Journal ArticleDOI
Failure to deactivate in the prefrontal cortex in schizophrenia: dysfunction of the default mode network?
Edith Pomarol-Clotet,Raymond Salvador,Salvador Sarró,Jesus J. Gomar,Fidel Vila,A. Martínez,A. Guerrero,Jordi Ortiz-Gil,Bibiana Sans-Sansa,Antoni Capdevila,J. M. Cebamanos,Peter J. McKenna +11 more
TLDR
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.read more
Citations
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Journal ArticleDOI
Acute psychological stress reduces working memory-related activity in the dorsolateral prefrontal cortex.
TL;DR: It is demonstrated that experimentally induced acute stress in healthy volunteers results in a reduction of WM-related DLPFC activity and reallocation of neural resources away from executive function networks, which may be explained by supraoptimal levels of catecholamines potentially in conjunction with elevated levels of cortisol.
Journal ArticleDOI
The default-mode, ego-functions and free-energy: a neurobiological account of Freudian ideas
TL;DR: The notion that Freudian constructs may have neurobiological substrates is explored by showing that Freud’s descriptions of the primary process are consistent with the phenomenology and neurophysiology of rapid eye movement sleep, the early and acute psychotic state, the aura of temporal lobe epilepsy and hallucinogenic drug states.
Journal ArticleDOI
Alteration of brain default network in subacute phase of injury in concussed individuals: resting-state fMRI study.
Brian F. G. Johnson,Kai Zhang,Silvina G. Horovitz,Mark Hallett,Wayne J. Sebastianelli,Semyon Slobounov +5 more
TL;DR: In this article, the authors used resting state functional magnetic resonance imaging to evaluate the default mode network (DMN) in the subacute phase of mild traumatic brain injury (mTBI).
Journal ArticleDOI
Dysregulation of working memory and default‐mode networks in schizophrenia using independent component analysis, an fBIRN and MCIC study
Dae Il Kim,Dara S. Manoach,Daniel H. Mathalon,Jessica A. Turner,Maggie V. Mannell,Greg G. Brown,Judith M. Ford,Randy L. Gollub,Tonya White,Cynthia G. Wible,Aysenil Belger,Aysenil Belger,H. Jeremy Bockholt,Vince P. Clark,Vince P. Clark,John Lauriello,Daniel S. O'Leary,Bryon A. Mueller,Kelvin O. Lim,Nancy C. Andreasen,S.G. Potkin,Vince D. Calhoun,Vince D. Calhoun +22 more
TL;DR: The results suggest that DLPFC dysfunction in schizophrenia might be lateralized to the left and intrinsically tied to other regions such as the inferior parietal lobule and cingulate gyrus, and suggests that both task‐correlated and task‐anticorrelated networks may serve as potential biomarkers.
Journal ArticleDOI
Altered functional connectivity in default mode network in absence epilepsy: A resting-state fMRI study
Cheng Luo,Qifu Li,Yongxiu Lai,Yang Xia,Yun Qin,Wei Liao,Shasha Li,Dong Zhou,Dezhong Yao,Qiyong Gong +9 more
TL;DR: Findings indicated DMN abnormalities in patients with absence epilepsy, even during resting interictal durations without interdictal epileptic discharges, may reflect abnormal anatomo‐functional architectural integration in DMN, as a result of cognitive mental impairment and unconsciousness during absence seizure.
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