A long range evaluation of complex perception was made on 25 Parkinson patients undergoing basal ganglia surgery using determinants from Rorschach protocols. The patients were tested preoperatively and postoperatively at 5 days, 2 months, 6-8 months, and 1½-2 years. Changes were confined mainly to color and movement variables. In the acute period there was enhanced response to color and movement and, conversely, in the chronic period there was subdued response. There was essentially no change in the total number of responses, or no deterioration in the form quality of the responses. It was concluded that the lesion affects predominately perceptual organizations rather than productivity or perceptual accuracy.Abstract Teaser