The effects of attention on language laterality in schizophrenia

Language lateralization is reduced in schizophrenia patients relative to healthy individuals. It remains unclear whether these findings are moderated by the impaired attentional processes seen in the disorder. This study investigated whether patients increase their right ear advantage with the aid of a tone cue to systematically control for the effects of decreased alertness. Eighteen right-handed patients with schizophrenia or schizoaffective disorder and 18 right-handed healthy controls matched on age, gender, and parental education, completed a traditional dichotic listening task and a second dichotic task in which a binaural tone was presented prior to each stimulus pair. It was hypothesized that patients would demonstrate a stronger REA in the tone condition, and would benefit more from the tone than controls. Results revealed similar lateralization between groups in both conditions, and thus did not support the hypotheses. Nonetheless, results also suggested that the tone decreased attentional resource demands during dichotic monitoring.