STATIONARITY DURING REM SLEEP IN OLD ADULTS

Visually, Rapid Eye Movement (REM) sleep is characterized by REMs, muscle atonia and desynchronized EEG activity. When quantitative analyses of the signals are carried out, usually, non-linearity and non-stationarity are assumed without an adequate analysis, especially in Old Adults (OA). Among the weak stationarity tests, the Priestley-Subba Rao (PSR) test calculates a local spectra that is valid only for punctual moments in time. A series of smoothed frequency filters give information of the time the local spectra is calculated. In here, weak REM sleep stationarity by the PSR test was compared to that from Wakefulness (W) and Non-REM (NREM) sleep.