Our brains are amazing things. There’s still so much unknown about this incredible organ, but all around the world scientists are hard at work every day trying to unlock its secrets and help us better understand how it functions.

There’s decades worth of research about the way the brain behaves when we’re engaged in different activities where we are focused and attentive on some task or external stimuli, but more recent studies have shown that certain regions of our brain are active even at times of rest.

This type of cognitive function consists of a large group of interconnected brain regions known as the “default mode network”, discovered by neurologist Marcus Raichle. Research has shown that these regions are typically active when a person is not engaged in a specific task.

The anatomy of it is fascinating; the active regions can be broken down into several hubs and subsections, including functional hubs that relate to information stored about oneself including the Posterior cingulate cortex and Medial prefrontal cortex. Also connected are subsections that relate to thinking about others such as the Dorsal medial prefrontal cortex, and medial temporal subsystems relating to memory and future simulations, all connected by white matter tracts as show in imaging from MRIs.

To better explain when the DMN is active, consider it as the parts of your brain that fire when you’re daydreaming, when your mind is wandering, or when you’re engaged in introspective thought. It plays a role in things like memory retrieval, self-reflection, thinking about others, and envisioning the future.

When you become focused on a task or some kind of external stimuli, that’s when the DMN deactivates. However, electrocorticography studies have shown that it can activate again within a fraction of a second after a task has been completed. There’s a reason for its name – it refers to when you are in your “default” state.

Disruption of the DMN has been linked to several psychiatric and neurological disorders, including Alzheimer’s disease, autism, schizophrenia, and PTSD. Conversely, studies have shown the DMN to be hyperactive in people with major depressive disorder by changing the way a person perceives events and making them more susceptible to depressive symptoms.

Abnormalities in the DMN can be modulated in a number of different ways, including antidepressants, physical exercise, and meditation.

I was introduced to the concept of the DMN through my meditation practice. Meditation, mindfulness, and other relaxation techniques can calm an overactive DMN. As someone fairly new to the practice of meditation, I am still learning how to control this. My mind often wanders during meditation, which is not a failure of the practice by any means; it just means my DMN is firing. When I notice this, I am able to pull my focus back into the task at hand, which is achieving mindfulness. Meditation experts are much more adept at quieting this network, and as I continue to improve in my practice, I will be as well.

So next time you feel yourself drifting away in thought, just know this is a highly sophisticated network of brain regions at work. If this is something you feel you want to learn to better control, I highly suggest the Healthy Minds Program app. This app is excellent for beginners to the practice of meditation, offering insightful lessons and guided meditations to help you toward the path of awareness. There is even a session dedicated to better understanding the default mode network and its role in our every day lives.