Performance on the visual search analog of latent inhibition is modulated by an interaction between schizotypy and gender

Two experiments examined the visual search analog of latent inhibition (LI) and the novel popout (NPO) effect in healthy humans. In Experiments 1 (n = 48) and 2 (n = 180). subjects judged the positions (left or right side of a computer screen) of a unique target amongst a field of homogeneous distra ctors. In both experiments, there was a strong LI effect, as indicated by l onger response times (RT) to those displays in which the target was previou sly a distractor and the distractors were previously the target, as compare d with displays in which the target was novel and the distractors were prev iously the target. NPO, faster RT to a display in which the target was nove l on a background of familiar distractors than to a display in which both t arget and distractors were novel, was not obtained. In Experiment 1, LI mag nitude was not affected by gender. In Experiment 2, LI magnitude was larger for low schizotypal females than for high schizotypal females, a result no t obtained for males. This pattern is similar to one reported for medicated schizophrenic out-patients (Lubow, R.E., Kaplan, O., Abramovich, P., Rudni ck, R., Laor, N., 2000. Visual search in schizophrenics: latent inhibition and novel popout effects. Schizophr. Res., in press). Together, these data suggest that the LI deficits found in high schizotypal healthy subjects and in schizophrenic patients represent a dysfunction that is characterized by an inability to reduce attention allocated to irrelevant stimuli, and that this may serve as a trait marker for some subtypes of schizophrenia, parti cularly those associated with female gender. (C) 2001 Elsevier Science B.V. All rights reserved.