ABSTRACT
The effects of audio-visual stimulation at the dominant alpha frequency and twice dominant alpha frequency on the EEG were investigated. An eyes-closed baseline EEG determined each subject's dominant alpha frequency. Subjects were stimulated at their dominant alpha frequency and at twice dominant alpha frequency for 20 min on two occasions. A 30-min post-session eyes-closed EEG was recorded after each session. Power data were analyzed for 19 locations in six bandpasses using repeated-measures ANOVAs and appropriate post-hoc tests. Alpha stimulation significantly increased power over baseline levels in the delta 1, delta 2, theta, beta 1 and beta 2, with significant effects remaining 30 min later in beta 1. Twice alpha stimulation significantly increased theta, beta 1 and beta 2 power over baseline levels, with significant effects remaining 30 min later in theta, alpha, beta 1 and beta 2.
Subject(s)
Alpha Rhythm , Cerebral Cortex/physiology , Electroencephalography , Acoustic Stimulation , Adult , Beta Rhythm , Female , Humans , Male , Ocular Physiological Phenomena , Photic StimulationABSTRACT
The psychophysiologic and behavioral effects of methylphenidate were assessed in boys with attention deficit hyperactivity disorder between the ages of 9 and 11 years. The effects of methylphenidate on the EEG during baseline and cognitive tasks were evaluated using spectral analysis. Both subjective (rating scales) and objective (continuous performance) measures were administered and analyzed in conjunction with the electrophysiologic data. Although methylphenidate induced regional changes in the EEG under certain task-specific conditions, it had no global effects. Behavioral and performance measures improved with methylphenidate.
