J Neuropsychiatry Clin Neurosci 1991; 3:307-314
Copyright © 1991 by American Neuropsychiatric Association
Average reference EEG lateralization in schizophrenic patients
EL Merrin and TC Floyd
Psychiatry Service, VA Medical Center, San Francisco, CA 94121.
The authors transformed 9 channels of electroencephalogram (EEG) to 10
channels of average reference data and compared EEG asymmetry between
medication-free (for 2 weeks) schizophrenic male patients (n = 14), male
patients with affective disorder (n = 9), and normal males (n = 13).
Multivariate analyses failed to find lateralized differences between groups
in resting and task EEG. Neuroleptic treatment (n = 11) was associated with
asymmetrical changes in beta power rather than in alpha and theta, as
previously reported. There were no relationships between clinical ratings
(based on the Brief Psychiatric Rating Scale and subscales) and alpha
asymmetry. The authors discuss conflicts with previous findings and the
advantages of minimizing reference bias when studying EEG topography.
