VISUAL-FIELD ENLARGEMENT BY NEUROPSYCHOLOGICAL TRAINING OF A HEMIANOPIA PATIENT

A 58-year old hemianopsia patient was submitted to a two-fold neuropsy chological training in order to enhance visual functions in the affect ed part of his visual field. At first, the visual field was measured p erimetrically, to serve as a starting measurement with which after-mea surements could be compared. Then, the first training was started: the border area between the intact and the defect visual field was being stimulated by small light spots. The training consisted of repetitive detection threshold measurements. After 27 one-hour sessions, the visu al field was being measured again. The visual field appeared to have b een enlarged 5 to 12 degrees in the direction of the affected hemifiel d and contrast-sensitivity thresholds to have been decreased almost at every point in the stimulus-array. Then, a second training started; a n eye-movement training. Again, the border area, now shifted outwards, was stimulated. This time, the stimulus concerned a short presentatio n of light (< 200 msec.) after which the subject, to the best of his a bilities had to make an eye-movement to the perceived stimulus-site. A lso, he had to categorize the quality of his perception as well as the direction in which the stimulus was thought to be perceived. After 30 sessions, the visual field appeared to have 'grown' just a little bit more, but this seems not to be a significant enlargement. More import ant, the number of detected stimuli in the supposed 'blind' area had i ncreased, as had the accuracy of the localization of the stimuli. Prel iminary results of the detection training of a second subject, also 58 years of age, are presented. Finally, planned actions are discussed.