Attention, Discrimination, and Arousal During Sleep

THAT THE human brain during sleep can perform tasks learned during the waking hours is indicated by the ability of man to discriminate various types of sounds during sleep. This ability of the sleeper to pay attention to the sounds about him, and select one sound from another requires discriminatory mechanisms of as great a magnitude as when the same individual is in the awake state. Thus, for any sensory stimulus which occurs during sleep, there exists the following sequence of events: reception of stimulus by the appropriate sensory organ with Pathways to the reticular formation and the cerebral cortex, discriminative analysis of the stimulus for importance and content by the cerebral cortex, and corticofugal impulses back to the reticular formation, which in turn may or may not evoke arousal. The arousal signs may be behavioral, autonomic, or electroencephalographic. Previous investigation by the authors using EEG techniques, showed that a