|
In neuroscience, the default mode network (DMN), also called the default network or default state network, is a network of interacting brain regions that are known to be 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.〔 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.〔 Evidence has pointed to disruptions in the DMN with people with Alzheimer’s and Autism Spectrum Disorder.〔 == Function == The default mode network is known to be involved in many seemingly different functions: Information regarding the self: * ''Autobiographical information:'' Memories of collection of events and facts about one’s self * ''Self-reference:'' Referring to traits and descriptions of one’s self * ''Emotion of one’s self:'' Reflecting about one’s own emotional state Thinking about others:〔 * ''Theory of Mind:'' Thinking about the thoughts of others and what they might or might not know * ''Emotions of other:'' Understanding the emotions of other people and empathizing with their feelings * ''Moral reasoning:'' Determining just and unjust result of an action * ''Social evaluations:'' Good-bad attitude judgments about social concepts * ''Social categories:'' Reflecting on important social characteristics and status of a group Remembering that past and thinking about the future:〔 * ''Remembering the past:'' Recalling events that happened in the past * ''Imagining the future:'' Envisions events that might happen in the future * ''Episodic memory:'' Detailed memory related to specific event in time * ''Story comprehension:'' Understanding and remembering a narrative The default mode network is active during passive rest and mind-wandering.〔 Mind-wandering usually involves thinking about others, thinking about one’s self, remembering about the past, and envisioning the future.〔 Electrocorticography studies (which involve placing electrodes on the surface of epileptic patient’s brains) have shown the default mode network becomes activated within an order of a fraction of a second after participants finish a task. Studies have shown when people watch a movie, listen to a story or reading a story, their DMNs are highly correlated with each other. DMNs are not correlated if the stories are scrambled or in a language the person does not understand suggesting the network is highly involved comprehension and the subsequent memory formation of that story. The DMN is shown to even be correlated if the same story is presented to different people in different languages further suggesting the DMN is truly involved in the comprehension aspect of the story and not the auditory or language aspect. The default mode network is have shown to deactivate during external goal-oriented tasks such as visual attentions or cognitive working memory tasks thus leading some researchers to label the network as the task-negative network.〔 However, when the tasks are external goal-oriented tasks that are known to be a role of the DMN such as social working memory or an autobiographical task, the DMN is positively activated with the task and correlates with other networks such as the network involved in executive function.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Default mode network」の詳細全文を読む スポンサード リンク
|