Magical ideation and right-sided hemispatial inattention on a spatial working memory task: influences of sex and handedness.

Abstract

A correlation between magical ideation scores and the size of relative right-sided hemispatial inattention was previously reported for healthy right-handed men performing a tactile line-bisection task. To re-investigate this relation, a computerized version of Corsi's Block-Tapping Test was used to test working memory. In this version, different numbers of cubes are similtaneously displayed on a screen, and after the cubes disappear the subject is asked to designate the cubes' locations on a grid as quickly as possible. 98 healtly medical students were divided into four groups on the basis of their handedness and sex in the following way: right-handed men, right-handed women, nonright-handed men, and nonright-handed women. Each subject performed the test once with the right hand and once with the left hand. Accuracy and Neglect scores were computed for the two hemispaces separately. Also, all subjects filled in the Magical Ideation Scale which asks for hallucination-like experiences and delusion-like beliefs. In all groups a significant right-sided inattention was found when subjects performed with the right hand. Magical Ideation scores were significantly correlated with Neglect in the right hemispace for the right-handed women when the right hand was used. For the nonright-handed men, when the right hand was used, a significant negative correlation between Magical Ideation scores and Neglect scores in the left hemispace was found. Our findings support the previous study in some aspects and suggest that the correlation between hemispatial inattention and proneness to schizotypy in normal subjects is restricted to right-hand performance.