Task-positive network

The task-positive network is a network of areas in the human brain that typically responds with activation increases to attention-demanding tasks in functional imaging studies.[1] The task-positive network encompasses regions of the dorsal attention system, but in addition includes dorsolateral and ventrolateral prefrontal regions, the insular cortex, and the supplementary motor area.[1] Recent work indicates that the cerebellum may participate in this network as well.[2][3] Notably, the nodes of this network are also correlated during rest (i.e., in the absence of any task).[1] The task-positive network is anti-correlated with the default mode network.[1][4] Competing activation between the task-positive network and the default mode network at the time of memory encoding has been shown to result in poor long-term memory consolidation.[5]

During rest the task-positive network has been claimed to subserve intermittent "external awareness", defined as the conscious perception through different sensory modalities of one's surrounding environment.[6]

Function

During performance of attention-demanding tasks, prefrontal and parietal structures that comprise the task-positive network are characterized by increases in activation; in contrast, default mode network structures, including posterior cingulate and medial prefrontal cortices, are characterized by decreased activity. During wakeful rest, the opposite pattern emerges, with the default mode network becoming more active and the task-positive network less active.[7]

References
  1. Fox, M. D.; Snyder, A. Z.; Vincent, J. L.; Corbetta, M.; Van Essen, D. C.; Raichle, M. E. (2005). "From The Cover: The human brain is intrinsically organized into dynamic, anticorrelated functional networks". Proceedings of the National Academy of Sciences. 102 (27): 9673–9678. doi:10.1073/pnas.0504136102. ISSN 0027-8424. PMC 1157105. PMID 15976020.
  2. Somers, David C.; Halko, Mark A.; Levin, Emily J.; Osher, David E.; Tobyne, Sean M.; Brissenden, James A. (2018-11-05). "Topographic Cortico-cerebellar Networks Revealed by Visual Attention and Working Memory". Current Biology. 28 (21): 3364–3372.e5. doi:10.1016/j.cub.2018.08.059. ISSN 0960-9822. PMC 6257946. PMID 30344119.
  3. Somers, David C.; Halko, Mark A.; Osher, David E.; Levin, Emily J.; Brissenden, James A. (2016-06-01). "Functional Evidence for a Cerebellar Node of the Dorsal Attention Network". Journal of Neuroscience. 36 (22): 6083–6096. doi:10.1523/JNEUROSCI.0344-16.2016. ISSN 0270-6474. PMC 4887569. PMID 27251628.
  4. Fransson, P. (2005). "Spontaneous low-frequency BOLD signal fluctuations: an fMRI investigation of the resting-state default mode of brain function hypothesis". Human Brain Mapping. 26 (1): 15–29. doi:10.1002/hbm.20113. PMID 15852468.
  5. Lefebvre, Etienne; D’Angiulli, Amedeo (2019). "Imagery-Mediated Verbal Learning Depends on Vividness–Familiarity Interactions: The Possible Role of Dualistic Resting State Network Activity Interference". Brain Sciences. 9 (6): 143. doi:10.3390/brainsci9060143. ISSN 2076-3425. PMC 6627679. PMID 31216699.
  6. Vanhaudenhuyse, Audrey; Demertzi, Athena; Schabus, Manuel; Noirhomme, Quentin; Bredart, Serge; Boly, Melanie; Phillips, Christophe; Soddu, Andrea; Luxen, Andre; Moonen, Gustave; Laureys, Steven (1 March 2011). "Two Distinct Neuronal Networks Mediate the Awareness of Environment and of Self". Journal of Cognitive Neuroscience. 23 (3): 570–578. doi:10.1162/jocn.2010.21488. PMID 20515407.
  7. Hamilton, J.Paul (2011). "Default-Mode and Task-Positive Network Activity in Major Depressive Disorder: Implications for Adaptive and Maladaptive Rumination" (PDF). Biological Psychiatry. 70 (4): 327–333. doi:10.1016/j.biopsych.2011.02.003. PMC 3144981. PMID 21459364. Retrieved 6 June 2014.
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