Electrophysiological evidence for dreaming: human cerebral potentials associated with rapid eye movement during REM sleep.

In order to examine the relationship between rapid eye movement (REM) during REM sleep and dreaming, scalp EEGs (Fz, Cz, Pz and Oz) of 4 normal human subjects, time-locked to REM onset, to saccade onset toward fixation targets and to saccade onset in total darkness, were averaged. The results include the following: Three positive potentials were associated with REM: a sharp potential in the parieto-occipital area just before REM onset; a large, slow potential in the vertex area 140-180 msec after REM onset; and a potential in the occipital area 210-280 msec after REM onset. Three positive potentials, one being the so-called EM-antecedent potential and the others being the lambda response, were associated with the waking saccades toward targets: a sharp potential in the parieto-occipital area just before the saccade onset and two potentials in the occipital area with latencies of 140-150 and 260-310 msec from the saccade onset. Only the EM-antecedent potential appearing just before saccade onset was found in association with saccades in total darkness. The similarities between the 3 positive potentials during REM sleep and the lambda response during wakefulness, and the relationship between those potentials and dreaming, are discussed in terms of the neural processes occurring during REM sleep.