Structure of receptive fields in a computational model of area 3b of primary sensory cortex

Georgios Is. Detorakis, Nicolas P. Rougier
Front. Comput. Neurosci.. 2014-07-28; 8:
DOI: 10.3389/fncom.2014.00076

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1. Front Comput Neurosci. 2014 Jul 28;8:76. doi: 10.3389/fncom.2014.00076.
eCollection 2014.

Structure of receptive fields in a computational model of area 3b of primary
sensory cortex.

Detorakis GI(1), Rougier NP(2).

Author information:
(1)Laboratoire des Signaux et Systèmes, Supélec Gif-sur-Yvette, France.
(2)INRIA Bordeaux Sud-Ouest Bordeaux, France ; Institut des Maladies
Neurodégénératives, Université de Bordeaux, Centre National de la Recherche
Scientifique, UMR 5293 Bordeaux, France ; LaBRI, Université de Bordeaux, Institut
Polytechnique de Bordeaux, Centre National de la Recherche Scientifique, UMR 5800
Talence, France.

In a previous work, we introduced a computational model of area 3b which is built
upon the neural field theory and receives input from a simplified model of the
index distal finger pad populated by a random set of touch receptors (Merkell
cells). This model has been shown to be able to self-organize following the
random stimulation of the finger pad model and to cope, to some extent, with
cortical or skin lesions. The main hypothesis of the model is that learning of
skin representations occurs at the thalamo-cortical level while cortico-cortical
connections serve a stereotyped competition mechanism that shapes the receptive
fields. To further assess this hypothesis and the validity of the model, we
reproduced in this article the exact experimental protocol of DiCarlo et al. that
has been used to examine the structure of receptive fields in area 3b of the
primary somatosensory cortex. Using the same analysis toolset, the model yields
consistent results, having most of the receptive fields to contain a single
region of excitation and one to several regions of inhibition. We further
proceeded our study using a dynamic competition that deeply influences the
formation of the receptive fields. We hypothesized this dynamic competition to
correspond to some form of somatosensory attention that may help to precisely
shape the receptive fields. To test this hypothesis, we designed a protocol where
an arbitrary region of interest is delineated on the index distal finger pad and
we either (1) instructed explicitly the model to attend to this region
(simulating an attentional signal) (2) preferentially trained the model on this
region or (3) combined the two aforementioned protocols simultaneously. Results
tend to confirm that dynamic competition leads to shrunken receptive fields and
its joint interaction with intensive training promotes a massive receptive fields
migration and shrinkage.

DOI: 10.3389/fncom.2014.00076
PMCID: PMC4112916
PMID: 25120461

Auteurs Bordeaux Neurocampus