QUANTITATIVE ELECTROENCEPHALOGRAM OF POSTERIOR CORTICAL AREAS OF FLUENT AND STUTTERING PARTICIPANTS DURING READING WITH NORMAL AND ALTERED AUDITORY-FEEDBACK

In the left and right hemisphere, posterior quantitative electroenceph alogram Beta band activity (13.5-25.5 Hz) of seven adult participants who stutter and seven age-matched normal controls was obtained while s ubjects read text under three experimental conditions of normal audito ry feedback, delayed auditory feedback, and frequency-altered feedback . Data were obtained from surface electrodes affixed to the scalp usin g a commercial electrode cap. Electroencephalogram activity was amplif ied, band-pass analog-filtered, and then digitized. During nonaltered auditory feedback, stuttering participants displayed Beta band hyperre activity, with the right temporal-parietal lobe region showing the gre atest activity. Under conditions of delayed auditory feedback and freq uency-altered auditory feedback, the stuttering participants dis playe d a decrease in stuttering behavior accompanied by a strong reduction in Beta activity for the posterior-temporal-parietal electrode sites, and the left hemisphere posterior sites evidenced a larger area of rea ctivity. Such findings suggest than an alteration in the electrical fi elds of the cortex occurred in the stuttering participants under both conditions, possibly reflecting changes in neurogenerator status or cu rrent dipole activity. Further, one could propose that stuttering refl ects an anomaly of the sensory-linguistic motor integration wherein ea ch hemisphere generates competing linguistic messages at hyperreactive amplitudes.