Default mode network
As default mode network ( English , DMN, dt. Hibernation Network ) refers to a group of brain regions that when nothing is active and deactivated when solving tasks. The resting activity of these brain regions can be demonstrated with fMRI (especially Resting state fMRI ), PET , EEG and MEG .
The activity of these brain regions is correlated . Therefore this group of synchronously active brain regions is seen as a network . The network can be described with the mathematical tool graph theory . The brain regions involved include the medial prefrontal cortex , praecuneus , parts of the cingulate gyrus and - more weakly connected - the superior parietal lobule of the parietal lobe and the hippocampus .
The DMN becomes active (more) when a person is daydreaming , making plans for the future, etc. It enables so-called stimulus-independent thinking .
It could be shown that the anatomical and functional connectivity of the brain overlaps the most in the area of the default mode network . This was interpreted in such a way that the anatomical structure of the brain favors an activation of the network in states in which there is no task-specific requirement (in rest states).
discovery
The Default Mode Network was discovered in 2001 when neuroscientists compared the activated areas of the brain in a supposedly resting state with closed eyes or calmly fixed on a point with those that were activated while solving specific tasks. They found areas that were more active at rest than at concentration. After ruling out misrepresentations, they realized that the brain is exhibiting background activity that predominates when at rest but shuts down when focusing on specific functions.
Clinical relevance
Changes in the DMN have been found in some neurological and psychiatric diseases (including Alzheimer's disease , depression and schizophrenia ).
literature
- M. Pievani, W. de Haan, T. Wu, WW Seeley, GB Frisoni: Functional network disruption in the degenerative dementias. In: The Lancet Neurology . Volume 10, Number 9, September 2011, ISSN 1474-4465 , pp. 829-843, doi: 10.1016 / S1474-4422 (11) 70158-2 , PMID 21778116 (review).
- A. Otti, H. Gündel, A. Wohlschläger, C. Zimmer, C. Sorg, M. Noll-Hussong: "Default-mode" network of the brain. In: The neurologist . Volume 83, Number 1, January 2012, ISSN 1433-0407 , pp. 16-24, doi: 10.1007 / s00115-011-3307-6 , PMID 21584789 (review).
- Grodd, W. & Beckmann, C: Functional MRI of the brain at rest. In: Der Nervenarzt (2014) 85: 690. doi: 10.1007 / s00115-014-4013-y , PMID 24849117 .
- Grodd, W. & Beckmann, C: Chap. 15, Resting State fMRI. In: Frank Schneider, Gereon R. Fink (Ed.): Functional MRT in Psychiatry and Neurology, 2nd, revised and updated edition 2013, Springer-Verlag Berlin Heidelberg, ISBN 978-3-642-29799-1 , ISBN 978- 3-642-29800-4 (eBook), doi: 10.1007 / 978-3-642-29800-4
Web links
- Deutschlandfunk: What happens in the brain when daydreaming (October 2013)
- Spectrum of science: There is never peace in the head (June 2010, PDF available free of charge )
- Steve Ayan: The Benefits of Daydreaming , Brain & Mind, Issue 4/2016.
Videos
- Mind & Brain: The brain while doing nothing
Individual evidence
- ↑ A. Horn, D. Ostwald, M. Reisert, F. Blankenburg: The structural-functional connectome and the default mode network of the human brain . In: NeuroImage . 2013. doi : 10.1016 / j.neuroimage.2013.09.069 .
- ^ Marcus E. Raichle et al .: A default mode of brain function . In: PNAS, vol. 98 no. 2 (January 16, 2001), pp. 676-682