Blindness to form from motion despite intact static form perception and motion detection.
We studied the motion perception, including form and meaning generated by motion, in a hemianopic patient who also had visual perceptual impairments in her seeing hemifield as a result of a lesion in ventral extrastriate cortex. She was unable to recognise 2- or 3-dimensional forms, and even borders, generated by motion alone, failed to recognise mimed actions or the Johannson 'biological motion' display, and ceased to recognise people well-known to her when they moved. Her performance with static displays, although impaired, could not explain her inability to perceive shape or derive meaning from moving displays. Unlike a motion-blind patient, she can still see and describe the motion, with the exception of second-order motion, but not what it creates or represents.
Cowey
A
A
Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, UK. alan.cowey@psy.ox.ac.uk
Vaina
L M
LM
D000368:Aged; D001921:Brain / Q000473:pathology; D002544:Cerebral Infarction / Q000473:pathology / Q000523:psychology; D003118:Color Perception / Q000502:physiology; D003867:Depth Perception / Q000502:physiology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009039:Motion Perception / Q000502:physiology*; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000473:pathology / Q000523:psychology*; D010775:Photic Stimulation; D020521:Stroke / Q000473:pathology / Q000523:psychology