What is the default mode network?

What is the default mode network?

The default mode network is a group of brain regions that are more active when a person is resting quietly than when they are concentrating on a task. The name comes from a 2001 paper by Marcus Raichle and colleagues, who noticed something odd in brain imaging data: whenever volunteers did a demanding task, the same handful of regions reliably went quiet, and when the task stopped, they came back. Those regions were not idle at rest. They were busy with a baseline, or default, mode of brain function.

The core of the network is well agreed on. It includes the medial prefrontal cortex behind the forehead, the posterior cingulate cortex and precuneus in the midline toward the back of the brain, and the angular gyrus on each side where the parietal and temporal lobes meet. Parts of the lateral temporal cortex and the hippocampal formation, the brain's memory system, are also usually counted in.

The network is often described as sitting opposite the brain's attention systems. When you lock onto something outside you, the attention networks rise and the default network falls. When attention lets go, the pattern reverses. The two can work together, and the seesaw picture is a simplification, but it captures the main finding.

What does the default mode network do?

It handles the thinking you do when nothing outside demands your attention: remembering what happened, imagining what might happen, working out what other people are thinking, and considering yourself. Researchers group these under the heading of internal mentation, thought directed inward rather than at the world.

• Autobiographical memory. Replaying your own past, not as a list of facts but as scenes you were in.
• Prospection. Imagining the future: tomorrow's appointment, next summer, how a conversation might go.
• Thinking about other minds. Guessing what someone else believes, wants or feels.
• Self-referential thought. Judging whether a word describes you, weighing a decision against your values, noticing how you are doing.
• Mind-wandering. The drift that happens when a task is easy or boring and the mind goes somewhere else.

What these have in common is simulation. Each one builds a small internal scene with you in it, somewhere in time, and runs it. The network is, in effect, the brain's narrator. It takes the raw material of memory and pulls it into a story with a main character.

That is useful. A brain that can rehearse the future and learn from the past without acting anything out has an enormous advantage. The same machinery has a cost, which anyone who has lain awake at three in the morning already knows: the narrator does not stop when you would like it to, and it is not neutral about what it narrates.

How does the default mode network build a sense of self?

By telling the same story often enough that it feels like a fact. Psychologists distinguish two kinds of self. The experiencing self is whoever is present right now: the one noticing the chair, the light, the ache. The narrative self is the one with a biography: 'I am someone who used to run', 'I am the person who got hurt at work', 'I am not the kind of person who complains'. The default mode network is the system most consistently linked to the second kind.

The narrative self is a construction. There is no single place in the brain where a 'me' is stored. Instead, every time you remember, plan or reflect, the network assembles a version of you from stored memories and current expectations, and that assembled version feels continuous because the assembly is so fast and so practiced. This is the thread running through the whole of therapeutic neuroscience: the sense of self is built, moment by moment, from the same predictive machinery the brain uses for everything else.

Built does not mean fake. Your story about yourself is made from real events and real bodily signals, including what the body reports through interoception. But a story is a selection, and the selection can be revised. That is the difference between a self that is fixed and a self that is merely stable. Our guide to the sense of self in chronic pain goes deeper into how the construction works and what happens when it organizes around threat.

What happens to the default mode network in chronic pain?

It appears to behave differently, in ways that line up with what people in chronic pain describe. The key word is 'appears', and we will come back to it.

The study that started this line of work was published in 2008 by Marwan Baliki, Vania Apkarian and colleagues. They asked a small group of people with chronic low back pain and a matched group without pain to do a visual attention task in the scanner. In the pain-free group, the default mode network quietened as expected when the task began. In the chronic pain group, parts of it did not: the medial prefrontal cortex and nearby regions stayed active while the task ran. The network was failing to step aside when attention was needed elsewhere, as if the narrator kept talking over the work.

Later research broadened the picture. A 2015 review by Aaron Kucyi and Karen Davis described what they called the dynamic pain connectome: pain is not produced by one fixed set of regions but by shifting communication between the default mode network, the salience network that flags what matters, and the brainstem systems that can turn pain down. In healthy volunteers, the ability to mind-wander away from a painful stimulus tracked with coupling between the default network and one of those pain-dampening brainstem regions. In people with chronic pain, by contrast, the default network showed closer coupling with the insula, a region central to how the body feels from the inside, and the strength of that coupling tracked with how much the person ruminated about their pain.

