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On the existence of a generalized non-specific task-dependent network.

Hugdahl K, Raichle ME, Mitra A, Specht K - Front Hum Neurosci (2015)

Bottom Line: We now suggest that this is because the brain utilizes the EMN network as a generalized response to tasks that exceeds a cognitive demand threshold and/or requires the processing of novel information.We further discuss how the EMN is related to the DMN, and how a network for extrinsic activity is related to a network for intrinsic activity.Finally, we discuss whether the EMN and DMN networks interact in a common single brain system, rather than being two separate and independent brain systems.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway ; Division of Psychiatry, Haukeland University Hospital, Bergen Norway ; Department of Radiology, Haukeland University Hospital, Bergen Norway ; NORMENT Center of Excellence, University of Bergen Bergen, Norway.

ABSTRACT
In this paper we suggest the existence of a generalized task-related cortical network that is up-regulated whenever the task to be performed requires the allocation of generalized non-specific cognitive resources, independent of the specifics of the task to be performed. We have labeled this general purpose network, the extrinsic mode network (EMN) as complementary to the default mode network (DMN), such that the EMN is down-regulated during periods of task-absence, when the DMN is up-regulated, and vice versa. We conceptualize the EMN as a cortical network for extrinsic neuronal activity, similar to the DMN as being a cortical network for intrinsic neuronal activity. The EMN has essentially a fronto-temporo-parietal spatial distribution, including the inferior and middle frontal gyri, inferior parietal lobule, supplementary motor area, inferior temporal gyrus. We hypothesize that this network is always active regardless of the cognitive task being performed. We further suggest that failure of network up- and down-regulation dynamics may provide neuronal underpinnings for cognitive impairments seen in many mental disorders, such as, e.g., schizophrenia. We start by describing a common observation in functional imaging, the close overlap in fronto-parietal activations in healthy individuals to tasks that denote very different cognitive processes. We now suggest that this is because the brain utilizes the EMN network as a generalized response to tasks that exceeds a cognitive demand threshold and/or requires the processing of novel information. We further discuss how the EMN is related to the DMN, and how a network for extrinsic activity is related to a network for intrinsic activity. Finally, we discuss whether the EMN and DMN networks interact in a common single brain system, rather than being two separate and independent brain systems.

No MeSH data available.


Related in: MedlinePlus

BOLD-functional magnetic resonance imaging (fMRI) activations from nine different cognitive studies by the Bergen fMRI Group (panels #1–9), with nine different cognitive tasks, visualized on standard SPM templates. There were different subject groups in the nine different studies.
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Figure 1: BOLD-functional magnetic resonance imaging (fMRI) activations from nine different cognitive studies by the Bergen fMRI Group (panels #1–9), with nine different cognitive tasks, visualized on standard SPM templates. There were different subject groups in the nine different studies.

Mentions: The origin of this paper was an incidental observation when preparing for a lecture by one of the authors (KH), that when comparing brain activation patterns from functional magnetic resonance imaging (fMRI) data across different studies done in our laboratory at the Bergen fMRI Group, University of Bergen, Norway over the last 10–15 years, a common pattern of activation emerged despite that these studies had used different cognitive stimulus paradigms and tasks. This is shown in Figure 1.


On the existence of a generalized non-specific task-dependent network.

Hugdahl K, Raichle ME, Mitra A, Specht K - Front Hum Neurosci (2015)

BOLD-functional magnetic resonance imaging (fMRI) activations from nine different cognitive studies by the Bergen fMRI Group (panels #1–9), with nine different cognitive tasks, visualized on standard SPM templates. There were different subject groups in the nine different studies.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526816&req=5

Figure 1: BOLD-functional magnetic resonance imaging (fMRI) activations from nine different cognitive studies by the Bergen fMRI Group (panels #1–9), with nine different cognitive tasks, visualized on standard SPM templates. There were different subject groups in the nine different studies.
Mentions: The origin of this paper was an incidental observation when preparing for a lecture by one of the authors (KH), that when comparing brain activation patterns from functional magnetic resonance imaging (fMRI) data across different studies done in our laboratory at the Bergen fMRI Group, University of Bergen, Norway over the last 10–15 years, a common pattern of activation emerged despite that these studies had used different cognitive stimulus paradigms and tasks. This is shown in Figure 1.

Bottom Line: We now suggest that this is because the brain utilizes the EMN network as a generalized response to tasks that exceeds a cognitive demand threshold and/or requires the processing of novel information.We further discuss how the EMN is related to the DMN, and how a network for extrinsic activity is related to a network for intrinsic activity.Finally, we discuss whether the EMN and DMN networks interact in a common single brain system, rather than being two separate and independent brain systems.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway ; Division of Psychiatry, Haukeland University Hospital, Bergen Norway ; Department of Radiology, Haukeland University Hospital, Bergen Norway ; NORMENT Center of Excellence, University of Bergen Bergen, Norway.

ABSTRACT
In this paper we suggest the existence of a generalized task-related cortical network that is up-regulated whenever the task to be performed requires the allocation of generalized non-specific cognitive resources, independent of the specifics of the task to be performed. We have labeled this general purpose network, the extrinsic mode network (EMN) as complementary to the default mode network (DMN), such that the EMN is down-regulated during periods of task-absence, when the DMN is up-regulated, and vice versa. We conceptualize the EMN as a cortical network for extrinsic neuronal activity, similar to the DMN as being a cortical network for intrinsic neuronal activity. The EMN has essentially a fronto-temporo-parietal spatial distribution, including the inferior and middle frontal gyri, inferior parietal lobule, supplementary motor area, inferior temporal gyrus. We hypothesize that this network is always active regardless of the cognitive task being performed. We further suggest that failure of network up- and down-regulation dynamics may provide neuronal underpinnings for cognitive impairments seen in many mental disorders, such as, e.g., schizophrenia. We start by describing a common observation in functional imaging, the close overlap in fronto-parietal activations in healthy individuals to tasks that denote very different cognitive processes. We now suggest that this is because the brain utilizes the EMN network as a generalized response to tasks that exceeds a cognitive demand threshold and/or requires the processing of novel information. We further discuss how the EMN is related to the DMN, and how a network for extrinsic activity is related to a network for intrinsic activity. Finally, we discuss whether the EMN and DMN networks interact in a common single brain system, rather than being two separate and independent brain systems.

No MeSH data available.


Related in: MedlinePlus