Ocular fixation during eye and head tracking with and without a visual cue to head position.
OBJECTIVE
This experiment had two purposes. The first purpose was to compare ocular fixation during eye tracking, head tracking, and head tracking with a visual cue to head position. The second purpose was to compare head tracking with and without a visual cue to head position.


METHODS
Eleven subjects tracked a pseudo-random laser target in three conditions. In one condition (Condition 1), subjects tracked the target primarily with the eyes. In a second condition (Condition HT), subjects tracked the target with the head but no visual cue to head position was provided. In the final condition, subjects tracked the target with the head and were given a visual cue to head position (Condition HR).


RESULTS
On average, ocular fixation was worst in Condition HR and similar in Condition 1 and Condition HT. Mismatches in target and head velocity greater than 60 degrees x sec(-1) occurred more frequently in Condition HR than in Condition HT.


CONCLUSIONS
Ocular tracking of a pseudo-random target is adversely affected in a minor way by head movement, but tracking declines significantly when head tracking is performed with a visual cue to head position. In terms of velocity matching, head tracking is also adversely affected by a head position cue.
Fogt
Nick
N
Ohio State University College of Optometry, Columbus 43218-2342, USA. Fogt.4@osu.edu
Luthman
Nicholas
N
D000328:Adult; D000337:Aerospace Medicine; D003463:Cues; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008297:Male