By flickering stimuli on a monitor screen it is possible to 'frequency tag' the electrical responses they generate in the brain. This technique can be used to study the way that patterns interact with each other in the early visual pathways - allowing us to understand the fundamental computations underlying visual processing.

fMRI allows us to image visual cortex with high spatial resolution - we can see where visual stimuli are represented in cortex and what happens to those representations as they pass through the early visual areas. Using fMRI we are asking how the strength of one visual stimulus is altered by its surroundings and by higher level influences such as attention.

 

We are translating our electrophysiology techniques to other species. In particular, we are examining visual responses in fruit flies (Drosophila Melanogaster). These organisms can be excellent models of human neurological diseases and our current projects are focused on the changes in visual gain control that accompany Parkinson's Disease and some types of epilepsy.