Electroencephallograms and Conditioned Reflexes

Abstract

Conditioned galvanic skin-reflexes were established in man with an electric bell as a conditioned stimulus and with a brief faradic current as an unconditioned stimulus.
1. Upon the conditioned stimulus there appeared characteristic changes in eeg. (Ep.), which were followed by a galvanic skin response. When conditioning was not complete, only an Ep. appeared without being followed by any skin-response.
2. The skin-response ceased to appear, but the Ep. did not disappear completely by extinction procedure (repetition of conditioned stimuli). These facts suggest that the Ep. is a precursor for the external response.
3. When the interval between the beginning of the conditioned stimulus and the administration of the unconditioned stimulus was long the appearance of the Ep. as well as that of the skin-response were delayed (delayed conditioned reflex). The potential pattern under this condi-tion is discontinuous and of long duration, and this characteristic feature can be explained by the assumption that the delayed conditioned response appears after a long rivalry between excitation and inhibition.
4. The long lasting Ep. in the delayed conditioned reflex came im-mediately to an end when the unconditioned stimulus was delivered.