The continuing emphasis of this project has been to collaborate with the Laboratory of Sensorimotor Research in studying oculomotor disorders in human subjects. The computerized methods for recording and analysing eye movements pioneered by the LSR have been applied to a variety of clinical eye movement disorders. An ongoing series of experiments established a set of normative values for human performance of several of the oculomotor subsystems, particularly the saccadic and pursuit systems. The major advances in these areas were extensions of neurophysiological work done in the LSR on non-human primates. The major findings included a description of the motion processing needed to keep the eyes following a moving target by saccades and pursuit movements. The human brain requires about 75 milliseconds to begin to follow moving stimuli, but an accurate assessment of the stimulus velocity develops over an additional 100 milliseconds. Studies on the role of the basal ganglia in eye movement processing continued with a study of patients with progressive supranuclear palsy, with particular attention to the abnormalities of vertical eye movements in spite of relatively preserved horizontal eye movements. These patients were also examined for attentional deficits. Additional ongoing projects included following patients with a variety of neurological disorders of metabolism such as Gaucher's Fabry's and Niemann-Pick disease.
