Validation of a right hemisphere vigilance system as measured by principalcomponent and factor analyzed quantitative electroencephalogram

Arruda and colleagues [Arruda, J.E., Weller, M.D., Valentine, D.A. et al., 1996. A guide for applying principal-component analysis and confirmatory fa ctor analysis to qEEG data. Int. J. Psychophysiol. 23, 63-81.] recently des cribed seven neurophysiological measures that were previously derived and c onfirmed using factor analytic procedures and the quantitative electroencep halogram (EEG) sampled from 208 normal controls during an auditory continuo us performance test (CPT). The purpose of the present investigation was to further test the validity of these empirically derived measures by examinin g each measure's relationship with CPT-related declines in performance. Par ticipants were 48 right-handed men (n = 13) and women (n = 35) who reported being free of any neurological condition, birthing complications, or loss of consciousness greater than 2 min. After completing an eyes-closed restin g condition, participants performed a 23-min CPT while both quantitative EE G and behavioral performance were measured at 45, 405, 765 and 1125 s into the CPT. Bipolar recordings were gathered using the International 10-20 sys tem, from eight sites: frontal, fronto-temporal, temporal and temporal-occi pital. Multivariate and follow-up univariate tests suggest the existence of a neurophysiological system located within the right temporal region that appears essential for the maintenance of a sustained attentional state. If confirmed, the further quantification of this neurocognitive system may pro ve useful as part of a clinical diagnostic workup. (C) 1999 Elsevier Scienc e B.V. All rights reserved.