Cortical networks for working memory and executive function sustain the conscious resting state in man

Groupe d'Imagerie Neurofonctionnelle, UMR6095, CNRS, LEA, Université de Caen, Université 5, Paris, France.
Brain Research Bulletin (Impact Factor: 2.72). 03/2001; 54(3):287-98. DOI: 10.1016/S0361-9230(00)00437-8
Source: PubMed

ABSTRACT The cortical anatomy of the conscious resting state (REST) was investigated using a meta-analysis of nine positron emission tomography (PET) activation protocols that dealt with different cognitive tasks but shared REST as a common control state. During REST, subjects were in darkness and silence, and were instructed to relax, refrain from moving, and avoid systematic thoughts. Each protocol contrasted REST to a different cognitive task consisting either of language, mental imagery, mental calculation, reasoning, finger movement, or spatial working memory, using either auditory, visual or no stimulus delivery, and requiring either vocal, motor or no output. A total of 63 subjects and 370 spatially normalized PET scans were entered in the meta-analysis. Conjunction analysis revealed a network of brain areas jointly activated during conscious REST as compared to the nine cognitive tasks, including the bilateral angular gyrus, the left anterior precuneus and posterior cingulate cortex, the left medial frontal and anterior cingulate cortex, the left superior and medial frontal sulcus, and the left inferior frontal cortex. These results suggest that brain activity during conscious REST is sustained by a large scale network of heteromodal associative parietal and frontal cortical areas, that can be further hierarchically organized in an episodic working memory parieto-frontal network, driven in part by emotions, working under the supervision of an executive left prefrontal network.

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Available from: Laurent Petit, Sep 26, 2015
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    • "This pattern was consistent with that in previous studies which showed high ReHo (Long et al., 2008), ALFF and fALFF (Zang et al., 2007; Zou et al., 2008; Zuo et al., 2010) within the DMN. Previous studies have consistently demonstrated that the DMN regions show task-independent deactivation across a wide range of cognitive tasks compared with the resting-state (Shulman et al., 1997; Binder et al., 1999; Mazoyer et al., 2001), and these areas had signifi cantly higher blood fl ow and oxygen consumption than the global mean value (Raichle et al., 2001). The current results that DMN showed high activity is consistent with the conclusion that these regions represent the functional core underlying resting brain dynamics (Ghosh et al., 2008; Honey et al., 2009; Zuo et al., 2010). "
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    • "Positron emission tomography (PET) first demonstrated that a set of brain regions including posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC), thalamus and insula exhibit higher cerebral blood flow (CBF) than the whole brain average in the resting state (Raichle et al., 2001). CBF in the majority of these regions decreases from its baseline level during a wide range of goal-directed tasks (Shulman et al., 1997; Mazoyer et al., 2001). Together, these brain regions have been called the default mode network (DMN). "
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    • "Finally, math judgments were entirely nonsocial and asked participants to evaluate arithmetical expressions. Mental arithmetic is a cognitive task known to reliably suppress activity in the DMN (Mazoyer et al., 2001) and would thus provide a method for independently defining regions demonstrating high activity during the fixation baseline period that preceded each judgment. The mind-focused and body-focused conditions featured 40 naturalistic photographs of people performing goal-directed actions and/or displaying expressions of emotion. "
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