scholarly journals Brain functional abnormality in schizo-affective disorder: an fMRI study

2012 ◽  
Vol 43 (1) ◽  
pp. 143-153 ◽  
Author(s):  
M. Madre ◽  
E. Pomarol-Clotet ◽  
P. McKenna ◽  
J. Radua ◽  
J. Ortiz-Gil ◽  
...  
Keyword(s):  
Frontal Cortex ◽  
Affective Disorder ◽  
Diagnostic Criteria ◽  
Dorsolateral Prefrontal Cortex ◽  
Linear Models ◽  
Medial Frontal Cortex ◽  
Significant Extent ◽  
Functional Abnormality ◽  
Fmri Study ◽  
Dorsolateral Prefrontal

BackgroundSchizo-affective disorder has not been studied to any significant extent using functional imaging. The aim of this study was to examine patterns of brain activation and deactivation in patients meeting strict diagnostic criteria for the disorder.MethodThirty-two patients meeting Research Diagnostic Criteria (RDC) for schizo-affective disorder (16 schizomanic and 16 schizodepressive) and 32 matched healthy controls underwent functional magnetic resonance imaging (fMRI) during performance of the n-back task. Linear models were used to obtain maps of activations and deactivations in the groups.ResultsControls showed activation in a network of frontal and other areas and also deactivation in the medial frontal cortex, the precuneus and the parietal cortex. Schizo-affective patients activated significantly less in prefrontal, parietal and temporal regions than the controls, and also showed failure of deactivation in the medial frontal cortex. When task performance was controlled for, the reduced activation in the dorsolateral prefrontal cortex (DLPFC) and the failure of deactivation of the medial frontal cortex remained significant.ConclusionsSchizo-affective disorder shows a similar pattern of reduced frontal activation to schizophrenia. The disorder is also characterized by failure of deactivation suggestive of default mode network dysfunction.

scholarly journals Automaticity and Reestablishment of Executive Control—An fMRI Study

2006 ◽  
Vol 18 (8) ◽  
pp. 1331-1342 ◽  
Author(s):  
Andrea Kübler ◽  
Veronica Dixon ◽  
Hugh Garavan
Keyword(s):  
Executive Control ◽  
Dorsolateral Prefrontal Cortex ◽  
Search Task ◽  
Visual Search Task ◽  
Cortical Activation ◽  
Automatic Behavior ◽  
Automatic Response ◽  
Fmri Study ◽  
Dorsolateral Prefrontal

The ability to exert control over automatic behavior is of particular importance as it allows us to interrupt our behavior when the automatic response is no longer adequate or even dangerous. However, despite the literature that exists on the effects of practice on brain activation, little is known about the neuroanatomy involved in reestablishing executive control over previously automatized behavior. We present a visual search task that enabled participants to automatize according to defined criteria within about 3 hr of practice and then required them to reassert control without changing the stimulus set. We found widespread cortical activation early in practice. Activation in all frontal areas and in the inferior parietal lobule decreased significantly with practice. Only selected prefrontal (Brodmann's areas [BAs] 9/46/8) and parietal areas (BAs 39/40) were specifically reactivated when executive control was required, underlining the crucial role of the dorsolateral prefrontal cortex in executive control to guide our behavior.

scholarly journals Divergence of rodent and primate medial frontal cortex functional connectivity

2020 ◽  
Vol 117 (35) ◽  
pp. 21681-21689 ◽  
Author(s):  
David J. Schaeffer ◽  
Yuki Hori ◽  
Kyle M. Gilbert ◽  
Joseph S. Gati ◽  
Ravi S. Menon ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Frontal Cortex ◽  
Nonhuman Primates ◽  
Functional Organization ◽  
Brain Connectivity ◽  
Medial Frontal Cortex ◽  
Preclinical Model ◽  
Preclinical Research ◽  
Ultra High Field ◽  
Dorsolateral Prefrontal

With the medial frontal cortex (MFC) centrally implicated in several major neuropsychiatric disorders, it is critical to understand the extent to which MFC organization is comparable between humans and animals commonly used in preclinical research (namely rodents and nonhuman primates). Although the cytoarchitectonic structure of the rodent MFC has mostly been conserved in humans, it is a long-standing question whether the structural analogies translate to functional analogies. Here, we probed this question using ultra high field fMRI data to compare rat, marmoset, and human MFC functional connectivity. First, we applied hierarchical clustering to intrinsically define the functional boundaries of the MFC in all three species, independent of cytoarchitectonic definitions. Then, we mapped the functional connectivity “fingerprints” of these regions with a number of different brain areas. Because rats do not share cytoarchitectonically defined regions of the lateral frontal cortex (LFC) with primates, the fingerprinting method also afforded the unique ability to compare the rat MFC and marmoset LFC, which have often been suggested to be functional analogs. The results demonstrated remarkably similar intrinsic functional organization of the MFC across the species, but clear differences between rodent and primate MFC whole-brain connectivity. Rat MFC patterns of connectivity showed greatest similarity with premotor regions in the marmoset, rather than dorsolateral prefrontal regions, which are often suggested to be functionally comparable. These results corroborate the viability of the marmoset as a preclinical model of human MFC dysfunction, and suggest divergence of functional connectivity between rats and primates in both the MFC and LFC.

scholarly journals Brain functional changes across the different phases of bipolar disorder

2015 ◽  
Vol 206 (2) ◽  
pp. 136-144 ◽  
Author(s):  
Edith Pomarol-Clotet ◽  
Silvia Alonso-Lana ◽  
Noemi Moro ◽  
Salvador Sarró ◽  
Mar C. Bonnin ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Prefrontal Cortex ◽  
Frontal Cortex ◽  
Parietal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Cognitive Task ◽  
Memory Task ◽  
Mixed Effects ◽  
Linear Mixed Effects ◽  
Dorsolateral Prefrontal

