Visual properties of neurons in the thalamus and striopallidar complex of the human brain.

In parkinsonian patients diagnosed and treated with the aid of long-term intracerebral electrodes, neuronal impulse activity (NIA) was recorded in different nuclei of the thalamus and striopallidar complex during visual testing for orientation sensitivity. Neuronal populations responding only to the presented stimuli with specific angular orientations have been revealed. Orientation-selective neurons have been found with significant responses in NIA observed to the same angular orientations of stimuli during 90 degrees head tilts. It is hypothesized that the visual perception constancy can be maintained with the participation of cerebral nuclei containing such neurons on the basis of convergence of motor, somatosensory and visual information.