Disconjugate ocular motor adaptation in rhesus monkey

We report a model for inducing disconjugate, orbital-position dependent, ocular motor adaptation in the rhesus monkey. Animals wore a combination of laterally-displacing prisms placed in front of one eye calling for a discrete change in ocular alignment when the eyes reached particular orbital positions. After wearing the prism combination the animals developed adaptive changes both in static alignment during fixation and in dynamic alignment during eye movements. These changes persisted with only one eye viewing and so became independent of the immediate presence of disparity cues. There were, however, imperfections in the adaptive responses; the changes in the innervation were gradual across the prism edge, not abrupt as required. This finding may reflect inherent limitations in the capability for disconjugate adaptation.