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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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01 Jan 2016
TL;DR: This thesis has addressed this fundamental knowledge gap by using an imaging based approach to quantify and describe early life patterns of fat deposition, shed new insights on perinatal brain development, and identify prospective associations between interoceptive, reward, and gustatory properties of the newborn brain and subsequent early life fat gain.
Abstract: Storage of adipose tissue is a trait belonging to all humans, historically borne from the necessity to survive extended periods of famine. Yet, there is clear inter-individual variability in our propensity to accumulate excess fat. In addition, this variability is present as early as infancy and persists into adulthood. In adults, the regulation of energy homeostasis (balance) by the brain is evident not only through signaling provided by peripheral systems to the hypothalamus, such as fat (leptin) and the stomach (ghrelin), but also by the downstream cognition required to decide what, when and how much to eat. Magnetic Resonance Imaging has been instrumental in identifying the brain regions and circuitry involved in food-related behaviors as well as the identification of brain differences between obese and normal weight adults. It is, however, unclear whether the observed differences in brain regions and circuitry in obese relative to normal weight individuals are a cause, consequence, or both, of the obese state. Moreover, relatively little is known about the developmental ontogeny of these food-related brain regions and circuitry, particularly during the period of intrauterine development (when the postnatal obesogenic environment could not yet have affected this circuitry), and its prospective role in shaping propensity for childhood obesity. Knowledge of early life brain structure and function in the context of energy imbalance would contribute to an improved understanding of propensity for obesity, early identification of at-risk individuals, and intervention targets for primary prevention. This thesis has addressed this fundamental knowledge gap by using an imaging based approach to: 1) quantify and describe early life patterns of fat deposition, 2) shed new insights on perinatal brain development, and 3) identify prospective associations between interoceptive, reward, and gustatory properties of the newborn brain and subsequent early life fat gain.

1 citations


Additional excerpts

  • ... A  number   of  disorders  have  been  shown  to  alter  the  DMN  including  schizophrenia(Garrity,  Pearlson,   McKiernan,  &  Lloyd,  2007;  Pomarol-‐Clotet  et  al.,  2008),  bipolar  disorder(Ongür  et  al.,  2010),   depression(Coutinho   et   al.,   2015),   Alzheimer’s,   ADHD,   and   as…...

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  • ... A  number   of  disorders  have  been  shown  to  alter  the  DMN  including  schizophrenia(Garrity,  Pearlson,   McKiernan,  &  Lloyd,  2007;  Pomarol-‐Clotet  et  al.,  2008),  bipolar  disorder(Ongür  et  al.,  2010),   depression(Coutinho   et   al.,   2015),   Alzheimer’s,   ADHD,   and   as  will   be   discussed   in   detail   further   down,   obesity....

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Posted ContentDOI
17 Oct 2020-bioRxiv
TL;DR: A causal link between the cortisol awakening response and its proactive role in optimizing brain functional networks involved in neuroendocrine control and memory is established.
Abstract: Upon awakening from nighttime sleep, the stress hormone cortisol exhibits a burst in the morning within 30-minutes in humans. This cortisol awakening response (CAR) is thought to prepare the brain for upcoming challenges. Yet, the neurobiological mechanisms underlying the CAR-mediated 9preparation9 function remains unknown. Using blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD-fMRI) with a dedicated prospective design and pharmacological manipulation, we investigated this proactive mechanism in humans across two fMRI studies. In Study 1, we found that a robust CAR was predictive of less hippocampal and prefrontal activity, though enhanced functional coupling between those regions and facilitated working memory performance, during a demanding task later in the afternoon. These results implicate the CAR in proactively promoting brain preparedness based on improved neural efficiency. To address the causality of this proactive effect, we conducted a second study (Study 2) in which we suppressed the CAR with a double blind, placebo controlled, randomized design using Dexamethasone. We found that pharmacological suppression of CAR mirrored the proactive effects from Study 1. Dynamic causal modeling analyses further revealed a reduction of prefrontal top-down modulation over hippocampal activity when performing a cognitively demanding task in the afternoon. These findings establish a causal link between the CAR and its proactive role in optimizing brain functional networks involved in neuroendocrine control and memory.

1 citations

Journal Article
TL;DR: In this article, the authors schetsen een beknopte geschiedenis van de functionele neurobeeldvormingstechnieken om de plaats van fmri voor de opsporing van disfunctionele netwerken bij schizofrenie duidelijk te maken.
Abstract: Achtergrond: Functionele magnetische-resonantiebeeldvorming (fmri) is een belangrijk onderzoeksinstrument voor het opsporen van neurale netwerkproblemen bij schizofrenie. Het belang van een aangepaste taak voor het onderzoek met fmri bij schizofrenie blijft echter vaak onderbelicht. Doel: Aantonen hoe de keuze van een taak fmri-resultaten bij schizofrenie op hersenniveau beinvloedt, in het bijzonder door prestatiegerelateerde problemen. methode We schetsen een beknopte geschiedenis van de functionele neurobeeldvormingstechnieken om de plaats van fmri voor de opsporing van disfunctionele netwerken bij schizofrenie duidelijk te maken. Ook maken we duidelijk waarom door de snelle ontwikkeling van de techniek en analysemethodes bij beeldvormingstechnieken de keuze van de taak in de scanner een steeds groter belang krijgt voor het meten van specifieke verschillen bij psychiatrische stoornissen. Resultaten: Met voorbeelden uit eigen onderzoek illustreren wij het complexe verband tussen cognitieve problemen bij patienten met schizofrenie tijdens de taakuitvoering en verschillen in hersenactiviteit gemeten met fmri. Het belang van taakonafhankelijke neurale netwerken voor de interpretatie van dit verband wordt toegelicht. Conclusie: De ontwikkeling van taken waarbij vermeden wordt dat prestatieverschillen door aspecifieke factoren zoals demotivatie of opgave neurale activiteit beinvloeden, is cruciaal voor het verder onderzoek met fmri bij schizofrenie.

1 citations

Book ChapterDOI
01 Jan 2015

1 citations

References
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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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Trending Questions (1)
How long can a schizophrenic go without sleep?

This represented a failure of deactivation in the schizophrenic patients.