Joseph Cohen

Professor Emeritus of Psychology
Vision and visual perception; neuropsychology of vision and action; color perception; perceptual illusions; interactions of color in visual art

My research interests are generally in the area of vision and visual perception. Currently, I am exploring how we use visual information depending on whether we are trying to judge what the objects around us are or whether we are acting on those objects, for example, walking towards them or grasping them. Perception and action seem to use visual information in different ways.

Some of the strongest evidence comes from stroke patients. Patients with damage in the inferotemporal cortex of the brain are unable to use vision to recognize the objects in their environment, yet they can accurately reach out and grasp them.

Patients with damage to the posterior parietal cortex can recognize objects, but they cannot readily move towards them or grasp them. My research students and I are investigating this dissociation in intact subjects by comparing perceptual and visuomotor responses to visual illusions.

In other work on color perception I have been investigating individual differences in the time course of color change following color adaptation (exposure to another colored light stimulus) and during recovery from that adaptation, that is, after the colored adapting light is turned off. I also have an abiding interest in psychology and art, particularly in the use of color interactions by visual artists.

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Recent Publication

Radoeva, P. D., Cohen, J. D., Corballis, P.M., Lukovits, T. G., and Koleva, S. (2005). Hemispheric asymmetry in a dissociation between the visuomotor and visuoperceptual streams. Neuropsychologia, 43, 1763-1773