Preprints on the encoding accuracy of neural populations

[Christian Eurich]

Dear Connectionists,

two preprints on Fisher information and the encoding accuracy of neural
populations are available from my homepage at

http://www-neuro.physik.uni-bremen.de/~eurich/Publications/publications.html

1. Multi-dimensional encoding strategy of spiking neurons
C. W. Eurich and S. D. Wilke
Neural Computation (in press)
Abstract:
Neural responses in sensory systems are typically triggered by a
multitude of stimulus features. Using information theory, we study the
encoding accuracy of a population of stochastically spiking neurons
characterized by different tuning widths for the different features. The
optimal encoding strategy for representing one feature most accurately
consists of (i) narrow tuning in the dimension to be encoded to increase
the single-neuron Fisher information, and (ii) broad tuning in all other
dimensions to increase the number of active neurons. Extremely narrow
tuning without sufficient receptive field overlap will severely worsen
the coding. This implies the existence of an optimal tuning width for
the feature to be encoded. Empirically, only a subset of all stimulus
features will normally be accessible. In this case, relative encoding
errors can be calculated which yield a criterion for the function of a
neural population based on the measured tuning curves.

2. Neural representation of multi-dimensional stimuli
C. W. Eurich, S. D. Wilke and H. Schwegler
Proc. NIPS '99 (in press).
Abstract:
The encoding accuracy of a population of stochastically spiking neurons
is studied for different distributions of their tuning widths. The
situation of identical radially symmetric receptive fields for all
neurons, which is usually considered in the literature, turns out to be
disadvantageous from an information-theoretic point of view. Both a
variability of tuning widths and a fragmentation of the neural
population into specialized subpopulations improve the encoding
accuracy.

Both preprints are available in postscript and g-zipped postscript
format.

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Dr. Christian Eurich
Universitaet Bremen
Institut fuer Theoretische Neurophysik, FB 1
Postfach 330 440
D-28334 Bremen
Germany

Phone:       +49 (421) 218-4559
Fax:         +49 (421) 218-9104
Phone home:  +49 (421) 5577208
Fax home:    +49 (421) 5577050
e-mail:      eurich at physik.uni-bremen.de
homepage:    http://www-neuro.physik.uni-bremen.de/~eurich

 "Die Welt ist alles, was der Fall ist." (L. W.)
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