BackgroundLittle is known about how functional imaging changes in bipolar disorder relate to different phases of the illness.AimsTo compare cognitive task activation in participants with bipolar disorder examined in different phases of illness.MethodParticipants with bipolar disorder in mania (n = 38), depression (n = 38) and euthymia (n = 38), as well as healthy controls (n = 38), underwent functional magnetic resonance imaging during performance of the n-back working memory task. Activations and de-activations were compared between the bipolar subgroups and the controls, and among the bipolar subgroups. All participants were also entered into a linear mixed-effects model.ResultsCompared with the controls, the mania and depression subgroups, but not the euthymia subgroup, showed reduced activation in the dorsolateral prefrontal cortex, the parietal cortex and other areas. Compared with the euthymia subgroup, the mania and depression subgroups showed hypoactivation in the parietal cortex. All three bipolar subgroups showed failure of de-activation in the ventromedial frontal cortex. Linear mixed-effects modelling revealed a further cluster of reduced activation in the left dorsolateral prefrontal cortex in the patients; this was significantly more marked in the mania than in the euthymia subgroup.ConclusionsBipolar disorder is characterised by mood state-dependent hypoactivation in the parietal cortex. Reduced dorsolateral prefrontal activation is a further feature of mania and depression, which may improve partially in euthymia. Failure of de-activation in the medial frontal cortex shows trait-like characteristics.

scholarly journals Shared neural representations of cognitive conflict and negative affect in the medial frontal cortex

2019 ◽  
Author(s):  
Luc Vermeylen ◽  
David Wisniewski ◽  
Carlos González-García ◽  
Vincent Hoofs ◽  
Wim Notebaert ◽  
...  
Keyword(s):  
Negative Affect ◽  
Frontal Cortex ◽  
Supplementary Motor Area ◽  
Cognitive Conflict ◽  
Medial Frontal Cortex ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Neural Representations ◽  
Fmri Study ◽  
Multivariate Pattern

AbstractInfluential theories of medial frontal cortex (MFC) function suggest that the MFC registers cognitive conflict as an aversive signal, but no study directly tested this idea. Instead, recent studies suggested that non-overlapping regions in the MFC process conflict and affect. In this pre-registered human fMRI study, we used multivariate pattern analyses to identify which regions respond similarly to conflict and aversive signals. The results reveal that, of all conflict- and value-related regions, the ventral pre-supplementary motor area (or dorsal anterior cingulate cortex) showed a shared neural pattern response to different conflict and affect tasks. These findings challenge recent conclusions that conflict and affect are processed independently, and provide support for integrative views of MFC function.

Deficits in Subprocesses of Visual Feature Search after Frontal, Parietal, and Temporal Brain Lesions—A Modeling Approach

2010 ◽  
Vol 22 (7) ◽  
pp. 1399-1424 ◽  
Author(s):  
Gisela Müller-Plath ◽  
Derek V. M. Ott ◽  
Stefan Pollmann
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Dwell Time ◽  
Linear Models ◽  
Parietal Lobe ◽  
Movement Time ◽  
Brain Lesions ◽  
Visual Feature ◽  
Feature Search ◽  
Dorsolateral Prefrontal

Deficits in visuospatial attention are commonly observed after different kinds of brain lesions. However, the structure–function relationships are not well understood. We investigated whether our response time (RT) model, strategies of visual search (STRAVIS), combined with a linear model of brain lesions, enables us to relate specific impairments in cognitive processes to specific sites of focal brain lesions. In STRAVIS, RTs in overt visual feature search with graded target-distractor similarity are decomposed into the durations of successive search steps. Fitting the model to an observer's RTs yields individual estimates of the parameters “attentional focus size,” “attentional dwell time,” and “movement time of attention or the eyes.” In 28 patients with various focal lesions to the frontal, parietal, and/or temporal cortex and 28 matched controls, we determined with the help of linear models which lesions were most predictive for each parameter. Predictions were validated with a second sample of 12 patients and 12 controls. Critical lesion areas for the STRAVIS focus size were the dorsolateral prefrontal cortex and the temporal lobe, with dorsolateral prefrontal cortex lesions reducing the focus and temporal lesions enlarging it. The STRAVIS dwell time was reduced in patients with lesions to the anterior insula and the superior parietal lobe. Lesions to the frontal eye fields, the superior parietal lobe, and the parieto-occipital cortex were most detrimental to the STRAVIS movement time. Applying linear models to a patient sample with heterogeneous lesions may be a promising new method for investigating how different brain areas interplay in a complex task.

An FMRI study of the dorsolateral prefrontal cortex activation during non-spatial verbal working memory tasks

1998 ◽  
Vol 31 ◽  
pp. S266
Author(s):  
Toshimitsu Takahashi ◽  
Ruiting Xiao ◽  
Masahiko Inase ◽  
Takashi Tsukiura ◽  
Kenji Kansaku ◽  
...  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Verbal Working Memory ◽  
Fmri Study ◽  
Dorsolateral Prefrontal

Reduced dorsolateral prefrontal cortex activation during affective Go/NoGo in violent schizophrenia patients: An fMRI study

2018 ◽  
Vol 197 ◽  
pp. 249-252 ◽  
Author(s):  
Andràs Tikàsz ◽  
Stéphane Potvin ◽  
Stéphane Richard-Devantoy ◽  
Olivier Lipp ◽  
Sheilagh Hodgins ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Fmri Study ◽  
Dorsolateral Prefrontal
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