Horizontal Connectivity and Prediction of Coherences in the Integration of Contour and Retinal Flow in the Primary Visual Cortex – Horizontal-V1

The Horizontal-V1 project aims at understanding the emergence of sensory predictions linking local shape attributes (orientation, contour) to global indices of movement (direction, speed, trajectory) at the earliest stage of cortical processing (primary visual cortex, i.e. V1). We will study how the long-distance "horizontal" connectivity, intrinsic to V1 and the feedback from higher cortical areas contribute to a dynamic processing of local-to-global features as a function of the context (eg displacement along a trajectory; reafference induced by eye-movements...). We will search to characterize the dynamic processes based on lateral propagation in V1, through which spatio-temporal inferences (continuous movement or apparent motion sequences) facilitating spatial ("filling-in") or positional ("flash-lag") future expected responses may be generated. The project will use a variety of animations of local oriented stimuli forming, according to their local to global configuration, spatial and temporal properties, predictable global patterns. We will measure the cortical dynamics at two scales of neuronal integration, from micro- (intracellular, SUA) to meso-scopic levels (multi-electrode arrays (MEA) and voltage sensitive dye imaging (VSDI)) in the anesthetized (cat, marmoset) and awake fixating animal (macaca mulata). In a second step, we will combine these multi-scale observations to constrain a structuro-functional model of low-level perception, integrating the micro-meso constraints. Two laboratories will participate in synergy to the project: UNIC-Gif (Dir. Yves Frégnac, DRCE2 CNRS, coordinator) and INT-Marseille (InVibe Team Dir. Frederic Chavane, DR2 CNRS).