[The history of observations and some methodological features of the studies on local sleep]

The phenomenon of local sleep, a concept that has come into somnology relatively recently, has been attracting more and more attention of researchers. Under this name, two groups of phenomena are considered. The first is the appearance in different parts of the cerebral cortex of different EEG patterns during general sleep. The second is the disconnection of certain cortical areas from the processing of extero- or proprioceptive signals and their transition to spiking and slow wave electrical activity, which is typical for sleep, while awake. The authors believe that it is the second phenomenon that can be called real local sleep. The appearance of local cortical sleep is inseparably linked with the occurrence of local wakefulness. It can be expected that the occurrence of local sleep will have detrimental consequences for behavior in urgent and complicated situations, while local wakefulness can adversely affect the visceral health of the body. A possible way of early detection of the local sleep development is proposed. In conclusion, some methodological problems on the way of electrophysiological studies of the local aspects of sleep and wakefulness are considered.