Large scale brain networks

Large scale brain networks are collections of widespread brain regions with functional connectivity, driven by synchronized signal fluctuations^[1] and measured primarily by fMRI. Long-range synchronizations can also be identified by EEG, MEG, and other techniques.^[2] The synchronized brain regions are determined statistically using spatial independent component analysis adapted to resting state fMRI. As a result, the set of identified networks varies from study to study. Large scale brain networks are conceptually equivalent to resting state networks (RSN), but networks are identified by their function, as opposed to the brain regions where the RSN is localized. Large-scale brain networks provide a coherent framework for understanding of cognition^[2] by providing a model of how different brain regions form coalitions.

Networks

An fMRI scan shows 10 large scale brain networks.

The following four networks have been identified by at least three studies.

• Default mode: active during introspection.^{[1][2][3][4][5]}

• Dorsal attention: voluntary deployment of attention and reorientation to unexpected events.^[1][3][4][6]

• Salience: monitors the salience of external inputs and internal brain events.^[1][2][3][5]

• Lateral visual: important in complex emotional stimuli.^[3][4][5]

Several other brain networks have also been identified: auditory,^[3][5] motor,^[3] right executive,^[3][5] posterior default mode,^[3] left fronto-parietal,^[4] cerebellar,^[4][5] ventral attention,^[4][6] spatial attention,^[1][2] language,^[2] left executive,^[5] sensorimotor,^[5] and the "Christmas Spirit" network.^[7]

References