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BIOFEEDBACK INSTRUMENTATION
A late model Autogenic Systems 120 EEG analyzer was used for the study. The in is a single channel operational amplifier which signal conditions with period to period analysis to compute real-time dominant frequency and amplitude into analog output signals ranging between 0 and 10 volts DC for conversion to audio feedback signals and further data recording. The frequency output and "raw" EEG were recorded on Channels I and 2, respectively, of a Grass Instrument Model 79D polygraph. The analyzer and polygraph were interfaced using two Grass 7PO3 adaptor panels. One channel of EEG was used to independently record data on the polygraph's third channel using a Grass Model 7PB3 wide-band AC amplifier.
Beckman standard-size Ag/Ag C1 electrodes with adhesive discs and Parker Signa electrode gel were applied after cleaning the scalp with alcohol and abrading with Hewlett Packard Redux electrode paste. Electrode attachment was tested using a J&J Limited electromyograph (EMG) electrode test circuit accepting a resistance of < 5.000 ohms. Ground electrode was placed on the contralateral mastoid process. Electrode placements were anterior temporal (F7 or F8) and posterior temporal (T3 or T6). A medical neurologist selected the more abnormal hemisphere; if the clinical EEG's were not focal, the right hemisphere was recorded (F8 and T6). Each recording electrode yoked into respective grids of the Grass and A.S.I. amplifiers for simultaneous comparison recording of each instrument.
Bilateral anterior temporalis surface EMG was recorded with the electrodes and procedures described above. Placement was determined by palpation of the muscle under contraction. 'Me muscle action potentials were amplified and signal conditioned with a J&J Limited Model 55 EMG using a bandpass of 100 to 200 Hz and displaying RMS amplitude values. The full wave rectified surface EMG output was fed into a Grass adaptor panel and recorded on Channel 4 of the polygraph with a driver-amplifier setting 1/2 amplitude high frequency at 0.5 Hz.
') Includes temporal lobe epilepsy. psychomotor epilepsy | 
