How do we look while dreaming: binocular coordination of eye movements during REM sleep

In everyday life while shifting our gaze to objects of interest, our eyes are highly conjugated (Hering’s law, 1868). It is unknown whether binocular control is active during human REM sleep. Monkey REM sleep eye movements could be observed that did not follow Hering’s law. Recent human electrophysiological and functional imaging studies indicate active processing of dreamed images during REM sleep. Two different hypotheses exist: REMs (i) are indicators of spontaneous eye muscle contractions or (ii) reflect scanning dreamed images. We studied eye movements in REM sleep in six subjects using scleral search coils…