Experimental testing of a sensorimotor origin of saccadic suppression

Details

Supervisors

Crevecoeur, Frédéric ; Lefèvre, Philippe

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil biomédical

Abstract

Saccades are essential eye movements for our environment construction but such rapid and numerous movements are subject to phenomena which have repercussions on perception. It has been known for a while that around the saccade timing there exist a lost of visual sensitivity, this effect is known as saccadic suppression. Its origin and mechanism are still subject to debate but the prevailing hypothesis suggests that saccadic suppression is a phenomenon purely related to the stabilisation of perception. However, elements such as the timings of suppression make this assumption inconsistent. Here for this work we propose to test a novel hypothesis which seems to respond to the critics. This hypothesis claims that saccadic suppression could arise from an efficient sensorimotor calculation and consequently that there could be a cross talk between perception and control in the brain. In other words this hypothesis states that perception can be impaired by sensorimotor control, consequently a way to challenge it is to consider that control might be impaired by perception. To do so, we realised an experiment with several subjects where we tried to disrupt their saccade movement with flashed stimuli. We analysed the recorded eye movements of each subjects and particularly their saccade main sequences. Many very uncommon anomalies in these saccades were found which is in agreement with what the hypothesis stated. Our results tend thus to confirm the sensorimotor origin for the saccadic suppression. However future analyses are still needed to clarify the link between these anomalies and other parameters.