The Brain's Default Mode Network

The brain's default mode network consists of discrete, bilateral, and symmetrical cortical areas found in humans, nonhuman primates, cats, and rodents. It was discovered unexpectedly through PET imaging when novel, attention-demanding tasks were compared with quiet rest. This network consistently decreases its activity during such tasks relative to relaxed states. Its discovery renewed interest in the brain's ongoing or intrinsic activity, and resting-state studies now play a major role in understanding the human brain in health and disease, with the default mode network central to this work.

Study at a glance

Abstract

The brain's default mode network consists of discrete, bilateral and symmetrical cortical areas, in the medial and lateral parietal, medial prefrontal, and medial and lateral temporal cortices of the human, nonhuman primate, cat, and rodent brains. Its discovery was an unexpected consequence of brain-imaging studies first performed with positron emission tomography in which various novel, attention-demanding, and non-self-referential tasks were compared with quiet repose either with eyes closed or with simple visual fixation. The default mode network consistently decreases its activity when compared with activity during these relaxed nontask states. The discovery of the default mode network reignited a longstanding interest in the significance of the brain's ongoing or intrinsic activity. Presently, studies of the brain's intrinsic activity, popularly referred to as resting-state studies, have come to play a major role in studies of the human brain in health and disease. The brain's default mode network plays a central role in this work.