Functional Disconnection Between the Prefrontal and Parietal Cortices During Working Memory Processing in Schizophrenia: A [<sup>15</sup>O]H<sub>2</sub>O PET Study

Kim, Jae‐Jin; Kwon, Jun Soo; Park, Hae Jeong; Youn, Tae Jin; Kang, Do Hyung; Kim, Myung Sun; Lee, Dong Hoon; Lee, Myung Chul

doi:10.1176/appi.ajp.160.5.919

Cited by 137 publications

(80 citation statements)

References 26 publications

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“…The schizophrenia subjects in previous studies showing VLPFC overactivation also exhibited hypoactivation of DLPFC, leading some investigators to suggest a compensatory role for the VLPFC (Andreasen et al, 1997;Kim et al, 2003;Tan et al, 2005). Our connectivityperformance analysis does not support the idea that increased temporal-VLPFC connectivity is an effective compensatory mechanism, as there was no correlation with performance in either group.…”

Section: Discussioncontrasting

confidence: 86%

“…We are not aware of any studies reporting increased temporal-VLPFC connectivity, although it occurred at subthreshold levels in one study described above (Meyer-Lindenberg et al, 2005, supplementary online data). While both groups in the current study activated VLPFC equally (Ragland et al, 2005), as in Jennings et al (1998) and Barch et al (2001), other studies have found increased task-related activity of VLPFC in schizophrenia (Kim et al, 2003;Bonner-Jackson et al, 2005;Tan et al, 2005). Overactivation of left inferior frontal cortex has also been observed in a resting PET study (Andreasen et al, 1997), and intriguingly, treatment with either haldoperidol or clozapine reduced VLPFC activity (Lahti et al, 2003).…”

Section: Discussionsupporting

confidence: 51%

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Alterations of fronto-temporal connectivity during word encoding in schizophrenia

Wolf

Gur

Valdez

et al. 2007

Psychiatry Research: Neuroimaging

106

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Cognitive deficits, including impaired verbal memory, are prominent in schizophrenia and lead to increased disability. Functional neuroimaging of patients with schizophrenia performing memory tasks has revealed abnormal activation patterns in prefrontal cortex and temporo-limbic regions. Aberrant fronto-temporal interactions thus represent a potential pathophysiological mechanism underlying verbal memory deficits, yet this hypothesis of disturbed connectivity is not tested directly with standard activation studies. We performed within-subject correlations of frontal and temporal timeseries to measure functional connectivity during verbal encoding. Our results confirm earlier findings of aberrant fronto-temporal connectivity in schizophrenia, and extend them by identifying distinct alterations within dorsal and ventral prefrontal cortex. Relative to healthy controls, patients with schizophrenia had reduced connectivity between the dorsolateral prefrontal cortex (DLPFC) and temporal lobe areas including parahippocampus and superior temporal gyrus. In contrast, patients showed increased connectivity between a region of ventrolateral prefrontal cortex (VLPFC) and these same temporal lobe regions. Higher temporal-DLPFC connectivity during encoding was associated with better subsequent recognition accuracy in controls, but not patients. Temporal-VLPFC connectivity was uncorrelated with recognition accuracy in either group. The results suggest that reduced temporal-DLPFC connectivity in schizophrenia could underlie encoding deficits, and increased temporal-VLPFC connectivity may represent an ineffective compensatory effort.

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Section: Discussioncontrasting

confidence: 86%

Section: Discussionsupporting

confidence: 51%

Alterations of fronto-temporal connectivity during word encoding in schizophrenia

Wolf

Gur

Valdez

et al. 2007

Psychiatry Research: Neuroimaging

106

View full text Add to dashboard Cite

show abstract

“…For the 2-back task, we found % CBF changes ranging from 10 to 26% (7-11 ml/100 g/min). Some PET studies reported 2-7% CBF changes for the 2-back condition compared to the 0-back control (e.g., Jonides et al, 1997;Kim et al, 2003). However, % CBF changes are likely to be influenced by many factors such as the nature of the control condition, the sizes of smoothing kernels and ROIs and whether normalization was done or not.…”

