Influence of cranial radiation by high-energy protons on the visuo-motor behavior of nonhuman primates

The visually driven instrumental conditioning on a one monkey (Macaca mulatta) was conducted after single-dose cranial irradiation with high-energy protons. The monkey executed saccades toward the visual stimuli and then performed the movement with ipsilateral hand correspondingly to their location in a right or left visual hemifield. The rate of correct responses with dominant right hand exceeded the rate of such responses with left hand and decreased briefly two months after irradiation. Then a month later, the rate of correct right-hand responses returned to the level before irradiation. No significant dynamics was revealed for the rate of correct left-hand responses. The proton irradiation effect on right-hand responses suggests possible short-term disturbances in the eye-hand coordination for right handedness while the visual perception remains resistant.