Varieties of Residual Experience

Abstract

The apparent discrepancy between the results of animal studies and clinical findings on the effects of occipital lobe damage became even greater with the results of animal experiments over the past 20 years in which subjects showed significant residual vision. But there is now evidence that the human subject can also show considerable residual capacity. It appears to be extremely helpful to use forced choice discrimination methods and specific training, as with animals, rather than to depend on verbal commentary by the human subject, who may be unaware of his discriminative capacity. Where man and monkey can be compared, it would appear that they are not qualitatively different, and that residual capacity is biased for detection and localisation rather than identification. Preliminary evidence is presented on the incidence of “blind-sight” and related aspects of residual function, including examination of different dimensions such as form, detection, movement, orientation, and spatial localisation within field defects. Some of these dimensions appear to be dissociable, but each also seems capable of disconnexion from the subject's own commentary and acknowledgement.