CHANGES IN STATE OF CONSCIOUSNESS AND PATTERNS OF EYE MOVEMENTS

Abstract

The patterns of spontaneous eye movements and those induced by electric stimulation of the cerebrum change in a predictable manner as the state of consciousness is depressed by anesthesia, sleep, or by the deterioration associated with prolonged experiments. The state of consciousness is as important as the locus stimulated and the parameters of the stimulus in determining the pattern of an electrically induced eye movement. Oblique and vertical eye movements, though common in the alert state, are difficult or impossible to observe in the anesthetized animal. Eye centering is uncommon in the alert preparation but frequent when consciousness is partially depressed. The effects of consciousness upon spontaneous ocular motions and upon those induced by electric stimulation of cerebrum suggest the following similarities between eye movements and other bodily movements: (a) the size of the excitable cortical area is greater in the alert preparation, (b) the response from a cerebral point may change as the alertness or wakefulness lessens or increases, (c) background activity other than the state of alertness (e.g. vision) may affect the pattern of elicited and spontaneous responses.