Why Can’t I Stop Worrying?

The answer may be in the Default Mode Network.

Posted Aug 31, 2018

You are at the beach on vacation, the breeze gently wafts around you; the ocean shimmers. Your mind wanders: about the work that will have piled up during your time off; about your boss who is a fault-finding micromanager; or, that situation with your children, your spouse, your parent, the bills… Instead of feeling relaxed, you are now worried and wound up. Your noisy brain has hijacked you away from experiencing the present.

What causes this “noisy” brain?

It may be the default mode network (DMN). The DMN is a relatively recently hypothesized network of brain regions. It is activated when we aren’t concentrating on anything in particular. It is deactivated when we are focused or concentrating. It was discovered by scientists who noticed that when subjects were asked to rest quietly between goal-oriented tasks, they showed more than expected brain activity (assessed by functional MRI or positron-emission tomography) for a resting state.   

Why would the brain be churning like this when resting?  

Not all neuroscientists agree what this default brain activity during the resting state means. Some neuroscientists hypothesize that the DMN brain regions include the prefrontal cortex (which is involved in processing and interpreting information about one’s experiences), the dorsomedial cortex (involved in forming beliefs about others), and the temporal lobe areas (region of the brain where new and old memories are formed). The scientists believe that these areas are activated when you think about yourself and about others in relation to you; therefore, the DMN directs how you store your memories and categorizes your thoughts about the past, the present, and the future.  In other words, some researchers believed that the DMN is where our sense of self or the ego occurs.

This is the positive, organizing aspect of the DMN. However, there is also a negative aspect of the DMN. The negative is that activation of the DMN pulls the person away from the “here and now.” 

The DMN is activated during mind wandering. For example, instead of experiencing all the aspects of being on the beach during your vacation, your mind is directed to the stuff inside your head. If the “data” you have laid down in your DMN memory regarding the thinking of yourself or others are pessimistic or fear-based, when you are “inside your head”--it will be unpleasant for you. In addition, the DMN can be overactivated: this is called “hyperconnectivity” and is associated with rumination. In other words, your mind will be replaying negative events over and over, or catastrophizing, or stimulating self-doubt and self-blame. Not surprisingly, some studies have found that individuals who experience clinical depression have DMN overactivation. DMN hyperconnectivity has also been associated with anxiety. As an analogy, think of a forest with a well-worn pathway through it. The DMN is sort of like that: a well-worn neurologic pathway that you take when your mind isn’t occupied. Mind-wandering can lead to worry, pessimism, and obsessing over what might go wrong and becomes “the default mode.” 

So, how can you “deactivate” this DMN “worry” route? Here are some suggestions.

  • Altering consciousness: Interestingly, some researchers have found that among experienced meditators, mindfulness lowered DMN activity. In other words, this type of meditation quieted the brain.
    • Mindfulness at the most basic level is essentially taking control over your mind.  One way to counteract the DMN “worry tract” is when the mind wanders, bring it back to the moment. By simply paying attention to the sights, smells, and sounds around you, you experience the “here and now.”
  • Change the route: Instead of the well-worn worry path, direct the wandering to think of obstacles as opportunities and the unknown as exciting new frontiers. In order words, think outside the box. For example, rather than letting a micromanaging boss become a worry instigator, flip that to a motivating force for you to brainstorm the type of work and situation where you could flourish instead of flounder.

    • This type of thinking is called a “task positive network.” Neuroscientists have found that obsessing about the negative, or “depressive rumination,” is associated with higher levels of DMN activation and lower levels of a task-positive network; particularly, in those who suffer from clinical depression. 

  • Creative thinking: Move outside the well-worn DMN into other modes of perception. You may want to explore your environment through only the visual; e.g., doing something non-verbal such as painting but in an abstract way.
    • Have you ever looked at what young children draw and paint? A purple monkey wearing yellow mittens; a dragon-lion with blue wings and a red tail; abstract shapes with eyes and long pointy ears. Thinking outside the box means moving out of the old neurologic routes into other ways of perceiving the world around you.
  • Change the channel: Mind-wander into self-reflection that is intentionally positive. Psychologists would call this “adaptive” rather than “maladaptive” thinking. For example, if your mind wanders into mental narratives of your short-comings, change the channel to a positive memory.  
    • Psychologist Martin Seligman called these “signature strengths.”  Daydream about your successes; daydream about the future where you prevail and thrive.

The DMN can become neurologic “ruts” that are deeply “grooved” by habit. Many of us wander into worry as if we were on autopilot. In other words, we don’t think about what we are thinking about. Lowering the noise in our brains is a challenge, but not an insurmountable one. Quieting the mind offers not just a peaceful state but opens dimensions of perception. 

References

Brewer, J. A., Worhunsky, P. D., Gray, J. R., Tan, Y., Weber, J., & Kober, H. (2011). Meditation experience is associated with differences in default mode network activity and connectivity. Proceedings of the National Academy of Sciences, 108, 20254-20259. doi.org/10.1073/pnas.1112029108

Hamilton, J. P., Furman, D. J., Chang, C., Thomason, M. E., Dennis, E., & Gotlin, I. H. (2011). Default-mode and task-positive network activity in Major Depressive Disorder: Implications for adaptive and maladaptive rumination. Biological Psychiatry, 70, 327-333. doi:10.1016/j.biopsych.2011.02.003

Raichle, M. E., MacLeod, A. M., Synder, A. Z., Powers, W. J., Gusnard, D. A., & Shulman, G. L. (2001). A default mode of brain function. Proceedings of the National Academy of Sciences, 98, 676-682. doi.org/10.1073/pnas.98.2.676

Seligman, M. E. P., Rashid, T., & Parks, A. C. (2006). Positive psychotherapy. American Psychologist, 61, 774-788. doi: 10.1037/0003-066X.61.8.774

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