On Interocular Transfer of the Movement Aftereffect in Individuals with and without Normal Binocular Vision

Abstract

The duration of the movement aftereffect was measured in twenty-four normally binocular subjects and in eighteen subjects who lacked stereopsis as a consequence of childhood strabismus. Aftereffects were generated monocularly and binocularly, and compared to those which occurred after adaptation of one eye and testing with the other. Normal subjects were categorized on two indices of eye dominance, which involved sighting and rivalry tests. The monocular-aftereffect durations were slightly longer when the dominant eye was used, and interocular transfer from the dominant eye to the nondominant eye was greater than the transfer in the reverse direction; however, these differences were not statistically significant. The results from the strabismic subjects suggested that they fell into two distinct groups: one group (seven of the eighteen subjects) experienced no interocular transfer in either direction; the other group did yield some interocular transfer, and it was generally greater after adaptation of the dominant eye and testing the nondominant eye than in the reverse direction. Six of the seven subjects who failed to show any transfer still had misalignment of the visual axes, but this was not the case in any of the subjects exhibiting transfer.