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This study was a preliminary evaluation of biofeedback training of human subjects to control high-frequency EEG responses in the 35- to 45-Hz (40-Hz) and 21- to 31-Hz ranges. A total of 22 adult males divided into three groups were successfully trained for increases or suppression of 40-Hz EEG, or increases of 21- to 31-Hz EEG. Dissociation of rates of 40-Hz EEG recorded from scalp leads and 40-Hz EMG responses from prominent muscle contaminators, and partial dissociation of 40-Hz and 21- to 31-Hz EEG responses were noted. After biofeedback training, 8 subjects demonstrated increase and suppression of 40-Hz EEG without feedback. No consistent descriptors of subjective experiences accompanying EEG changes were reported by subjects in any of the groups. The study suggests the utility of biofeedback procedures in research on high-frequency EEG activity.

This study used an electrophysiological measurement operation to investigate lateralized processing deficits associated with academic learning-disability subtypes. Fast frequency EEG activity in the 36-44 hertz (Hz) band was recorded from reading-disabled (RLD), arithmetic-disabled (ALD), and nondisabled control children engaged in verbal and nonverbal cognitive tasks. The control group, but neither LD group, exhibited a task-dependent shift in lateralization of 40 Hz EEG; the RLD subjects generated proportionately less left-hemisphere 40 Hz activity than control or ALD subjects during the verbal task; and the ALD subjects generated proportionately less right-hemisphere activity than control or RLD subjects during the nonverbal task. These results indicate that lateralized processing deficits are associated with different types of disabilities, and provide external validation of learning-disability classifications based on academic performance patterns.

Task dependent lateralization of the 40 Hz EEG rhythm and its relationship to 40 Hz EMG activity were investigated in 24 right‐handed subjects. Each subject was administered four tests: verbal analogies, mathematical problems, facial discrimination, and geometric figure rotation. Bilateral EEG and EMG activity were recorded during each of the tests. Lateralization of the 40 Hz EEG rhythm was found during three of the four tasks. No comparable lateralization of 40 Hz EMG activity was found. Results are discussed in terms of 40 Hz EEG as resulting from a focused state of cortical arousal, and of 40 Hz EEG as differentiable from 40 Hz EMG.