Separate channels for visuomotor transformations in the pigeon.

Since the discovery of two parallel visual systems in humans and primates there has been much speculation about their functions. One prominent current model, suggesting independent processing of visual information for perception and action, is supported by neuroanatomical, electrophysiological, neurobehavioral, and human clinical data. Furthermore, studies of visuomotor behavior in amphibians and non-primate mammals indicate that neural processing of action-related behavior is mediated by separate neuronal channels thus suggesting an evolutionary principle in the organization of visuomotor behavior. If such an evolutionary principle operates it should also apply to birds. I will present and discuss behavioral and behavioral physiological evidence that action-related behavior in pigeons like pecking, grasping and control of gaze is controlled via separate neuronal channels subserving visuomotor functions.