RELATING LEFT EAR ADVANTAGE TO COGNITIVE PERFORMANCE IN PATIENTS WITH BRIEF PSYCHOTIC DISORDER OR SCHIZOPHRENIA: A DICHOTIC LISTENING STUDY

Abstract

Left ear advantage (LEA), the ability to report more correct syllables in the forced-left condition of the dichotic listening task, is reported to involve executive control. This study therefore sought to uncover the relationship between LEA and the cognitive dysfunction seen across psychosis spectrum disorders, specifically, that reduced LEA is related to poorer performance on Verbal Memory, Digit Sequencing (working memory) and Tower of London (executive functions) tasks. Patients from IMH diagnosed with Brief Psychotic Disorder or Schizophrenia were recruited to complete a dichotic listening task and a cognitive test (Brief Assessment of Cognition in Schizophrenia). Scores on the forced-left condition of the dichotic listening task were correlated with scores of the cognitive subtests. Findings revealed that poorer performance in the forced-left condition were significantly related to poorer performance on the Verbal Memory and Digit Sequencing (working memory) subtests. No significant correlation exists between performance in the forced-left condition and Tower of London (executive functions) subtest. Further analyses revealed the relationship to be found in patients with psychosis spectrum disorders but not in controls. This finding suggests that certain aspects of psychosis could be mediating/moderating the relationship.