Sonja Hofer (UCL)

Speaker

Sonja Hofer
Sainsbury Wellcome Center
United Kingdom

Abstract

The classical model of sensory information processing is based on a hierarchical organization of feed-forward connections from one brain region to the next. However, perception is not only dependent on the sensory feed-forward input but also on the context in which a given stimulus occurs, such as an animal’s behavioral state, its knowledge, expectations and actions. Such contextual, top-down information can strongly modulate sensory responses and influence how sensory information is interpreted and perceived. My lab studies the circuits supporting sensory information processing, how different signals are integrated by these circuits and the mechanisms by which context and behavioral relevance influence visual processing and visually-guided behaviour.

While sensory perception is thought to mainly rely on cortical circuits, higher-order sensory nuclei in the thalamus interconnect extensively with all sensory cortical and many subcortical areas. In the first part of my talk, I will present our efforts to understand the role of higher-order thalamocortical interactions during sensory processing, with a focus on what information these pathways convey to different cortical areas and whether they link sensory signals with internal, contextual information. The second part of my talk focuses on long-range inhibitory circuits from a subthalamic nucleus, the ventral lateral geniculate nucleus. I will show that this nucleus can flexibly regulate visually-evoked defensive behaviour by integrating visual signals with the internal state of the animal and the knowledge it has about its environment.