title: Alpha EEG coherence in different brain states: an electrophysiological index of the arousal level in human subjects.
abstract: The functional relationships between the brain areas supposedly involved in the generation of the alpha activity were quantified by means of INTRA- and INTER-hemispheric coherences during different arousal states (relaxed wakefulness, drowsiness at sleep onset, and rapid eye movement sleep) where such an activity can be clearly detectable in the human EEG. A significant decrease in the fronto-occipital as well as in the inter-frontal coherence values in the alpha range was observed with the falling of the vigilance level, which suggests that the brain mechanisms underlying these coherences are state dependent. Making fronto-frontal coherence values in the alpha frequency band useful indexes to discern between brain functional states characterized by a different arousal level.
authors.affiliation: Laboratorio de Sueño, Area de Psicofisiología Cognitiva, Seville, Spain. suesevilla@interbook.net
authors.forename: J L
authors.initials: JL
authors.lastname: Cantero
authors.forename: M
authors.initials: M
authors.lastname: Atienza
authors.forename: R M
authors.initials: RM
authors.lastname: Salas
authors.forename: C M
authors.initials: CM
authors.lastname: Gómez
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001143:Arousal / Q000502:physiology*; D005583:Fourier Analysis; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D009778:Occipital Lobe / Q000502:physiology; D012894:Sleep Stages / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology*