Saccadic adaptation in neurological disorders.

The role of saccadic adaptive processes in recovery from the effects of various neurological disorders, such as myasthenia gravis, extraocular muscle palsies, and age-related macular degeneration, is reviewed. Studies of clinical populations (e.g. cerebellar disease, mild closed head injury, and opsoclonus) in which intrasaccadic displacement of visual targets has been used to stimulate adaptation are also reviewed. Our own data from such a study of 12 subjects with Parkinson's disease are presented, showing that visually guided adaptation is preserved in PD while memory-guided adaptation is impaired. This supports a model in which different brain regions subserve adaptation in different tasks.