Présentation
Neuroscience Seminar Series
Dr Georg Keller
Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
” Active sensory processing in mouse visual cortex “
Invité par les étudiants du Département – Contact : anne.grelat@pasteur.fr
Abstract:
Seeing, quite intrinsically, is an active process. Most visual input is the direct
consequence of self-generated movements. In spite of this, visual processing is
often analyzed in a computational framework of a representation: neurons are
described as feature detectors. I will argue that the computational function of
layer 2/3 of primary visual cortex of the mouse is that of a comparison between
predicted and actual visual input. We can show that there is a dense, retinotopic
projection from anterior cingulate cortex to L2/3 of primary visual cortex
that conveys a prediction of visual flow based on motor output. We can also
show that visual cortex combines these motor-related predictions with visual
signals to generate mismatch responses that signal a deviation from expectation.
Mismatch signals are likely generated through a combination of an excitatory
feedback prediction and a somatostatin-interneuron mediated inhibitory
feed-forward visual input. Lastly, we can show that both feedback predictions
and mismatch responses are critically dependent on sensorimotor experience.
In this way the function of the visual system in cortex may be the generation
of an internal model of the visual environment that is continuously compared
to and updated by visual input.