A parsimonious computational model of visual target position encoding in the superior colliculus.
The superior colliculus (SC) is a brainstem structure at the crossroad of multiple functional pathways. Several neurophysiological studies suggest that the population of active neurons in the SC encodes the location of a visual target to foveate, pursue or attend to. Although extensive research has been carried out on computational modeling, most of the reported models are often based on complex mechanisms and explain a limited number of experimental results. This suggests that a key aspect may have been overlooked in the design of previous computational models. After a careful study of the literature, we hypothesized that the representation of the whole retinal stimulus (not only its center) might play an important role in the dynamics of SC activity. To test this hypothesis, we designed a model of the SC which is built upon three well-accepted principles: the log-polar representation of the visual field onto the SC, the interplay between a center excitation and a surround inhibition and a simple neuronal dynamics, like the one proposed by the dynamic neural field theory. Results show that the retinotopic organization of the collicular activity conveys an implicit computation that deeply impacts the target selection process.
Institut de Neurobiologie de la Méditerrantée, INSERM, UMR 901, Aix-Marseille University, Marseille, France. wtaouali@gmail.com.
Wahiba
W
Taouali
Institut de Neurosciences de la Timone, CNRS, UMR 7289, Aix-Marseille University, Marseille, France.
Laurent
L
Goffart
INRIA Bordeaux Sud-West, Talence, France.|LaBRI, Université de Bordeaux, Bordeaux INP, UMR 5800, Centre National de la Recherche Scientifique, Talence, France.|Institut des Maladies Neurodégénératives, Université de Bordeaux, UMR 5293, Centre National de la Recherche Scientifique, Bordeaux, France.
Frédéric
F
Alexandre
INRIA Bordeaux Sud-West, Talence, France.|LaBRI, Université de Bordeaux, Bordeaux INP, UMR 5800, Centre National de la Recherche Scientifique, Talence, France.|Institut des Maladies Neurodégénératives, Université de Bordeaux, UMR 5293, Centre National de la Recherche Scientifique, Bordeaux, France.
Nicolas P
NP
Rougier
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003198:Computer Simulation; D006801:Humans; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D017711:Nonlinear Dynamics; D010775:Photic Stimulation; D013477:Superior Colliculi / Q000166:cytology / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception
Computational neuroscience; Neural field; Superior colliculus; Topology; Visual target