ABINEP M4-project 3: Impact of vision loss on visual search

Vision loss affects the ease with which we can explore the environment with eye movements. For instance, patients suffering from a central scotoma place saccade targets into the scotoma region until they have learned to use an extrafoveal retinal location as a saccadic reference point. This often takes months during which the patients suffer from inefficient exploration patterns with few saccades and abnormally wide attentional foci.

Other patients use retinal implants that provide them with residual vision in a small part of their visual field. Depending on the system used, the implants enable eye movements or only head movements to explore the environment. The impact of this limitation on visual search of the environment has only scarcely been investigated.

In the present project, we aim to investigate the impact of partial vision loss on visual search with eye-tracking and functional magnetic resonance imaging. Eye-tracking is used to simulate vision loss with gaze-contingent simulation of vision loss, e.g. with simulated scotomata. In combination with fMRI, we aim to investigate changes in visual search processes on the one hand and changes in the neural representation of the environment on the other hand.