All parts of the brain › Networks › Default mode network

Where is the default mode network?

In several places at once: its core is the medial prefrontal cortex at the front, the posterior cingulate cortex and precuneus on the inner face toward the back, and the angular gyrus on the side, joined by the hippocampus, parahippocampal gyrus and lateral temporal cortex. [1]

Honest limit: networks are defined from brain imaging, and this atlas lights whole gyri, not the network’s exact borders. [2]

The 3D brain needs JavaScript. The list of parts still says what each one does for the default mode network.

Lit: whole parts; region borders not drawn.

Slice

All 7 parts are lit together. Drag to turn, pinch or scroll to zoom, tap a part on the brain or a name in the list to focus it; .

Medial prefrontal cortex is a region on the prefrontal cortex, not a separate shape. The 3D model has no shape for it, so the whole prefrontal cortex is lit; the region’s exact border is not drawn.

Posterior cingulate cortex is a region on the cingulate gyrus, not a separate shape. The 3D model has no shape for it, so the whole cingulate gyrus is lit; the region’s exact border is not drawn.

Precuneus is a region on the superior parietal lobule, not a separate shape. The 3D model has no shape for it, so the whole superior parietal lobule is lit; the region’s exact border is not drawn.

Default mode network: 7 parts lit

Prefrontal cortex, cingulate gyrus, superior parietal lobule, angular gyrus, hippocampus, parahippocampal gyrus and middle temporal gyrus. Tap one to see where it is and what it does.

The parts and their roles

Its medial part, the medial prefrontal cortex, is a core hub: it handles thinking about yourself (personal information, autobiographical memories), and its upper (dorsal) stretch is drawn on to infer the purpose of other people’s actions. [1] Where is the prefrontal cortex?
Holds the posterior cingulate cortex, the rear of the cingulate cortex and a central node of the network; with the precuneus it combines information from memory and perception with attention that is not under deliberate control. [3][1] Where is the cingulate gyrus?
Its inner face is the precuneus, the part of the superior parietal lobule on the medial surface of each hemisphere, proposed as a core hub of the network and linked to self-consciousness and to recalling episodic memories. [4] Where is the superior parietal lobule?
Connects perception, attention, spatial thinking and action, and helps recall episodes from memory. [1] Where is the angular gyrus?
Forms new memories, and is used both to remember the past and to imagine the future. [1] Where is the hippocampus?
Recognises and simulates places and scenes, which the network draws on when you picture a remembered or imagined setting. [1] Where is the parahippocampal gyrus?
Part of the lateral temporal cortex, which the network uses to retrieve social and conceptual knowledge; on its own the middle temporal gyrus is linked to accessing word meaning while reading and recognising known faces. [1][5] Where is the middle temporal gyrus?

Named areas on the lit gyri

Medial prefrontal cortex, on the : the inner face of the prefrontal cortex, one of the four regions the network is mainly made of. [1]
Posterior cingulate cortex, on the : the rear part of the cingulate cortex (Brodmann areas 23 and 31), the usual seed for finding the network in resting-state scans. [3][1]
Precuneus, on the : the medial part of the superior parietal lobule, bounded in front by the marginal branch of the cingulate sulcus and behind by the parieto-occipital sulcus. [4]

How they work together

It is most active when you are awake but not focused on the outside world: at rest, daydreaming and mind-wandering, thinking about other people, remembering the past and imagining the future; it builds the running internal narrative behind a sense of self. [1][2]
Marcus Raichle coined the term “default mode” in 2001 for the brain’s resting state; in 2003 Greicius and colleagues found the network in resting-state fMRI scans. Until the mid-2000s it was called the “task-negative network”, a label now considered misleading. [1]
It is found in two ways: by placing a seed in the posterior cingulate cortex in resting-state scans and mapping the regions whose activity moves with it, or as the areas that quieten during tasks aimed at the outside world compared with rest. [1]
Its activity tends to run opposite to attention networks: when a task pulls focus outward, the default mode network quietens, and the salience network is thought to switch the brain between it and the central executive network. [1][6]
There is no universal atlas of brain networks: which regions count and where their edges fall vary with the method and settings used and from person to person, and even the precuneus’s place in the network has been questioned. [2][4]

The salience network is the switch thought to move the brain out of default mode when something needs attention. [6] Where is the salience network?

Sources

Facts describe anatomy and normal function only. A part lit here takes part in the default mode network; it does not do it alone, and it does other jobs too. The 3D model is the adult male BodyParts3D brain (credits and licence); on it the brainstem includes the midbrain, pons and medulla, so lighting the brainstem lights all three.