Conditioned suppression following CS preexposure

The present experiment evaluated both unconditioned and conditioned suppression in response to a preexposed CS in order to determine the extent to which these two processes contribute to the observation of “latent inhibition” in the conditioned suppression situation. Independent groups of rats received 0, 2, 5, 10, 25, or 50 CS preexposures prior to conditioned suppression training. Ss receiving more than 2 CS preexposures did not evidence unconditioned suppression in response to the CS, but nevertheless differed in acquisition of the conditioned suppression response, with more extensive preexposure associated with less conditioned suppression.