Additivity of aftereffects of maintained head and eye rotations: An alternative to recalibration

Seven groups of 10 subjects each were exposed to various combinations of left and right head and eye rotations for a period of 10 min. Both head and eye produced significant aftereffects of prior position as measured by pointing at a visible target with the unseen hand, but there was no significant interaction. Thus, aftereffects of sustained head and eye rotation were shown to be additive and to account fully for the results of Craske and Crawshaw (1975). Eye muscle potentiation rather than recalibration may be assumed to be the cause of the altered direction of gaze resulting from exposure to displacing prisms.