Section: Scientific Foundations

Visual perception modeling

Visual perception is the result of complex dynamical interaction between cortical maps. Interestingly, in many situations, the dynamics of perceptual effects show striking similarities when observed at neuronal, psychophysical, and oculomotor levels. Based on the inter-relation and complementary insights given by those dynamics, we can investigate how basic mechanisms of dynamical cortical processing can be incorporated in dynamical models. This work requires to understand the behaviour of dynamical systems involving, e.g., the interaction between multiple areas, the role of synaptic plasticity, the effects of delays or slow-fast interaction, which are observed at the neuronal level. Thus, theoretical contributions can have a major impact on the development of visual perception models that are able to not only explain but also predict perceptual effects.

For example, our group is developing models of motion perception, in collaboration with Institut des Neuroscience de la Timone (Marseille, France). Our recurrent models of motion integration, involving V1 and MT cortical maps. Proposing a simple readout mechanism, we reproduce not only motion perception but also the dynamics of smooth pursuit eye movements on various line figures and gratings viewed through different apertures. Our models can also solve various contextual problems where extrinsic junctions should be eliminated, without relying on complex junction detectors or depth computation. We now investigate neural fields formulations which enable to consider further perceptual effects such as, e.g., multistability. Finally, one important goal of our contribution in this area is to formalize the comparison against visual performance and also to confront our results to computer vision when it is possible.