Relation of Electroencephalographic Delta Activity to Behavioral Response in Electroshock

Recent theories of electroshock therapy¹⁻³have emphasized the role of neurophysiologic changes as the basis for the therapeutic action of electroshock. Consistent with these theories, we have observed a relation between changes in certain measures of brain function and behavioral response. We have noted that evaluations of clinical improvement following electroshock are related to changes in orientation and confabulation after intravenous amobarbital,⁴learning and recall,⁵and syntactical aspects of language.⁶ In view of these observations, it could be expected that electroencephalographic studies would show a similar relationship. Numerous observers have reported consistent changes in the electroencephalogram after electrically induced convulsions. There is diffuse slowing with increased voltage and dysrhythmic activity.⁷⁻¹²Fast activity decreases, both in voltage and in percent time,¹³and in patients who are intensively treated there is a slowing of persistent alpha frequencies.¹⁴The degree, duration, and extent of delta activity are