The effect of stimulus specificity and number of pre-exposures on latent inhibition in an instrumental trials-to-criterion task

Abstract

Latent inhibition, the retardation of Pavlovian conditioning after pre-exposure to the to-be-conditioned stimulus, has been suggested as a tool for assessing attentional malfunctioning in schizophrenia. The present research investigated whether retarded learning as observed in an instrumental trials-to-criterion task displays two characteristics of latent inhibition: stimulus specificity and increased retardation with increased pre-exposure. Retarded learning was evident after pre-exposure to the to-be-conditioned stimulus and to an experimentally irrelevant stimulus. Increased numbers of pre-exposure trials did not seem to enhance the retardation of learning in pre-exposed participants, but enhanced learning in controls. The present results suggest that retarded learning in the trials-to-criterion task may reflect a process that is different from latent inhibition.