Does the ability to sustain attention underlie symptom severity in schizophrenia?

An association between deficits in executive control, particularly inhibitory control, and more severe negative and disorganised symptoms of schizophrenia has been widely reported. The importance of more basic aspects of attention, often referred to as 'vigilant' or 'sustained' attention, to this relationship remains unclear. This study examined the contribution of sustained attention to symptom severity using the Sustained Attention to Response Task (SART) in 69 patients with schizophrenia. We found that negative and disorganised symptom severity scores were correlated with sustained attention, working memory, and psychomotor speed. The ability to sustain attention significantly predicted variance in negative symptom severity but not disorganised symptoms, which were instead predicted by working memory performance. These data suggest that this component of attention at least partly explains variance in negative symptoms.

Are relational style and neuropsychological performance predictors of social attributions in chronic schizophrenia?

Attributional style is defined as the pervasive tendency to explain the cause of social actions in terms of oneself, or others, or the context of the event. While the clinical correlates of this aspect of social cognition have been widely researched, its links with relationship style and neuropsychological performance, although hypothesised, have received less attention. This study investigated whether attributional style is predicted by variance in either relationship style or neuropsychological performance in schizophrenia. We assessed attributional style (using the Internal, Personal and Situational Attributions Questionnaire [IPSAQ]), relationship style (using Bartholomew and Horowitz's Relationship Questionnaire), and neuropsychological function (using the Wechsler Abbreviated Scale of Intelligence, the Wechsler Memory Test, and the Cambridge Automated Test Battery) in 73 stabilised outpatients with chronic schizophrenia and 78 controls matched for age and gender. 'Externalising bias' (attributing positive rather than negative events to oneself) was predicted by verbal ability in both patients and controls. 'Personalising bias' (attributing negative events to others rather than to situational factors) was predicted by higher secure relationship style ratings, but only in the patient group. This study highlights the importance of relationship style and neuropsychological performance for different aspects of attributional style in schizophrenia.

Mental state decoding v. mental state reasoning as a mediator between cognitive and social function in psychosis.

Theory of mind deficits in schizophrenia have been parsed into mental state reasoning and mental state decoding components. We report that mental state decoding as measured by the 'Eyes task' better predicted social function than mental state reasoning as measured by the 'Hinting task' in 73 out-patients with chronic schizophrenia. Mental state decoding task performance also partly mediated the influence of basic neuropsychological performance on social function. We discuss these findings in terms of the accumulating evidence that mental state decoding has particular relevance for understanding deficits in social function in schizophrenia.