Set shifting and reversal learning in patients with bipolar disorder or schizophrenia
ABSTRACT Bipolar disorder and schizophrenia have both been associated with deficits in extra-dimensional set shifting (EDS). Deficits in reversal learning (RL) have also been shown in schizophrenia but not in bipolar disorder. This study sought to assess the specificity of these findings in a direct comparison of clinically stable patients with each disorder.
The intra-dimensional/extra-dimensional (IDED) set-shifting task, part of the Cambridge Neuropsychological Test Automated Battery (CANTAB), was administered to 30 patients with schizophrenia, 47 with bipolar disorder and a group of 44 unaffected controls. EDS and RL errors were compared between the groups and related to measures of current and past psychiatric symptoms and medication.
Both groups of patients with schizophrenia or bipolar disorder made more EDS and RL errors than controls. Neither measure separated the two disorders, even when the analysis was restricted to euthymic patients. No relationship was found with prescribed medication.
Patients with bipolar disorder or schizophrenia show common deficits in EDS and RL. These deficits do not seem to be attributable to current symptoms and are consistent with disrupted networks involving the ventral prefrontal cortex.
Full-textDOI: · Available from: Andrew Mark Mcintosh, Aug 12, 2015
- SourceAvailable from: Victoria maebh Barker
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- "BPD has been proposed to be part of a spectrum of bipolar affective disorders (Smith, Muir, & Blackwood, 2004). Our findings suggest that this is less likely as subjects with bipolar affective disorder demonstrate deficits in both EDS and later reversal learning stages of the IDED task (McKirdy et al., 2009) and subjects with depression tend to fail at the EDS stage of the task (Purcell et al., 1997; Taylor Tavares et al., 2007), whereas the subjects in our study with BPD do not demonstrate these shortfalls in performing the task. The one stage that BPD subjects did show impaired performance on was the simple reversal stage as indicated by a small to medium effect size. "
ABSTRACT: People with BPD have been shown in some studies to have structural deficits in regions of the prefrontal cortex. A sensitive test of prefrontal cortex function is the intra-dimensional/extra-dimensional (IDED) set shifting task. This study sought to examine whether people with BPD demonstrate impaired performances on extra-dimensional shift (EDS) and reversal learning aspects of this task similar to those seen in conditions such as schizophrenia and bipolar affective disorder. Twenty subjects with BPD and 21 healthy control subjects were administered the IDED task from the Cambridge Neuropsychological Test Automated Battery cognitive test battery. EDS and reversal learning errors were compared between the groups using repeated measures ANOVAs. There was no significant difference between the BPD and control participants in EDS or reversal learning on the IDED task or in stage of the task completed. There was a medium effect size difference (Cohen's d = 0.4) for simple reversal learning and small effect sizes for reversal learning (Cohen' d = 0.17) and IDED shift stages (Cohen's d = 0.2 and -0.3 respectively). Participants with BPD in this study did not show statistically significant deficits in EDS or reversal learning, although small to medium effect sizes were found. These findings distinguish them from sufferers of schizophrenia and bipolar affective disorder and are in keeping with the idea that BPD is a distinct condition with discrete neuropathological processes. Copyright © 2013 John Wiley & Sons, Ltd.Personality and Mental Health 02/2014; 8(1):1-13. DOI:10.1002/pmh.1235 · 1.10 Impact Factor
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- "Manic patients have been reported to show an increased tendency to choose the less likely of two outcomes despite explicit information about the favourability of these outcomes (Murphy et al., 2001). Similarly, blunted reward learning has been found in BD patients on response reversal tasks (Dickstein et al., 2004, 2007; Gorrindo et al., 2005; McKirdy et al., 2009) and when using tasks in which one stimulus is more frequently rewarded than another (Pizzagalli, Goetz, Ostacher, Iosifescu, & Perlis, 2008). As mentioned previously, rewardbased learning is particularly relevant to the BD phenotype given that patients exhibit excessive reward-based orientations in situations in which behavioural withdrawal would be more adaptive (Johnson, 2005). "
ABSTRACT: Introduction. Bipolar Disorder (BD) is a serious mood disorder, the aetiology of which is still unclear. The disorder is characterised by extreme mood variability in which patients fluctuate between markedly euphoric, irritable, and elevated states to periods of severe depression. The current research literature shows that BD patients demonstrate compromised neurocognitive ability in addition to these mood symptoms. Viable candidate genes implicated in neurocognitive and socioemotional processes may explain the development of these core emotion abnormalities. Additionally, links between faulty neurocognition and impaired socioemotional ability complement genetic explanations of BD pathogenesis. This review examines associations between cognition indexing prefrontal neural regions and socioemotional impairments including emotion processing and regulation. A review of the effect of COMT and TPH2 on these functions is also explored. Methods. Major computer databases including PsycINFO, Google Scholar, and Medline were consulted in order to conduct a comprehensive review of the genetic and cognitive literature in BD. Results. This review determines that COMT and TPH2 genetic variants contribute susceptibility to abnormal prefrontal neurocognitive function which oversees the processing and regulation of emotion. This provides for greater understanding of some of the emotional and cognitive symptoms in BD. Conclusions. Current findings in this direction show promise, although the literature is still in its infancy and further empirical research is required to investigate these links explicitly.Cognitive Neuropsychiatry 10/2012; 18. DOI:10.1080/13546805.2012.690938 · 2.18 Impact Factor
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- "A previous study using the change task in healthy adults demonstrated that cognitive flexibility during the task is associated with recruitment of VLPFC, DLPFC, and parietal cortex, as well as striatum (Kenner et al., 2010). Data indicate that both youth and adults with BD show behavioral deficits on cognitive flexibility tasks, including the change (Dickstein et al., 2007; McClure et al., 2005), Wisconsin Card Sort (Fleck et al., 2008; Martinez-Aran et al., 2004), reversal learning (Gorrindo et al., 2005), set-shifting (McKirdy et al., 2009), and response inhibition tasks (McClure et al., 2005; Pavuluri et al., 2006). Functional MRI studies suggest that such deficits are mediated by dysfunction in a variety of regions that participate in flexible responding including DLPFC, VLPFC, parietal association cortex, and striatum (Blumberg et al., 2003; Chang et al., 2004; Dickstein et al., 2010; Passarotti et al., 2010; Singh et al., 2010; Strakowski et al., 2005). "
ABSTRACT: Youth with bipolar disorder (BD) show behavioral and neural deficits in cognitive flexibility; however, whether such deficits exist among youths at risk for BD has not been explored. The current fMRI study examined the neural basis of cognitive flexibility in BD youth (n = 28), unaffected youth at risk for BD (AR; n = 13), and healthy volunteer youth (HV; n = 21) by comparing brain activation patterns while participants performed the change task. On change trials, subjects must inhibit a prepotent response and execute an alternate one. During successful change trials, both BD and AR youth had increased right ventrolateral prefrontal and inferior parietal activity, compared to HV youth. During failed change trials, both BD and AR youth exhibited increased caudate activation relative to HV youth, but BD youth showed increased activation in the subgenual anterior cingulate cortex (ACC) relative to the other two groups. Abnormal activity in ventrolateral prefrontal cortex, inferior parietal cortex, and striatum during a cognitive flexibility task may represent a potential BD endophenotype, but subgenual ACC dysfunction may represent a marker of BD illness itself.Journal of Psychiatric Research 01/2012; 46(1):22-30. DOI:10.1016/j.jpsychires.2011.09.015 · 4.09 Impact Factor