Intracortical auditory evoked potentials during classical aversive conditioning in cats.

Auditory evoked potentials (EPs) were recorded simultaneously from six different depths of the auditory cortex of freely moving cats. In a classical aversive learning paradigm the change of the pitch of regularly given acoustic stimuli served as warning signal. With conditioning the amplitude of a middle latency negative component increased and its latency decreased. Based on laminar analysis of EP profiles we propose that the observed EP changes were generated within the upper cortical layers and reflected a temporary aurousal reaction induced by the signal as a result of discrimination learning. For the description of this effect the term "learned aversive arousal" is suggested.