Latent inhibition and recall/recognition of irrelevant stimuli as a function of pre‐exposure duration in high and low psychotic‐prone normal subjects

Abstract

Learning to ignore non‐relevant stimuli (coloured geometric shapes) was evaluated in high and low psychotic‐prone normal subjects in two experiments. In the first, subjects were tested in a latent inhibition paradigm in a 2 times 2 × 3 factorial design (high vs. low psychotic proneness, as measured by MMPI subscales; pre‐exposure of the stimuli such that they were non‐relevant before the test but relevant in the test vs. absence of such pre‐exposure; three levels of pre‐exposure duration: 3‐, 6‐and 15‐min). Low psychotic‐prone subjects showed the latent inhibition effect (poorer learning as a result of pre‐exposure to the non‐relevant stimuli as compared to no pre‐exposure) at 6‐ and 15‐min durations, but not at 3‐min. High psychotic‐prone subjects failed to show latent inhibition at 3‐ and 6‐min durations, but did show the effect at 15‐min. The second experiment employed a 2 times 3 design (high vs. low psychotic proneness; three levels of pre‐exposure duration of the same stimuli used in Expt 1). High psychotic‐prone normal subjects recalled and recognized more previously non‐relevant stimuli than low psychotic‐prone subjects, particularly after 6‐min pre‐exposure to those stimuli. The data of the two experiments suggest that the attenuation of latent inhibition in high psychotic‐prone subjects as compared to low psychotic‐prone subjects is a result of the increased attention to non‐relevant information.