Premium
Spectral Evaluation of the Electroencephalogram: Power and Variability in Chronic Schizophrenics and Control Subjects
Author(s) -
Lifshitz Kenneth,
Gradijan Jack
Publication year - 1974
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.1974.tb00576.x
Subject(s) - electroencephalography , psychology , audiology , discriminator , arousal , coefficient of variation , artifact (error) , absolute power , psychosis , spectral density , cardiology , statistics , psychiatry , neuroscience , mathematics , medicine , physics , politics , political science , law , detector , optics
Selected EEG parameters were evaluated for their ability to discriminate between a group of 30 chronic schizophrenic and 30 control S s. For each S 150 random EEG segments were collected. The results confirmed that the coefficient of variation of the absolute EEG potential recorded from the occiput is significantly (φ <.03) smaller in schizophrenics than in controls. The power density spectrum was calculated for each EEG segment. β power was significantly higher in patients, markedly so in the β 2 band (34–54 Hz). The possibility of muscle contamination was considered. Coefficients of variation were calculated for the power in EEG frequency bands for each S . The most significant discriminator between schizophrenics and controls, considered to be artifact free, was the coefficient of variation of β 1 (18–32 Hz) recorded from an anterior‐posterior electrode pair at the vertex ( p <.0005). Included in the evaluations were: ordering of the EEG segments by delta band power, as an index of arousal; subject age; exposure to medication; and severity of illness.