A Functional Magnetic Resonance Imaging Study of Working Memory Abnormalities in Schizophrenia

Johnson, Matthew; Morris, Nicholas; Astur, Robert S.; Calhoun, Vince D.; Mathalon, Daniel H.; Kiehl, Kent A.; Pearlson, Godfrey D.

doi:10.1016/j.biopsych.2005.11.012

Cited by 116 publications

(111 citation statements)

References 39 publications

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“…These regions also show abnormal functionality in patients with schizophrenia during working memory tasks (Johnson et al, 2006). Basic studies suggest that BA 10 is involved in sub-goal processing and integration of information (De Pisapia et al, 2007) as well as control processes underlying activation of an attentional set or 'retrieval mode' rather than trial by trial retrieval (Velanova et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

Prefrontal Cortical Changes Following Cognitive Training in Patients with Chronic Schizophrenia: Effects of Practice, Generalization, and Specificity

Haut

Lim

MacDonald

2010

Neuropsychopharmacol

153

120

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Cognitive training is increasingly used in the treatment of schizophrenia, but it remains unknown how this training affects functional neuroanatomy. Practice on specific cognitive tasks generally leads to automaticity and decreased prefrontal cortical activity, yet broadbased cognitive training programs may avoid automaticity and increase prefrontal cortex (PFC) activity. This study used quasirandomized, placebo-control design and pre/post neuroimaging to examine functional plasticity associated with attention and working memory-focused cognitive training in patients with schizophrenia. Twenty-one participants with schizophrenia or schizoaffective disorder split into two demographically and performance matched groups (nine scanned per group) and nine control participants were tested 6-8 weeks apart. Compared with both patient controls and healthy controls, patients receiving cognitive training increased activation significantly more in attention and working memory networks, including dorsolateral prefrontal cortex, anterior cingulate and frontopolar cortex. The extent to which activity increased in a subset of these regions predicted performance improvements. Although this study was not designed to speak to the efficacy of cognitive training as a treatment, it is the first study to show that such training can increase the ability of patients to activate the PFC regions subserving attention and working memory.

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Section: Discussionmentioning

confidence: 99%

Prefrontal Cortical Changes Following Cognitive Training in Patients with Chronic Schizophrenia: Effects of Practice, Generalization, and Specificity

Haut

Lim

MacDonald

2010

Neuropsychopharmacol

153

120

View full text Add to dashboard Cite

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“…Indeed, several other investigators using cognitive control (Lesh et al, 2015) and WM (Johnson et al, 2006;Walter et al, 2007) tasks have also reported no significant difference in dlPFC activation during correct trials between medicated first-episode schizophrenia patients and healthy individuals. Further, in our study, although positive symptoms negatively correlated with activation in FPCN (echoing previous results from Menon et al, 2001), patients still showed normal activation of the network during correct trials.…”

Section: Fpcn Function and Its Relation To Performance In Schizophreniamentioning

confidence: 95%

“…Schizophrenia patients frequently perform worse than controls in WM tasks (Johnson et al, 2006;Meda et al, 2009), confounding brain activation differences when the groups are compared at the same WM load. This is especially problematic in block designs that average across correct and error trials.…”

Section: Introductionmentioning

confidence: 99%

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Disrupted Working Memory Circuitry in Schizophrenia: Disentangling fMRI Markers of Core Pathology vs Other Aspects of Impaired Performance

Eryilmaz

Tanner

et al. 2016

Neuropsychopharmacol

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Working memory (WM) impairment, a core feature of schizophrenia, is often associated with aberrant dorsolateral prefrontal cortex (dlPFC) activation. Reduced resting-state connectivity within the frontoparietal control network (FPCN) has also been reported in schizophrenia. However, interpretation of WM-related dlPFC dysfunction has been limited by performance differences between patients and controls, and by uncertainty over the relevance of resting-state connectivity to network engagement during task. We contrasted brain activation in 40 schizophrenia patients and 40 controls during verbal WM performance, and evaluated underlying functional connectivity during rest and task. During correct trials, patients demonstrated normal FPCN activation, despite an inverse relationship between positive symptoms and activation. FPCN activation differed between the groups only during error trials (controls4patients). In contrast, controls demonstrated stronger deactivation of the ventromedial prefrontal cortex (vmPFC) during correct and error trials. Functional connectivity analysis indicated impaired resting-state FPCN connectivity in patients, but normal connectivity during task. However, patients showed abnormal connectivity among regions such as vmPFC, lateral orbitofrontal cortex, and parahippocampal gyrus (PHG) during both rest and task. During task, patients also exhibited altered thalamic connectivity to PHG and FPCN. Activation and connectivity patterns that were more characteristic of controls generally correlated with better performance. In summary, patients demonstrated normal FPCN activation when they remained on-task, and exhibited normal FPCN connectivity during WM, whereas vmPFC deactivation differences persisted regardless of WM performance. Our findings suggest that altered FPCN activation in patients reflects performance difference, and that limbic and thalamic dysfunction is critically involved in WM deficits in schizophrenia.

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“…Alternatively, it has been suggested that which of the two abnormalities is seen depends on the demands of the task: hyperfrontality appears when the task is easy and schizophrenic patients 'work harder to keep up'. At higher levels of task difficulty, schizophrenic patients reach their limit of performance earlier than controls and thereafter fail to activate their prefrontal cortex, resulting in hypofrontality (Johnson et al, 2006, Weinberger et al, 2001.…”

Section: Functional Imaging Studies In Schizoaffective Disordermentioning

confidence: 99%

Neuropsychological and Brain Functional Changes Across the Different Phases of Schizoaffective Disorder

Merce

Raduà

Amann

2015

European Psychiatry

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Schizoaffective disorder was first described by J. Kasanin in 1933, since then its nosology remains a matter of controversy. We aim to add further neurobiological findings to this debate.Memory and executive function were tested in 22 acutely ill schizoaffective patients; they also underwent fMRI scanning during performance of the n-back working memory test. The same measures were obtained after they had been in remission for ≥2 months. 22 matched healthy individuals were also examined.Compared to controls, acute schizoaffective patients showed reduced activation in the DLPFC and also a failure of deactivation in the medial frontal cortex (1).In clinical remission, schizomanic patients showed an improvement of memory but not of executive function, while schizodepressive patients did not change in either domain. All schizoaffective patients in clinical remission showed memory and executive impairment compared to the controls. On fMRI, acutely ill schizomanic patients had reversible frontal hypo-activation when compared to clinical remission, while activation patterns in ill and remitted schizodepressive patients were similar. The whole group of schizoaffective patients in clinical remission showed a failure of de-activation in the medial frontal gyrus compared to the healthy controls. There was evidence for memory improvement and state dependent changes in activation in schizomanic patients across relapse and remission (2).The results demonstrate that schizoaffective disorder is characterized by medial frontal failure of deactivation and hence default mode network dysfunction (3), which is present during both active illness and remission suggesting that it is a trait factor for the disorder.

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A Functional Magnetic Resonance Imaging Study of Working Memory Abnormalities in Schizophrenia

Cited by 116 publications

References 39 publications

Prefrontal Cortical Changes Following Cognitive Training in Patients with Chronic Schizophrenia: Effects of Practice, Generalization, and Specificity

Prefrontal Cortical Changes Following Cognitive Training in Patients with Chronic Schizophrenia: Effects of Practice, Generalization, and Specificity

Disrupted Working Memory Circuitry in Schizophrenia: Disentangling fMRI Markers of Core Pathology vs Other Aspects of Impaired Performance

Neuropsychological and Brain Functional Changes Across the Different Phases of Schizoaffective Disorder

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