Electrocortical reactions associated with conditioned flexion reflexes

Abstract

Cats with permanently implanted cortical electrodes were drugged with bulbocapnine and the EEG recorded continuously during the formation of flexion conditioned reflexes (CR). The drug has no readily detectable effect on rate of conditioning and usually produces such slow EEG patterns that electrocortical arousal reactions are well demarcated. Arousal reactions to a tonal conditional stimulus (CS) given alone soon cease to occur, but become more frequent as the CS is paired with an unavoidable shock to the leg 25-50 times a day over several days. In all cases the EEG reactions attain a high level of consistency before the first respiratory or flexion CRs appear, almost invariably accompany them, and can survive for some time after these somatic CRs are fully extinguished. There is a tendency, however, for the EEG arousal response to diminish with overtraining despite continuation of somatic CRs and shock reinforcement, and in certain instances somatic CRs can occur during relatively slow electrocortical activity. There was no evidence that the somatic CRs correlated with any localization of electrocortical reactions or alterations of cortical evoked potentials.