lpr paper_InfoTheory.ps

Or just to have a look at the www-site

     http://iamwww.unibe.ch:80/~brainwww/publications/