Understanding ‘blindsight’: investigating the pathways that allow those who are clinically blind to ‘see’

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 several groups of participants with hemianopia. 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 and resting state fMRI to provide structural and functional connectivity 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 showing a link between neurochemistry and visual performance in area MT. I aim to demonstrate how multi-modal MRI can provide converging evidence to identify regions to target for rehabilitation.

Holly Bridge is a professor of Neuroscience at the Nuffield Department of Clinical Neurosciences of the University of Oxford (UK), she is one of the leading experts in clinical visual neuroscience.

The DEC is delighted to host Prof. Bridge as invited professor starting from June 17th 2024. During her visiting time, Holly will give a series of four lectures.

• 17/06/24, 14h30-16h30, salle Jaurès

Understanding ‘blindsight’: investigating the pathways that allow those who are clinically blind to ‘see’

• 25/06/24, 14h30-16h30, salle Ribot

The potential for visual rehabilitation following stroke to the visual cortex

• 02/07/24, 14h30-16h30, salle Ribot

Understanding the development of the human brain in the absence of vision

• 09/07/24, 14h30-16h30, salle Ribot

Investigating the human binocular visual system using multi-modal magnetic resonance imaging