Executive attention deficits in schizophrenia: Putative mandatory and differential cognitive pathology domains in medicated schizophrenia patients Oded Meiron a,b,n , Haggai Hermesh b , Nachum Katz b , Abraham Weizman a,b a Tel Aviv University, Tel Aviv, Israel b Geha Mental Health Center, Petach Tikva, Israel article info Article history: Received 23 November 2011 Received in revised form 27 September 2012 Accepted 28 September 2012 Keywords: Working memory n-Back task Neurocognition abstract 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. & 2012 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Working memory (WM) impairments are closely associated with schizophrenia (Keefe et al., 2004; Tan et al., 2006; Potkin et al., 2009). Working memory, the ability to maintain and utilize information in short-term memory (Baddeley and Hitch, 1974; Baddeley, 1986), is central to everyday functioning, and contri- butes significantly to other areas of cognition (Honey and Fletcher, 2006). Executive attention (Kane and Engle, 2002), the core mechanism of WM capacity, is the capability to regulate goals, which enables coherent and contextually appropriate behavior in interference-rich conditions (Conway et al., 2005). Thus, executive attention is the ‘‘core’’ feature of WM capacity because it is mainly involved in maintaining access to stimulus representations and goals in interference-rich contexts (Kane and Engle, 2002). Schizophrenia patients’ primary domains of cognitive impair- ment, including executive function, working memory, and verbal memory (Keefe et al., 2004), may share a common prefrontal cortex mechanism dysfunction resulting from inefficient dorso- lateral prefrontal cortex (DLPFC) activity during WM maintenance (Potkin et al., 2009). Furthermore, the DLPFC functions as a rule- based response-selection neural network (Bunge, 2004) that actively maintains access to a temporal model of the environment to produce an appropriate response to a target stimulus in a specific goal-driven context (Kane and Engle, 2002). Therefore, since active WM maintenance is mediated by executive attention, the development of a reliable cognitive test of illness-related impairments that measures executive attention deficits in schizo- phrenia patients may serve as a tool in the development of interventions aimed to improve cognitive function and quality of life in schizophrenia patients (Ventura et al., 2010; Shamsi et al., 2010). However, it is critical to discriminate between the different components of this memory impairment in order to localize a pathology resulting from the dysfunction of a particular neurocognitive mechanism (Jansma et al., 2004). Thus, we believe that the detection of mandatory (e.g., across all schizophrenia patients), as well as differential (e.g., within a subgroup of Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/psychres Psychiatry Research 0165-1781/$ - see front matter & 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.psychres.2012.09.057 n Correspondence to: Research Unit, Geha Mental Health Center, 1 Helsinki Street, PO Box 102, Petach Tikva 49100, Israel. Tel.: þ972 523 740040; fax: þ972 3 9241041. E-mail address: neuron.o.d.m@gmail.com (O. Meiron). Psychiatry Research 209 (2013) 1–8