Are high-schizotypal normal participants distractible or limited in attentional resources? A study of latent inhibition as a function of masking task load and schizotypy level.

Two experiments with normal participants examined the effects of masking and masking task load on latent inhibition (LI, poorer learning for a previously exposed irrelevant stimulus than for a novel stimulus) as a function of level of schizotypality. In Experiment 1, a masking task was needed to produce LI. In Experiment 2, with low load, LI was present in low- but not high-schizotypal participants. In high load, LI was abolished in low-schizotypal participants, but only approached significance in high-schizotypal participants. The data support a distraction- rather than a resource-limitation model of attentional dysfunction in high-schizotypal normal participants. In addition, the data indicate that obtaining LI requires that some attention be initially allocated to the preexposed stimulus and then reduced. Implications of the model for understanding attentional dysfunction in schizophrenia are discussed.