A visual tracking machine.

The Visual Tracking Machine is an easily constructed device used for perceptual training with adults and children-with the following diagnoses: cerebral vascular accident, traumatic head injury, cerebral palsy, mental retardation, and spina bifida. It offers activities for the following purpose: development of visual attention and eyemotility, stimulation to cross the midline, compensation iraining for homonymous hemianopsia, one-side neglect, eye-hand coordination, and motor planning. The machine features control over smoothness, speed, and direction of movement of a visual stimulus, eliminates a potentially distracting background, spans the whole visual field, motivates the patient by offering the opportunity for many challenging games, and offers variability in task difficulty. It is sturdily built, relies only on manual power, and is not prone to mechanical breakdown. Used successfully during a one-year trial period, it appears to be a potentially useful adjunct to perceptual training programs. A description of its construction and materials needed are included. Other devices promoting tracking are reviewed in terms of function, source, and availability.