Executive attention deficits in schizophrenia: Putative mandatory and differential cognitive pathology domains in medicated schizophrenia patients

Executive attention (EA) is a core-construct of working memory (WM) capacity. EA performance is directly related to dorsolateral prefrontal cortex (DLPFC) activation, a neural mechanism that is dysfunctional in schizophrenia. We examined the differences in particular types of EA failure in schizophrenia patients and healthy controls. We evaluated executive attention in 60 medicated schizophrenia patients and 60 matched healthy individuals. We used a standard WM task, a verbal n-Back task, to measure executive attention (WM accuracy). Our standard-version WM task (control block, 10 min long) was designed to examine baseline executive attention function and was followed by one out of three different experimental blocks (revised n-Back tasks). Baseline executive attention performance was significantly related to psychosis severity and functional capacity in the psychiatric group. In both healthy and psychiatric groups, experimental-block conditions revealed that domain-general recall had a differential effect on WM scores, and was related to the patient's clinical condition. Only in the psychiatric group domain-specific recall impairments were mandatory, most severe, and independent of baseline WM scores. The results revealed the importance of domain-general recall WM scores in the evaluation of executive attention deficits in patients and controls. Disruption in domain-specific recall may represent a specifier of cognitive impairment in schizophrenia spectrum disorders.