An outline of the symptoms after lesions on the visual dorsal stream

Abstract

  Converging evidence indicates that there are three streams of information processing in man: 1) ventral stream, which directed to the temporal lobe for processing shape and color of the object to identify them and to retrieve the knowledge of them; 2) ventro-dorsal stream, which directed to the inferior parietal lobule for processing object location and movement to form conscious representation of objects; 3) dorso-dorsal stream, which directed to the intraparietal sulcus and the superior parietal lobule for processing location movement and shape of the object to control actions toward the object unconsciously. Lesions on the ventro-dorsal stream can produce akinetopsia, or hemispatial neglect. Lesions on the dorso-dorsal stream can produce visuomotor ataxia defective prehension or orienting disability of oneʼs own body. Responsible cites and features of these symptoms are discussed with reference to the functions of those two streams.