GAZE AND RETINAL-IMAGE-STABILITY IN 2 KINDS OF SEQUENTIAL LOOKING TASKS

Eye and head movements used to keep the gaze on target were examined a s unrestrained seated subjects performed two tasks: (1) tapping sequen ces of 3-D targets, and (2) only looking at sequences of 3-D targets. Large differences were observed in the head/eye coordination patterns used in each task. During tapping, the head moved quickly and continuo usly. Retinal-image speeds were relatively high (up to 5 degrees/s). D uring looking-only, the head moved more slowly and almost came to rest between gaze-shifts. Retinal image velocities between gaze-shifts wer e 60-77% lower during looking-only than during tapping. Conclusion: co ordinated eye/head patterns are adjusted to satisfy the demands of a p articular task. These adjustments affect low-level oculomotor mechanis ms between as well as during the gaze shifts, themselves (reported pre viously). (C) 1998 Elsevier Science Ltd. All rights reserved.