No subject

[Christiane Linster]

The followowing two papers are now available by ftp:

TOWARDS A COGNITIVE UNDERSTANDING OF ODOR DISCRIMINATION:
COMBINING EXPERIMENTAL AND THEORETICAL APPROACHES

Claudine Masson (1) and Christiane Linster (2)

(1) Laboratoire de Neurobiologie ComparEe des InvertEes
 INRA-CNRS (URA 1190)
BP 23, 91440 Bures-sur-Yvette, France
tel, fax: 69 07 20 59
 e-mail: masson at jouy.inra.fr

(2) Laboratoire d'Electronique, ESPCI, 10 rue Vauquelin,
75005 Paris
tel: 40 79 44 61
e-mail: linster at neurons.fr

Key words: feature extraction; modeling; odor discrimination; olfactory pro
cessing.

Abstract

In response to changes in odorous environmental conditions, most species
(ranging from lower invertebrates to mammals), demonstrate high adaptive
behavioral performances.  Complex natural chemical signals (i.e. odorous
blends involved in food search), are particularly unstable and fluctuating,
in quality, space and time. Nevertheless, adapted behavioral responses
related to meaningful odor signals can be observed even in complex natural
odorous environments, demonstrating that the underlying olfactory neural
network is a very dynamic pattern recognition device.  In the honeybee, a
large amount of experimental data have been collected at different levels
of observation within the olfactory system, from signal processing to
behavior, including cellular and molecular properties. However, no set of
data considered by itself can give insight into the mechanisms underlying
odor discrimination and pattern recognition.  Here, by concentrating on
deciphering the neural mechanisms underlying encoding and decoding of the
olfactory signal in the two first layers of the neural network, we
illustrate how a theoretical approach helps us to integrate the different
experimental data and to extract relevant parameters (features) which might
be selected and used to store an odor representation in a behavioral
context.

To appear in Behavioral Processes, Special Edition on Cognition and
Evolution


A NEURAL MODEL OF OLFCATORY SENSORY MEMORY IN THE
HONEYBEE ANTENNAL LOBE

Christiane Linster
Laboratoire d'Electronique, ESPCI
10, Rue Vauquelin, 75005 Paris
linster at neurones.espci.fr

Claudine Masson
Neurobiologie ComparEe des Inverteb
INRA, CNRS (URA 1190)
911140 Bures sur Yvette, France
masson at jouy.inra.fr

Abstract

We present a neural model for olfactory sensory memory in the honey bee's
antennal lobe. In order to investigate the neural mechanisms underlying
odor discrimination and memorization, we exploit a variety of
morphological, physiological and behavioral data. The model allows us to
study the computational capacities of the known neural circuitry, and to
interpret under a new light experimental data on the cellular as well as on
the neuronal assembly level.  We propose a scheme for memorization of the
neural activity pattern after stimulus offset by changing the local balance
between excitation and inhibition. This modulation is achieved by changing
the intrinsic parameters of local inhibitory neurons or synapses.


To appear in Neural Computation , Volume 8 (1)


Both papers can be obtained as postscript files by ftp:
ftp katla.harvard.edu
login: ftp
password: your email address
cd linster
get filename.ps





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* Christiane Linster                                      *
*                                                         *
* Dept. of Psychology 920       Tel: 1 617 495 3875       *
* Harvard University            Fax: 1 617 495 3728       *
* Cambridge MA 02138            linster at katla.harvard.edu *
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