Detection of EEG abnormalities with feedback stimulation

Ten-year stability of EEG biofeedback results for a hyperactive boy who failed fourth grade perceptually impaired class

Ten years ago, the first successful application of a clinical, private-practice based, EEG 14-Hz biofeedback training regimen for the treatment of learning disorders was performed by the author. After the 10-year-old boy, with presenting symptomatology including a developmental reading disorder, hyperactivity, and an educational classification of perceptually impaired, continued symptom free for a period of two years, his case was submitted for publication. Ten years after his termination from successful treatment, his ongoingly normal social and academic functioning is noted and his EEG brainwave signature examined and compared with a population of 24 "used-to-be" learning disabled, one-half of which had a pretreatment state including the educational classification of perceptually impaired. This 10-year follow-up confirms the long-term stability of the results of this EEG 14-Hz biofeedback regimen. Current findings on recent medical research identifying a major cerebral locus of dysfunction for hyperkinesis and how it supports the electrode placements of this clinical office setting regimen is also discussed.

Feedback control and quantification of the response of EEG alpha to visual stimulation

The response of the posterior EEG alpha thythms to visual stimulation is so variable that it is difficult to obtain reliable on-line measurement of it. Feedback between the EEG alpha and the visual stimulus (1) reduces random variation in the response and (2) facilitates on-line quantification. With feedback EEG, the response to visual stimulation is measured as a series of time durations of alpha and of no-alpha intervals in the EEG. This time series occurs in two stages: an initial disturbance followed by a recovery. The quantification of the series of time durations is achieved by fitting curves to the series of alpha time intervals and of no-alpha time intervals. These functions, computed in each trial of 30 stimulations, are an objective, quantitative definition of EEG response. The utility of the method was demonstrated by testing it with reference to well-known effects. Habituation to a repeated stimulus, dishabituation, habituation to a class of stimuli, dishabituation by changing the class of stimuli, and differences among brain-lesioned, psychiatric patients and normals were shown with a detailed quantification. It was concluded that biofeedback is the method of choice for quantitative research on the EEG component of the human orienting response.

EEG and behavioral changes in a hyperkinetic child concurrent with training of the sensorimotor rhythm (SMR): a preliminary report

Reduced seizure incidence coupled with voluntary motor inhibition accompanied conditioned increases in the sensorimotor rhythm (SMR), a 12- 14 Hz rhythm appearing over rolandic cortex. Although SMR biofeedback training has been successfully applied to various forms of epilepsy in humans, its potential use in decreasing hyperactivity has been limited to a few cases in which a seizure history was also a significant feature. The present study represents a first attempt to explore the technique's applicability to the problem of hyperkinesis independent of the epilepsy issue. The results of several months of EEG biofeedback training in a hyperkinetic child tend to corroborate and extend previous findings. Feedback presentations for SMR were contingent on the production of 12- 14-Hz activity in the absence of 4- 7-Hz slow-wave activity. A substantial increase in SMR motor inhibition, as gauged by laboratory measures of muscular tone (chin EMG) and by a global behavioral assessment in the classroom. Opposite trends in motor inhibition occurred when the training procedure was reversed and feedback presentations were contingent on the production of 4- 7 Hz in the absence of 12- 14-Hz activity. Although the preliminary nature of these results is stressed, the subject population has recently been increased to establish the validity and generality of the findings and will include the use of SMR biofeedback training after medication has been withdrawn.