Article

Competition between functional brain networks mediates behavioral variability. Neuroimage, 39(1), 527-537

NYU Langone Medical Center, New York, New York, United States
NeuroImage (Impact Factor: 6.36). 02/2008; 39(1):527-37. DOI: 10.1016/j.neuroimage.2007.08.008
Source: PubMed

ABSTRACT Increased intraindividual variability (IIV) is a hallmark of disorders of attention. Recent work has linked these disorders to abnormalities in a "default mode" network, comprising brain regions routinely deactivated during goal-directed cognitive tasks. Findings from a study of the neural basis of attentional lapses suggest that a competitive relationship between the "task-negative" default mode network and regions of a "task-positive" attentional network is a potential locus of dysfunction in individuals with increased IIV. Resting state studies have shown that this competitive relationship is intrinsically represented in the brain, in the form of a negative correlation or antiphase relationship between spontaneous activity occurring in the two networks. We quantified the negative correlation between these two networks in 26 subjects, during active (Eriksen flanker task) and resting state scans. We hypothesized that the strength of the negative correlation is an index of the degree of regulation of activity in the default mode and task-positive networks and would be positively related to consistent behavioral performance. We found that the strength of the correlation between the two networks varies across individuals. These individual differences appear to be behaviorally relevant, as interindividual variation in the strength of the correlation was significantly related to individual differences in response time variability: the stronger the negative correlation (i.e., the closer to 180 degrees antiphase), the less variable the behavioral performance. This relationship was moderately consistent across resting and task conditions, suggesting that the measure indexes moderately stable individual differences in the integrity of functional brain networks. We discuss the implications of these findings for our understanding of the behavioral significance of spontaneous brain activity, in both healthy and clinical populations.

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    NeuroImage 07/2015; DOI:10.1016/j.neuroimage.2015.07.041 · 6.36 Impact Factor
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    • "Previous studies have suggested that these two networks comprise a competing brain system that regulates and sustains essential brain functions (Fox et al., 2005; Vincent et al., 2008). Greater anti-correlation between the DMN and the task-positive attention network has been associated with more reliable behavioral performance (Kelly et al., 2008), while failure to suppress DMN activity during tasks has been associated with attention lapses (Weissman et al., 2006). Our findings are consistent with these studies and support the important role of both taskpositive and task-negative networks in TOT effects. "
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    NeuroImage 07/2015; DOI:10.1016/j.neuroimage.2015.07.030 · 6.36 Impact Factor
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