A parsimonious computational model of visual target position encoding in the superior colliculus

Wahiba Taouali (1) , Laurent Goffart (1) , Frédéric Alexandre (2, 3, 4) , Nicolas P. Rougier (2, 3, 4)

1 INT - Institut de Neurosciences de la Timone
2 IMN - Institut des Maladies Neurodégénératives [Bordeaux]
3 LaBRI - Laboratoire Bordelais de Recherche en Informatique
4 Mnemosyne - Mnemonic Synergy

The superior colliculus (SC) is a brain-stem 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 retino-topic organization of the collicular activity conveys an implicit computation that deeply impacts the target selection process.

Domaines: Neurosciences

Wahiba Taouali, Laurent Goffart, Frédéric Alexandre, Nicolas P. Rougier. A parsimonious computational model of visual target position encoding in the superior colliculus. Biological Cybernetics (Modeling), 2015, 109 (4-5), ⟨10.1007/s00422-015-0660-8⟩. ⟨hal-01201785⟩