Sleep 101
Sleep, unlike death, is characterized by a reversible state of unresponsiveness. Sleep is separated into two states, one of non-rapid eye movements (NREM) and one of rapid eye movements (REM).
Consider the stages of NREM sleep to be “synchronous” as far as the EEG waveforms are concerned. Large slow eye movements may be seen and on EEG, the appearance of sleep spindles and K-complexes:
