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Journal ArticleDOI

Failure to deactivate in the prefrontal cortex in schizophrenia: dysfunction of the default mode network?

TL;DR: Patients with schizophrenia show both failure to activate and failure to deactivate during performance of a working memory task, including an area in the anterior prefrontal/anterior cingulate cortex that corresponds to one of the two midline components of the ‘default mode network’ implicated in functions related to maintaining one's sense of self.
Abstract: BackgroundFunctional imaging studies using working memory tasks have documented both prefrontal cortex (PFC) hypo- and hyperactivation in schizophrenia. However, these studies have often failed to consider the potential role of task-related deactivation.MethodThirty-two patients with chronic schizophrenia and 32 age- and sex-matched normal controls underwent functional magnetic resonance imaging (fMRI) scanning while performing baseline, 1-back and 2-back versions of the n-back task. Linear models were used to obtain maps of activations and deactivations in the groups.ResultsThe controls showed activation in the expected frontal regions. There were also clusters of deactivation, particularly in the anterior cingulate/ventromedial PFC and the posterior cingulate cortex/precuneus. Compared to the controls, the schizophrenic patients showed reduced activation in the right dorsolateral prefrontal cortex (DLPFC) and other frontal areas. There was also an area in the anterior cingulate/ventromedial PFC where the patients showed apparently greater activation than the controls. This represented a failure of deactivation in the schizophrenic patients. Failure to activate was a function of the patients' impaired performance on the n-back task, whereas the failure to deactivate was less performance dependent.ConclusionsPatients with schizophrenia show both failure to activate and failure to deactivate during performance of a working memory task. The area of failure of deactivation is in the anterior prefrontal/anterior cingulate cortex and corresponds to one of the two midline components of the ‘default mode network’ implicated in functions related to maintaining one's sense of self.
Citations
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Journal ArticleDOI
TL;DR: The findings suggest that altered activity and connectivity of the right dlPFC appears to be related to genetic vulnerability for schizophrenia and may represent a potential endophenotype of the disorder.

86 citations

Journal ArticleDOI
TL;DR: These findings identify a novel biomarker and putative mechanism of WM deficits in patients with schizophrenia, a reduction or flattening of the inverted-U relationship between activation and WM load observed in healthy individuals in left dorsolateral prefrontal cortex.

83 citations

Dissertation
01 Jan 2011

82 citations


Cites background from "Failure to deactivate in the prefro..."

  • ...In schizophrenia, there is evidence of abnormally high functional connectivity within the default mode network during rest and task (Pomarol-Clotet et al., 2008; Whitfield-Gabrieli et al., 2009), while structural connectivity as measured by white matter and grey matter density is decreased (Chua et al....

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Journal ArticleDOI
TL;DR: The default mode network is proposed as a biomarker for monitoring the therapeutic effects of meditation practices in mental disorders, and recent findings support this perspective and indicate the utility of DMN monitoring in understanding and developing meditative treatments for these debilitating conditions.
Abstract: The default mode network (DMN) is a group of anatomically separate regions in the brain found to have synchronized patterns of activation in functional magnetic resonance imaging (fMRI). Mentation associated with the DMN includes processes such as mind wandering, autobiographical memory, self-reflective thought, envisioning the future, and considering the perspective of others. Abnormalities in the DMN have been linked to symptom severity in a variety of mental disorders indicating that the DMN could be used as a biomarker for diagnosis. These correlations have also led to the use of DMN modulation as a biomarker for assessing pharmacological treatments. Concurrent research investigating the neural correlates of meditation, have associated DMN modulation with practice. Furthermore, meditative practice is increasingly understood to have a beneficial role in the treatment of mental disorders. Therefore we propose the use of DMN measures as a biomarker for monitoring the therapeutic effects of meditation practices in mental disorders. Recent findings support this perspective, and indicate the utility of DMN monitoring in understanding and developing meditative treatments for these debilitating conditions.

76 citations


Cites background from "Failure to deactivate in the prefro..."

  • ...…in connectivity between subregions of the DMN – has been associated with a number of psychological disorders such as schizophrenia (Garrity, 2007; Pomarol-Clotet et al., 2008; Camchong et al., 2011; Bastos-Leite et al., 2014), epilepsy (Liao et al., 2010), anxiety (Zhao et al., 2007),…...

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  • ...…activity and connectivity, investigations in schizophrenia reveal increases in DMN activity during task performance as well as increased connectivity relative to controls (Garrity, 2007; Pomarol-Clotet et al., 2008; Whitfield-Gabrieli et al., 2009; Camchong et al., 2011; Bastos-Leite et al., 2014)....

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Journal ArticleDOI
TL;DR: Results of neuroimaging studies that investigated acute and non-acute effects of cannabis on human learning and memory function, both in adults and in adolescents show that cannabis use is associated with a pattern of increased activity and a higher level of deactivation in different memory-related areas.
Abstract: Smoking cannabis produces a diverse range of effects, including impairments in learning and memory. These effects are exerted through action on the endocannabinoid system, which suggests involvement of this system in human cognition. Learning and memory deficits are core symptoms of psychiatric and neurological disorders such as schizophrenia and Alzheimer's disease, and may also be related to endocannabinoid dysfunction in these disorders. However, before new research can focus on potential treatments that work by manipulating the endocannabinoid system, it needs to be elucidated how this system is involved in symptoms of psychiatric disorders. Here we review neuroimaging studies that investigated acute and non-acute effects of cannabis on human learning and memory function, both in adults and in adolescents. Overall, results of these studies show that cannabis use is associated with a pattern of increased activity and a higher level of deactivation in different memory-related areas. This could reflect either increased neural effort ('neurophysiological inefficiency') or a change in strategy to maintain good task performance. However, the interpretation of these findings is significantly hampered by large differences between study populations in cannabis use in terms of frequency, age of onset, and time that subjects were abstinent from cannabis. Future neuroimaging studies should take these limitations into account, and should focus on the potential of cannabinoid compounds for treatment of cognitive symptoms in psychiatric disorders.

74 citations


Cites background from "Failure to deactivate in the prefro..."

  • ...Impairments in capacity to deactivate brain areas during the performance of a cognitive task have been demonstrated for schizophrenia patients [93, 94], youths with ADHD [95, 96], and patients with Alzheimer’s disease [97]....

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References
More filters
Journal ArticleDOI
TL;DR: A review of the research carried out by the Analysis Group at the Oxford Centre for Functional MRI of the Brain (FMRIB) on the development of new methodologies for the analysis of both structural and functional magnetic resonance imaging data.

12,097 citations

Book
01 Jan 1966
TL;DR: This book discusses statistical decision theory and sensory processes in signal detection theory and psychophysics and describes how these processes affect decision-making.
Abstract: Book on statistical decision theory and sensory processes in signal detection theory and psychophysics

11,820 citations


"Failure to deactivate in the prefro..." refers methods in this paper

  • ...The behavioural measure used was the signal detection theory index of sensitivity, dk (Green & Swets, 1966)....

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Journal ArticleDOI
TL;DR: A baseline state of the normal adult human brain in terms of the brain oxygen extraction fraction or OEF is identified, suggesting the existence of an organized, baseline default mode of brain function that is suspended during specific goal-directed behaviors.
Abstract: A baseline or control state is fundamental to the understanding of most complex systems. Defining a baseline state in the human brain, arguably our most complex system, poses a particular challenge. Many suspect that left unconstrained, its activity will vary unpredictably. Despite this prediction we identify a baseline state of the normal adult human brain in terms of the brain oxygen extraction fraction or OEF. The OEF is defined as the ratio of oxygen used by the brain to oxygen delivered by flowing blood and is remarkably uniform in the awake but resting state (e.g., lying quietly with eyes closed). Local deviations in the OEF represent the physiological basis of signals of changes in neuronal activity obtained with functional MRI during a wide variety of human behaviors. We used quantitative metabolic and circulatory measurements from positron-emission tomography to obtain the OEF regionally throughout the brain. Areas of activation were conspicuous by their absence. All significant deviations from the mean hemisphere OEF were increases, signifying deactivations, and resided almost exclusively in the visual system. Defining the baseline state of an area in this manner attaches meaning to a group of areas that consistently exhibit decreases from this baseline, during a wide variety of goal-directed behaviors monitored with positron-emission tomography and functional MRI. These decreases suggest the existence of an organized, baseline default mode of brain function that is suspended during specific goal-directed behaviors.

10,708 citations


"Failure to deactivate in the prefro..." refers background or result in this paper

  • ...This interpretation is supported by (a) the spatial correspondence between this area and that identified in studies of the default mode network (e.g. Gusnard et al. 2001 ; Raichle et al. 2001), and (b) the fact that the controls in our study showed deactivation in the same area while performing the n-back task....

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  • ...the inferior parietal cortex and parts of the temporal lobe including the hippocampus), these are thought to constitute a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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  • ...…is supported by (a) the spatial correspondence between this area and that identified in studies of the default mode network (e.g. Gusnard et al. 2001 ; Raichle et al. 2001), and (b) the fact that the controls in our study showed deactivation in the same area while performing the n-back task....

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  • ...…a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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Journal ArticleDOI
TL;DR: This study constitutes, to the knowledge, the first resting-state connectivity analysis of the default mode and provides the most compelling evidence to date for the existence of a cohesive default mode network.
Abstract: Functional imaging studies have shown that certain brain regions, including posterior cingulate cortex (PCC) and ventral anterior cingulate cortex (vACC), consistently show greater activity during resting states than during cognitive tasks. This finding led to the hypothesis that these regions constitute a network supporting a default mode of brain function. In this study, we investigate three questions pertaining to this hypothesis: Does such a resting-state network exist in the human brain? Is it modulated during simple sensory processing? How is it modulated during cognitive processing? To address these questions, we defined PCC and vACC regions that showed decreased activity during a cognitive (working memory) task, then examined their functional connectivity during rest. PCC was strongly coupled with vACC and several other brain regions implicated in the default mode network. Next, we examined the functional connectivity of PCC and vACC during a visual processing task and show that the resultant connectivity maps are virtually identical to those obtained during rest. Last, we defined three lateral prefrontal regions showing increased activity during the cognitive task and examined their resting-state connectivity. We report significant inverse correlations among all three lateral prefrontal regions and PCC, suggesting a mechanism for attenuation of default mode network activity during cognitive processing. This study constitutes, to our knowledge, the first resting-state connectivity analysis of the default mode and provides the most compelling evidence to date for the existence of a cohesive default mode network. Our findings also provide insight into how this network is modulated by task demands and what functions it might subserve.

6,025 citations


"Failure to deactivate in the prefro..." refers background in this paper

  • ...the inferior parietal cortex and parts of the temporal lobe including the hippocampus), these are thought to constitute a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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  • ...…a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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Journal ArticleDOI
TL;DR: This work explores the possibility that there might be a baseline or resting state of brain function involving a specific set of mental operations, including the manner in which a baseline is defined and the implications of such a baseline for the understanding ofbrain function.
Abstract: Functional brain imaging in humans has revealed task-specific increases in brain activity that are associated with various mental activities. In the same studies, mysterious, task-independent decreases have also frequently been encountered, especially when the tasks of interest have been compared with a passive state, such as simple fixation or eyes closed. These decreases have raised the possibility that there might be a baseline or resting state of brain function involving a specific set of mental operations. We explore this possibility, including the manner in which we might define a baseline and the implications of such a baseline for our understanding of brain function.

3,285 citations


"Failure to deactivate in the prefro..." refers background or result in this paper

  • ...Two studies, however, had opposite results to ours : Harrison et al. (2007) found that 12 schizophrenic patients showed greater deactivation of both the anterior and posterior cingulate midline loci than in 14 controls during a task requiring response suppression. Using an auditory oddball task, Garrity et al. (2007) found that 21 patients with schizophrenia showed a complex pattern of abnormality compared to 22 normal controls, but deactivation was increased in the anterior cingulate/ superior medial frontal gyri. The remaining two studies (Bluhm et al. 2007 ; Zhou et al. 2007) focused exclusively on connectivity, and cannot be directly compared with our findings. Of note, Kennedy et al. (2006) have also documented default mode network dysfunction in adult high-functioning autisticspectrum patients, although they found that the failure of deactivation affected both the anterior and posterior midline loci of the network....

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  • ...Gusnard et al. 2001 ; Raichle et al. 2001), and (b) the fact that the controls in our study showed deactivation in the same area while performing the n-back task. Menzies et al. (2007) also interpreted the failure to deactivate they found in schizophrenia in terms of default mode network dysfunction. However, as neither we nor Menzies et al. (2007) set out specifically to examine default mode network function in schizophrenia, such an interpretation should be regarded as provisional....

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  • ...Two studies, however, had opposite results to ours : Harrison et al. (2007) found that 12 schizophrenic patients showed greater deactivation of both the anterior and posterior cingulate midline loci than in 14 controls during a task requiring response suppression. Using an auditory oddball task, Garrity et al. (2007) found that 21 patients with schizophrenia showed a complex pattern of abnormality compared to 22 normal controls, but deactivation was increased in the anterior cingulate/ superior medial frontal gyri....

    [...]

  • ...the inferior parietal cortex and parts of the temporal lobe including the hippocampus), these are thought to constitute a ‘default mode network’ that is active at rest or when engaging in ‘stimulus-independent’ thought, but which undergoes a reduction in activity when attentiondemanding goal-directed cognition needs to be undertaken (Gusnard et al. 2001 ; Raichle et al. 2001 ; Greicius et al. 2003 ; Gusnard, 2005)....

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  • ...Gusnard et al. (2001) have also reviewed various lines of evidence that suggest that different parts of the default mode network are involved in gathering information about the world, orienting oneself to salient environmental stimuli, theory of mind and self-representation....

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How long can a schizophrenic go without sleep?

This represented a failure of deactivation in the schizophrenic patients.