Section: Discussionmentioning

confidence: 99%

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

et al. 2006

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Arterial spin labeling (ASL) perfusion fMRI is an emerging method in clinical neuroimaging. Its non-invasiveness, absence of low frequency noise, and ability to quantify the absolute level of cerebral blood flow (CBF) make the method ideal for longitudinal designs or low frequency paradigms. Despite the usefulness in the study of cognitive dysfunctions in clinical populations, perfusion activation studies to date have been conducted for simple sensorimotor paradigms or with single-slice acquisition, mainly due to technical challenges. Using our recently developed amplitudemodulated continuous ASL (CASL) perfusion fMRI protocol, we assessed the feasibility of a higher level cognitive activation study in twelve healthy subjects. Taking advantage of the ASL noise properties, we were able to study tonic CBF changes during uninterrupted 6-min continuous performance of working memory and sustained attention tasks. For the visual sustained attention task, regional CBF increases (6-12 ml/100 g/min) were detected in the right middle frontal gyrus, the bilateral occipital gyri, and the anterior cingulate/medial frontal gyri. During the 2-back working memory task, significantly increased activations (7-11 ml/100 g/min) were found in the left inferior frontal/precentral gyri, the left inferior parietal lobule, the anterior cingulate/medial frontal gyri, and the left occipital gyrus. Locations of activated and deactivated areas largely concur with previous PET and BOLD fMRI studies utilizing similar paradigms. These results demonstrate that CASL perfusion fMRI can be successfully utilized for the investigation of the tonic CBF changes associated with high level cognitive operations. Increased applications of the method to the investigation of cognitively impaired populations are expected to follow.

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“…In this regard, several studies of schizophrenia (SCH) are based on the hypothesis that this pathology produces a disruption on the synaptic efficacy [1], which results on functional disconnection during working memory processing [2]. Although, previous studies suggest that SCH is accompanied by a reorganization deficit of the brain network during the performance of a simple cognitive task, such as an auditory * * This research was supported in part by the projects TEC2014-53196-R of 'Ministerio de Economía y Competitividad' and FEDER, and the project VA059U13 of "Consejería de Educación".…”

Section: Introductionmentioning

confidence: 99%

Novel measure of the weigh distribution balance on the brain network: Graph complexity applied to schizophrenia

Gómez‐Pilar

Poza

Bachiller

et al. 2016

2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

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Abstract-The aim of this study was to assess brain complexity dynamics in schizophrenia (SCH) patients during an auditory oddball task. For that task, we applied a novel graph measure based on the balance of the node weighs distribution. Previous studies applied complexity parameters that were strongly dependent on network topology. This fact could bias the results besides being necessary correction techniques as surrogating process. In the present study, we applied a novel graph complexity measure from the information theory: Shannon Graph Complexity (SGC). Complexity patterns form electroencephalographic recordings of 20 healthy controls and 20 SCH patients during an auditory oddball task were analyzed. Results showed a significantly more pronounced decrease of SGC for controls than for SCH patients during the cognitive task. These findings suggest an important change in the brain configuration towards more balanced networks, mainly in the connections related to longrange interactions. Since these changes are significantly more pronounced in controls, it implies a deficit in the neural network reorganization in SCH patients. In addition, SGC showed a suitable discrimination ability using a leave-one-out cross-validation: 0.725 accuracy and 0.752 area under receiver operating characteristics curve. The novel complexity measure proposed in this study demonstrated to be independent of network topology and, therefore, it complements traditional graph measures to characterize brain networks.

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Functional Disconnection Between the Prefrontal and Parietal Cortices During Working Memory Processing in Schizophrenia: A [¹⁵O]H₂O PET Study

Abstract: The findings suggest prefrontal-parietal functional disconnection, particularly prefrontal dissociation and abnormal prefrontal-parietal interaction, during working memory processing in schizophrenia.

Cited by 137 publications

References 26 publications

Alterations of fronto-temporal connectivity during word encoding in schizophrenia

Alterations of fronto-temporal connectivity during word encoding in schizophrenia

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

Novel measure of the weigh distribution balance on the brain network: Graph complexity applied to schizophrenia

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Functional Disconnection Between the Prefrontal and Parietal Cortices During Working Memory Processing in Schizophrenia: A [15O]H2O PET Study

Abstract: The findings suggest prefrontal-parietal functional disconnection, particularly prefrontal dissociation and abnormal prefrontal-parietal interaction, during working memory processing in schizophrenia.

Cited by 137 publications

References 26 publications

Alterations of fronto-temporal connectivity during word encoding in schizophrenia

Alterations of fronto-temporal connectivity during word encoding in schizophrenia

Continuous ASL perfusion fMRI investigation of higher cognition: Quantification of tonic CBF changes during sustained attention and working memory tasks

Novel measure of the weigh distribution balance on the brain network: Graph complexity applied to schizophrenia

Contact Info

Product

Resources

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Functional Disconnection Between the Prefrontal and Parietal Cortices During Working Memory Processing in Schizophrenia: A [¹⁵O]H₂O PET Study