CU Boulder graduate student researcher Jacob DeRosa delves into the brain’s ability to remove unwanted thoughts

Imagine trying to fall asleep, but your brain won’t cooperate. You tell yourself to let go of the embarrassing conversation from earlier in the day that keeps looping through your head, for example, but you can’t stop thinking about it.

Why are some thoughts so hard to dismiss?

It’s a question University of Colorado Boulder psychology and neuroscience graduate student Jacob DeRosa has been pondering for years. Now, with a newly published study in NeuroImage. Clinical, DeRosa and his co-researchers may be closer than ever to understanding what makes some brains better at letting go of unwanted thoughts—and why other brains tend to get stuck.

Jacob DeRosa, a CU Boulder psychology and neuroscience graduate student, studies the question of why some thoughts are so hard to dismiss.

“Why is John really good at getting a thought out of his mind and going on with his day and I’m not?” DeRosa says. “This thought just seems to get stuck up in my head, and I’m thinking about it over and over and over again.”

That puzzle—why some people can suppress a thought and move on while others can’t—drove DeRosa to design a study that explores the neuroscience behind thought control.

The findings point to specific brain patterns and networks that may explain why some of us struggle to quiet our internal noise.

A question of control

Before tackling the nuances of thought control, DeRosa wanted to define what it actually means to “control” a thought. He and his team focused on four mental operations that are performed in working memory—the brain’s active thinking space.

The distinct tasks they studied included maintaining a thought, replacing it with a new one, suppressing it entirely or clearing the mind completely.

“What am I doing when someone tells me a phone number? Am I switching it with other information? Am I suppressing it? Or am I clearing my mind completely?” DeRosa asks.

To get to the bottom of it, study participants were asked to view and manipulate words in their working memory while undergoing functional MRI scans. This allowed researchers to observe when different parts of the brain activate and determine whether those patterns vary between people with and without self-reported difficulties in controlling unwanted thoughts.

They found that participants who reported more trouble controlling their thoughts showed less distinct neural activity across the four control operations.

“We’re basically creating a map of the brain,” says DeRosa, “and we’re looking at, well, how organized are these networks when someone is removing information?”

Hoping to better understand which regions play a role in thought removal, the team started looking closer at how they were recruited during different operations.

“What we found is that people who are really good at controlling their thoughts have really distinct color patterns for each operation. People who aren’t have a similar color pattern across the four operations, which tells us there’s not a lot of distinct activity happening,” DeRosa explains.

That lack of distinctness, when the brain isn’t clearly switching between tasks like suppression and replacement, could be why some people struggle to get rid of unwanted thoughts.

 

“It’s going to take some time to get more organization in your brain and get it working together to remove those thoughts, but it’s definitely possible,” says CU Boulder researcher Jacob DeRosa. (Photo: Pexels)

“There seems to be more of this blending across the brain in terms of what’s happening when someone is trying to remove a thought. What it tells us is that these individuals aren’t able to precisely implement a certain operation,” he adds.

In other words, your brain might try to use the same mental tool for every task—like using a hammer for every job, when what you really need is a screwdriver.

But perhaps more importantly, DeRosa’s study found that this neural blending didn’t show up when people were at rest. It only emerged when they were actively engaged in trying to remove or control a thought.

DeRosa says the nuance matters.

“It’s not that people’s brains are just disorganized in general. It’s actually when it comes time to remove the information where we see them having a harder time,” he notes.

Bridging brain scans and mental health

Although anyone can have difficulty controlling thoughts, it’s also a common symptom of a range of mental health conditions, including depression, anxiety, post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD). DeRosa believes that mapping out the brain mechanisms responsible for thought control can help researchers identify objective markers for these disorders and even ways to track how treatments are working.

“What’s nice about this initial study is that it gives us a baseline. Now we can begin to compare between high- and low-internalizing populations and eventually move on to even more specific psychiatric populations like depression, anxiety and PTSD,” he says.

The good news for everyone is that thought control isn’t necessarily a fixed trait.

“Our biggest takeaway is that it’s possible for anyone to practice getting better at thought control. I think beginning to practice these operations when unwanted thoughts come in is helpful for people because they can begin to differentiate what’s working for them,” says DeRosa.

That idea reframes thought control not as a matter of brute force willpower or something in our genetics. Rather, it’s a skill that can be trained and supported, whether through mindfulness, cognitive behavioral techniques, journaling or simply paying attention to what works for you.

For anyone who’s ever felt stuck in a spiral of unwanted thoughts, DeRosa’s research offers a glimpse of both clarity and hope. Of course, he also cautions that improvement doesn’t happen overnight.

“It’s going to take some time to get more organization in your brain and get it working together to remove those thoughts, but it’s definitely possible.” 

Researchers Harry Smolker, Hyojeong Kim, Boman Groff, Jarrod Lewis-Peacock and Marie Banich also contributed to this study.

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