Distractor cueing effects on choice reaction time and their relationship with schizotypal personality.

Abstract

Although usually displaying increased distractibility, schizophrenic patients sometimes show a reduced influence of distractors during selective attention tasks. This study explored whether reduced distractor processing effects can also occur in healthy individuals with high levels of schizotypal personality traits. In all, 36 healthy volunteers completed schizotypal personality scales and a choice reaction time (RT) task in which they responded to the central letter of triads (XMX, YCY), ignoring the flanking distractors. RT increases on low-probability probe trials (YMY, XCX) measured distractor processing ('the distractor cueing effect'). Correlations between schizotypy scores and distractor cueing were evaluated. Healthy participants with high positive schizotypy scores (i.e. those reporting more hallucination-like experiences and delusion-like beliefs) showed smaller distractor cueing effects than those with lower scores. This association was independent of the influence of other schizotypal personality traits (disorganized, negative or asocial schizotypy) and was significant only for right-hand responses. These findings closely parallel the previously reported reduced distractor cueing effect, for right-hand responses, among acute-phase schizophrenic patients. Finding reduced distractor cueing effects in healthy participants with high levels of positive schizotypy increases confidence that reduced distractor cueing is a specific feature, rather than a non-specific consequence, of acute-phase schizophrenia.