Title: Cognitive Control in Schizophrenia
Description: Schizophrenia is the ninth leading cause of disability worldwide (e.g., Lopez et al., 2006), and is a devastating psychiatric illness. Although diagnosis is made based upon the occurrence of positive and negative symptoms (First, Spitzer, Gibbon & Williams, 1995), it is the cognitive symptoms that are most strongly associated with functional outcome (Green, 1996 ). Cognitive control, including the ability to appropriately update relevant information and resist interference from irrelevant information, is critical for flexible and adaptive goal-directed behavior, and is among the most frequently noted of the cognitive symptoms in schizoprenia (Barch, 2005; Barch & Smith, 2008). Despite this, deficits in cognitive control are unaffected by medications used to treat the clinical symptoms of the disorder (Greene et al, 2008). Understanding both the behavioral and the neural mechanisms that comprise this deficit is thus of paramount importance. Although deficits in cognitive control in schizoprenia have been extensively studied, a number of questions still remain.

Here, I ask two main questions: First, is cognitive control impaired globally, or are only certain aspects of cognitive control impaired in schizophrenia? I found that that there are (at least) two different selection mechanisms, and that people with schizophrenia are impaired in only one of these: dysregulation in left posterior ventrolateral prefrontal cortex correlates with impaired behavioral performance on a working memory task, suggesting that deficits in inhibiting irrelevant information from working memory is the crux of the deficit. Second, I asked whether the nature of the information affects cognitive control. I found that people with schizophrenia are able to deploy cognitive control processes more effectively than healthy controls in cases in which salient, emotional information competes with active cognitive goals, suggesting specific underlying deficits in emotional processing.