Helmholtz Lecture Holly Bridge, Investigating the pathways underlying residual vision in hemianopia

Helmholtz Lecture: 25 January 2019, from 14.45 – 15.45, Academiegebouw – Aula, Domplein 29 in Utrecht

January 25th , 2019 –Holly Bridge,  Nuffield Department of Clinical Neurosciences, University of Oxford, UK

“Investigating the pathways underlying residual vision in hemianopia”

Damage to the primary visual cortex leads to loss of the visual field contralateral to the damaged cortex. However, in spite of this loss, some patients are still able to detect visual information about stimuli presented within their blind field. A growing area of research aims to exploit this residual visual function to try to improve visual performance through rehabilitation programmes stimulating the blind field. However, to optimise such programmes it is important to understand the pathways through which this information is conveyed. 

Here I will outline a series of magnetic resonance imaging studies in which we attempted to elucidate these pathways in a group of hemianopic patients. Firstly I will explain how our functional MRI studies use the specific pattern of response to visual stimulation in different visual areas to uncover candidate pathways. I will use diffusion-weighted data to provide support for a pathway between the lateral geniculate nucleus and motion area MT that is consistently intact only in patients showing blindsight abilities. Finally, I will present our most recent data in which we find further support for this pathway using functional connectivity analysis.