Visual masking during pursuit eye movements.

In three experiments, targets and masking stimuli were briefly flashce while observers visually tracked a moving dot. Masking stimuli were more effective when they appeared to be in the same place as the target but stimulated different parts of the retina than when they stimulated the same parts of the retina but appeared displaced because of of an intervening pursuit eye movement. Visual masking during pursuit eye movements thus depended on the apparent position of the stimuli, not their retinal positions as such, which is in disagreement with previous studies of visual masking during saccadic eye movements. The apparent conflict can be explained in terms of the functional significance of visual masking in tracking and saccardic movements: Retinal position masking after saccadic eye movements may erase previous images, and apparent position masking during pursuit eye movements may make moving targets more visible.