کنترل شناختی و اسکیزوفرنی: بزرگترین قابلیت اطمینان کار استروپ
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|30225||2015||7 صفحه PDF||سفارش دهید||5898 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Psychiatry Research, Volume 227, Issue 1, 30 May 2015, Pages 10–16
Three components of cognitive inhibition were compared in patients with schizophrenia and healthy controls. Nineteen patients with schizophrenia were compared to 30 healthy controls, matched for age, sex, and educational level. Cognitive inhibition was examined by (i) access to relevant information (Reading with distraction task), (ii) suppression of no longer relevant information (Trail Making Test B), and (iii) restraint of cognitive resources to relevant information (Stroop Test, Hayling Sentence Completion Test, Go/No-Go Test). Beck Depression Inventory, and Positive and Negative Syndrome Scale were also used. Compared to healthy controls, patients with schizophrenia and stabilized for at least 6 months were slower in the inhibition condition at the Stroop task, read more distractors at the RWD, and made more perseverative errors at the TMT, even after controlling for age, Mini-Mental State Examination score, information speed processing, and accuracy. This difference remained significant after taking into account the level of depressive symptoms and the severity of psychotic symptoms. In multivariate analyses, only the Stroop interference index explained cognitive inhibition deficit in patients with schizophrenia. The abnormal cognitive inhibition process observed in patients with schizophrenia could therefore concerns the ability to restraint, rather than the access or the suppression processes.
It is becoming increasingly clear that schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions involved in executive functions (Raffard and Bayard, 2012). Executive control, usually enabling to flexibly adapt behavior to meet current demands (Barch et al., 2009), is one of the most clearly impaired cognitive features of schizophrenia, especially in the face of ambiguous, complex and or changing environments (Botvinick et al., 2001). Thus, cognitive control impairment has been hypothesized to also reduce one׳s ability to respond adaptively to stressors. Executive control is a general ability that underlies performance on different types of tests, including those assessing task switching, cognitive inhibition, error detection, response conflict and cognitive flexibility (Miller and Cohen, 2001). Regarding clinical impact, a deficit in executive control in schizophrenia was associated with social isolation, poor interpersonal relationships (Bozikas et al., 2006), reduced quality of life (Addington and Addington, 2000), and low self-esteem (Wang et al., 2013a). Cognitive inhibition, a major component of executive control which is required for active suppression, limiting the processing of irrelevant stimuli for an on-going task (Shallice and Burgess, 1991), may be deficient in schizophrenia. Several studies have reported impaired inhibitory control in schizophrenia (Enticott et al., 2008, Kiehl et al., 2000, Raemaekers et al., 2002, Tan and Rossell, 2014, Wang et al., 2013b and Zandbelt et al., 2011), but others have not (Badcock et al., 2002, Nishimura et al., 2011 and Rubia et al., 2001). This may be due to the fact that cognitive inhibition is probably a heterogeneous concept (Hasher et al., 1999), the latter studies having used a variety of tasks measuring different aspects of inhibition (Aron, 2007). According to Hasher and Zacks (Hasher et al., 1999), inhibitory mechanisms indeed serve to (i) restrict access to relevant information, (ii) suppress information that is no longer relevant, and (iii) restrain production of strong but potentially incorrect retrieval of information from working memory (Zacks et al., 1999). Furthermore, only one pilot study (Gigaux et al., 2013) explored the Hasher and Zacks׳ paradigm of cognitive inhibition (Hasher et al., 1999) in schizophrenia. Since most of the studies were behavioral, the neural mechanisms underlying impaired inhibitory control in schizophrenia remain largely unknown. Nevertheless, it is not clear to what extent cognitive inhibition deficits are heterogeneous in schizophrenia patients. Furthermore, it has been shown that attention and executive function (including response inhibition) predicted level of global functioning (Hegde et al., 2013). Multiple studies have demonstrated that cognitive control impairments in schizophrenia are largely mediated by slowed information processing speed (Hegde et al., 2013). Apart from understanding more clearly the types of cognitive deficits associated with schizophrenia, research works devoted to inhibition deficits could provide which aspect of cognitive inhibition is driving most of its abnormality when taking into account numerous intermediate markers of schizophrenia, potentially offering targets of therapeutic interventions aimed at adapting the long-term management of care. The aim of this study was to verify the abnormality of cognitive inhibition ability in patients with schizophrenia during the stabilization phase of their disease compared to healthy controls, in order to disentangle which component of cognitive inhibition is the most specifically impaired, even when potential confounders are taken into account. We hypothesized that patients with schizophrenia would show a significant deficit in cognitive inhibition, and that the three aspects of inhibition process (access, suppression and restraint) would be heterogeneously impaired. Impact of poor inhibition may explain high levels of co-morbid substance abuse associated with the disorder (Chambers et al., 2001), violent offending in patients suffering from schizophrenia (Enticott et al., 2008), a predisposition to hallucinations (Paulik et al., 2008) and frequency of hallucinations in schizophrenic patients (Waters et al., 2003), and may also predict poor occupational and social outcome (Reeder et al., 2004). The level of cognitive functioning has been shown to be an important predictor for recovery and functional outcome (Harvey et al., 1998 and Kurtz et al., 2008), underlining the importance of achieving a better understanding of the nature of cognitive deficits associated with schizophrenia in order to optimize rehabilitation and intervention programs. Indeed, cognitive remediation could be adapted to focus more precisely on these cognitive functions in order to improve or avoid the decrease of such cognitive skills.