Default mode network

The default mode network is the constellation of regions that increases its activity when attention turns inward and decreases it during externally focused, goal-directed tasks. It was first characterised from the consistent task-induced deactivations seen across positron emission tomography studies, and later confirmed as an intrinsically correlated network in resting-state functional MRI.

Its core nodes sit on the cortical midline, the medial prefrontal cortex and the posterior cingulate cortex with the adjacent precuneus, together with the bilateral angular gyri and portions of the medial temporal lobe. These regions support autobiographical memory, imagining the future, inferring the mental states of others, and self-referential processing.

Altered default mode connectivity is reported across several conditions, including Alzheimer’s disease, depression, and disorders of consciousness, which has made the network a frequent target in clinical neuroimaging research.