USING THE EYE-MOVEMENT SYSTEM TO CONTROL THE HEAD

We tested the hypothesis that A.I., a subject who has total ophthalmop legia, resulting in a lack of eye movements, used her head to orientat e in a qualitatively similar way to eye-based orientating of control s ubjects. We used four classic eye-movement paradigms and measured A.I. 's head movements while she performed the tasks. These paradigms were (i) the gap paradigm, (ii) the remote-distracter effect, (iii) the ant i-saccade paradigm, and (iv) tests of saccadic suppression. In all cas es, A.I.'s head saccades were qualitatively similar to previously repo rted eye-movement data. We conclude that A.I.'s head movements are pro bably controlled by the same neural mechanisms that control eye moveme nts in unimpaired subjects.