In neuroscience, the default mode network (DMN), (also default network, or default state network), is a network of interacting brain regions known to have activity highly correlated with each other and distinct from other networks in the brain.
The default mode network is most commonly shown to be active when a person is not focused on the outside world and the brain is at wakeful rest, such as during daydreaming and mind-wandering. But it is also active when the individual is thinking about others, thinking about themselves, remembering the past, and planning for the future. The network activates "by default" when a person is not involved in a task. Though the DMN was originally noticed to be deactivated in certain goal-oriented tasks and is sometimes referred to as the task-negative network, it can be active in other goal-oriented tasks such as social working memory or autobiographical tasks. The DMN has been shown to be negatively correlated with other networks in the brain such as attention networks. Thinking about others also could include guessing their thoughts, emotions, and psychological motivations.
Evidence has pointed to disruptions in the DMN with people with Alzheimer’s and autism spectrum disorder.