Exploring functional and structural plasticity of visual pathways following hemianopia in stroke. (360G-Wellcome-096001_Z_11_Z)

Primary visual cortex damage causes homonymous hemianopia, a loss of visual function on one side of space, which is extremely debilitating and has no effective treatment. Considerable evidence exists, however, to suggest stimuli within the blind hemifield can undergo processing and influence behaviour in a phenomenon known as 'blindsight'. Here we will investigate unconscious visual processing, which may serve as a potential substrate for rehabilitation. Our first goal is to show that patie nts with hemianopia not limited to blindsight undergo structural reorganisation of visual pathways, and establish its evolution following injury. Next, if we are to utilise intact unconscious processing as a route to conscious perception, we must understand its extent and how it occurs. This will be done by investigating the extent of high and low-level information processed unconsciously, in the blind hemifield of stroke patients. Finally, we will look at whether plasticity within the visual brain can be manipulated through targeted rehabilitation. It is still unknown whether the visual system has the same capacity for recovery as other cortical regions. Using stimuli particularly effective at inducing blindsight, we will bring the research together in an exciting pilot study evaluating effects of training on plasticity.