Automatic segmentation of REM sleep into three substages

The research aimed to introduce and test an automatic method for segmentation of REM sleep into three substages, respectively characterized by: enhancement of rapid eye movements; selective enhancement of slow eye movements (SEMs); reduction in the amount of eye movements. This objective was suggested by two kinds of data reported in the literature: distinction between phasic and tonic REM sleep, and remarkable presence of SEMs during REM sleep.