Internal models of the environment in mouse cortex

Summary

Date: 
April 25, 2018 - 1:00pm
Location: 
Northwest Building Room 243
About the Speaker
Name: 
Georg Keller
Speaker Affiliation: 
Friedrich Miescher Institute for Biomedical Research (FMI)

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 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 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.