Metaphor processing in high and low schizotypal individuals.

Two hypotheses were considered regarding the relationship between positive schizotypy and metaphor processing. On the basis of continuity between schizophrenia and schizotypy, high schizotypal individuals would be expected to be impaired at metaphor processing. However, given the right hemisphere processing bias that has been associated with positive schizotypy, they would be expected to be superior at metaphor processing. A story completion task in which participants judged the appropriateness of literal and metaphoric statements was administered to 30 high and 29 low schizotypal individuals. Contrary to both hypotheses, groups did not differ in their ability to discriminate between appropriate and inappropriate statements, whether literal or metaphoric. However, the high schizotypal group demonstrated a less conservative response bias; they were more likely than the low schizotypal group to identify a statement as appropriate, whether it was or was not. Implications of these results for our understanding of language processing in schizophrenia and schizotypy are discussed.

Semantic ambiguity resolution in positive schizotypy: a right hemisphere interpretation.

Positive schizotypal traits have been associated with right hemisphere activation. Previous research has indicated that the left and right hemispheres differ in their processing of semantic ambiguity; specifically, given sufficient time, the left hemisphere primes dominant meanings and inhibits subordinate meanings, and the right hemisphere primes both dominant and subordinate meanings. The authors examined whether individuals who differed in positive schizotypy demonstrated different patterns of priming on a semantic ambiguity task, reflective of differences in hemispheric activation. Individuals low in schizotypy demonstrated the expected pattern of priming the dominant meaning while inhibiting the subordinate meaning. Individuals high in schizotypy demonstrated similar priming of the dominant meaning but no inhibition of the subordinate meaning. The role of this failure of inhibition in the generation of schizotypal thought is discussed.

The role of intellectual openness in the relationship between hand preference and positive schizotypy.

Recently it has been suggested that the relationship between positive schizotypy and mixed handedness is limited to questionnaire measures, and thus reflects some aspect of questionnaire-taking behaviour as opposed to some aspect of atypical brain organisation. The current study set out to explore this possibility. Undergraduate psychology students completed the Magical Ideation Scale, the Waterloo Handedness Questionnaire-Revised, a manual dot-filling task, and an inventory measuring the personality trait of intellectual openness. On the questionnaire measure, magical ideation was related to mixed handedness on unskilled but not skilled hand preference; however, this relationship was partially mediated by intellectual openness. Magical ideation was not related to the behavioural measure of handedness. These findings suggest that responses on handedness questionnaires partially reflect personality variables, and such effects should be considered in future research on the nature of the relationship between handedness and schizotypy.