Why rumination matters here

Rumination, magnification and helplessness are the three parts of pain catastrophizing, and together they are what the Pain Catastrophizing Scale measures. All three are self-referential, future-oriented thought: 'I can't stop thinking about it', 'it's going to get worse', 'there is nothing I can do'. That is the default network's home ground. If the narrator spends its idle time running those scenes, the self it assembles is a self organized around a damaged body, and the brain's predictions about that body shift to match. Our guide to predictive coding explains why predictions of threat tend to produce more pain, and how, in chronic pain, a protective inference can keep firing after the tissue has healed.

What these studies cannot tell us

Every finding above is correlational. The imaging studies compare groups at one moment, and they cannot say whether altered network activity causes chronic pain, follows from it, or shares a common cause with it. Living with pain for years is enough on its own to change what a person thinks about when their mind is free. The samples are small, the methods vary between studies, and the headline that chronic pain 'hurts the brain' goes beyond what the data show. What the research does establish is a consistent pattern: in chronic pain, the brain's self-narrating system is more entangled with its threat and body-sensing systems than it is in people without pain.

Can the default mode network change?

Its activity and connectivity differ with experience, which is a form of yes. The brain reorganizes in response to what it repeatedly does, the general principle described on our neuroplasticity page, and the default network is no exception.

The best-known evidence comes from meditation. In a 2011 study, Judson Brewer and colleagues scanned experienced meditators and matched novices during several kinds of meditation. The experienced group showed less activity in the two main hubs of the default network, the medial prefrontal and posterior cingulate cortices, and stronger connections between the posterior cingulate and regions involved in monitoring and control. The difference held both during meditation and at rest, which suggests a trait rather than a momentary state. The study is cross-sectional, so it shows that experienced meditators differ from novices, not that meditation caused the difference. Still, it is consistent with a network that attention training can shape.

Attention-based approaches to pain work along the same lines. Mindfulness training, body awareness practices and the attention work inside pain reprocessing therapy all ask the person to return, over and over, from the narrated body to the sensed one. In the terms of this page, they practice letting the experiencing self take the microphone from the narrator. The evidence that these approaches reduce pain is real but mixed in size, and the evidence that they do it through the default network specifically is thinner still.

Changing the story with first-person evidence

A narrator can be argued with, but narrators are more persuaded by what they witness. This is the thinking behind embodied approaches. In virtual embodiment therapy, a person sees a virtual body from their own point of view that moves when they move, and the brain tends to adopt it as its own. If that body is seen moving the painful region smoothly and safely, the brain receives direct, first-person evidence that contradicts the story 'this part of me is broken'. One exposure does little. Repeated over weeks, the aim is to give the self-model so many safe experiences of movement that the prediction of threat loses its grip. The lab evidence on virtual embodiment and pain is early and promising rather than settled.

Karuna's program, Karuna Virtual Embodiment Training (KVET)™, is built on this idea. Over 12 weeks at home, on a provided headset, patients do short daily VR embodiment exercises designed to create safe prediction errors around movement and to retrain the brain's map of the body. A weekly one-on-one session with a pain coach puts the in-headset experience into words and into daily life, and a clinician reviews each case before the start and oversees the course. Karuna has published uncontrolled outcome data from its program; the figures, and the limits on what they can show, are on the how it works page.

What does this mean if you have chronic pain?

First, that the pain is real. Nothing on this page says otherwise. The default mode network findings describe how a brain in long-term pain spends its idle time, and they would be surprising only if a brain in pain did not think about pain. Tissue, nerves and disease are real inputs, and pain that has not been medically assessed needs assessment before anything else.

Second, that the story you tell about your body is part of the system that produces the pain, and it is a part you can work on. Not by arguing with yourself, which the narrator tends to win, but by noticing the difference between the sensation and the story, and by giving the brain new first-person experiences that the story has to account for. This is what therapeutic neuroscience means in practice: education changes what the pain means, attention changes which signals get weight, and graded, embodied movement changes what the body is predicted to be able to do.

Third, that progress is often uneven. The narrator has had years of practice telling one story. Many people who work this way improve substantially in function and in pain; others improve less or not at all, and no one can tell you in advance which group you will be in. Changes in confidence and movement usually show up before changes in pain.

For clinicians

The default mode network literature is a reason to measure catastrophizing and rumination alongside pain intensity, and to treat them as targets rather than character traits. It also argues for approaches that supply disconfirming experience alongside disconfirming information: graded exposure, sensorimotor retraining and embodied practice. The Lancet review of nociplastic pain and the commentary on graded sensorimotor retraining are useful companions.

If your pain has been medically evaluated and persists, Karuna offers a free consultation to talk through whether the program fits. The program is HSA/FSA eligible and backed by a money-back guarantee. Karuna also takes workers' compensation referrals, and the care team confirms coverage case by case.