Dorsal attention network
The task-positive network (TPN) 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 SMA/pre-SMA.[1] 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 task-negative network.[1] [2]
During rest the TPN has been claimed to subserve intermittent “external awareness”, defined as the conscious perception through different sensory modalities of one's surrounding environment.[3]
Function
During performance of attention-demanding tasks, prefrontal and parietal structures comprising 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. [4]
References
- ^ a b c d 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.
- ^ 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.
- ^ 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.
- ^ Hamilton, J.Paul (2011). "Default-Mode and Task-Positive Network Activity in Major Depressive Disorder: Implications for Adaptive and Maladaptive Rumination" (PDF). Biological Psychiatry, Society of Biological Psychiatry. 70: 327–333. Retrieved 6 June 2014.