Similarity of Eye Movement Characteristics in REM Sleep and the Awake State

The eye movements of REM (Rapid Eye Movement) sleep have been reported to be slower, i.e., to show reduced velocities, compared to those of the awake state. We demonstrated that REM sleep eye movements are in fact similar in velocity to awake state eye movements under the condition of no visual input (eyes open or closed). Furthermore, we observed that oculomotor velocities and trajectories in REM sleep are more similar to head-unrestrained (normal vision) than head-restrained (bite board) conditions in the awake state. The DC electro-oculogram (EOG) was utilized for all measurements. Both head-unrestrained and REM sleep eye movements contained looped trajectories not present when the head was immobilized. Eyelid closure had little effect beyond that of total darkness. Recumbent body position did not significantly alter velocity characteristics. These data indicate that the eye movements of REM sleep are more congruent with the hallucinated locomotor activity of the dream than with the postural immobility’ of the dreamer.