Adaptation of the Simple or Complex nature of V1 receptive fields to visual statistics
Résumé
Receptive fields (RFs) in primary visual cortex (V1) are categorized as Simple or Complex, depending on their spatial selectivity to stimulus contrast polarity. We studied the dependence of this classification on visual context by comparing, in the same cell, the synaptic responses to three classical RF mapping protocols: sparse noise, ternary dense noise and flashed Gabor noise. Intracellular recordings show that the relative weights of Simple-like and Complex-like RF components are scaled such as to make the same RF more Simple-like with dense noise and more Complex-like with sparse or Gabor noise stimulations. However, once these context-dependent RFs are convolved with the corresponding stimulus, the balance between Simple-like and Complex-like contributions to the synaptic responses appears invariant across input statistics. This normalization of the linear/nonlinear input ratio suggests a novel form of homeostatic control of V1 functional properties, optimizing the network nonlinearities to the statistical structure of the visual input.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)
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