Visual Physiology

The Vision Laboratory's research investigates how the brain makes sense of the world viewed by the eye. Insects are ideal for tackling this problem at theoretical, physiological and behavioural levels. With a visual system that accounts for as much as 30% of the lifted mass, some flying insects invest more in vision than any other animal. What happens to the abundance of information collected by such large eyes? How has the brain evolved to optimally extract the features from scenes that are most relevant to the behaviour adopted? 

A territorial encounter between two male hoverflies (Eristalis tenax)

To address these questions, we use electrophysiological recordings from neurons in the brain of large insects such as dragonflies and hoverflies. Many of these insects have spectacular aerobatic visual behavior during which they pursue targets (either prey or in the case of territorial flies, rival males or potential mates). Among other discoveries, our lab has shown that the insect visual system employs processing strategies similar to those in the mammalian cortex, and that insects see many of the same visual illusions that humans do. Many of our recent experiments aim at understanding these illusions at a neurophysiological level using in-vivo recordings on intact insects, focussing particularly on physiological processes underlying adaptation and short-term plasticity. Other experiments focus on neural pathways involved in discriminating movement of objects amidst complex visual texture ('background clutter').

We are also collaborating with industry to develop robust models for adaptive motion detectors, based on insect vision, for implementation in silicon hardware. We have succesfully constructed silicon chips that robustly mimic the adaptive motion processing of biological visual pathway. Applications for this technology include the aerospace industry, guidance systems for miniature autonomous vehicles and for embedded collision avoidance sensors that could be incorporated in future motor vehicles. We are also collaborating with neural stem cell researchers to develop an interface between computer chips and living neurons that may one day allow us to develop bionic eye devices that connect our motion sensing chips directly to the human brain.