Propagating waves in visual cortex and their computational role
Abstract: Propagating waves have been observed in various in vivo and in vitro preparations but their role still remains obscure. Propagating waves were also seen in physiological conditions, such as in primary and secondary visual cortical areas of awake monkey (Muller et al., Nature Commun. 2014), suggesting they may play a role in vision. Here, using voltage-sensitive dye imaging in awake monkey V1, we show that colliding propagating waves always sum sublinearly and mediate a suppressive effect. By using a probabilistic decoder, we show that this suppression enables to dis-ambiguate stimuli. These features were also captured by computational models, using a mean-field approach. The model suggests that the suppressive effect depends on two ingredients, the fact that inhibition has a higher gain than excitation, and the fact that they combine via conductance-based interactions. We conclude that propagating cortical waves are involved in the processing of visual information.
Supported by the CNRS and the European Community (Human Brain Project).