Latent inhibition, visual pop-out and schizotypy: is disruption of latent inhibition due to enhanced stimulus salience?

The disruption of latent inhibition (i.e. conditioning rate to a preexposed (PE) stimulus elevated to the level of a non-preexposed (NPE) stimulus) within the schizophrenia continuum has often been attributed to increased attentional distractibility by irrelevant stimuli. It has not been established, however, whether such a putative distractibility is due to a tendency to treat any stimulus as salient on the basis of physical characteristics (enhanced stimulus salience). In order to test this possibility, extreme schizotypy scorers were selected from a larger sample of undergraduate students to take part in a two-experimental investigation. In Experiment 1, latent inhibition, as assessed in a visual search paradigm, was disrupted in high-schizotypy scorers, but was intact for low-schizotypy scorers replicating past findings. In Experiment 2, no evidence for an enhanced stimulus salience, as assessed in a visual pop-out task, was found for high-schizotypy scorers. Accuracy rate for both high- and low-schizotypy scorers followed the hierarchically differentiated pattern of the stimulus salience level, failing to support the hypothesis that high-schizotypy scorers tend to treat any stimulus as salient on the basis of physical characteristics. The obtained results suggest that the disruption of latent inhibition in high-schizotypy scorers is not associated with a tendency to experience any event (i.e. both PE and NPE stimuli) as perceptually salient.