In the last post we talked about a model of the brain as having three parts, each part with its own goals and methods of existing in the world. Each part of the brain manifests anxiety in a different way. But the brain is much more than parts. There are also pathways of communication between different areas of the brain. Communication happens when nerve cells, also called neurons, “fire” and send signals from one area of the brain to the other. The pathways these nerve cells travel are important to our experience of anxiety and relief from it.
As we mentioned previously, there are two different circuits in the brain that control anxiety. One we call the Worry Loop, the other we refer to as the Fear Circuit. Whereas the Fear Circuit taps into the mammalian and reptilian brain parts we discussed in the last post, the Worry Loop primarily acts in the part of the brain that is most developed in humans.
Worry, Plan, and Act
We’ve talked before about anxiety being something that has a positive purpose. We have anxiety to keep us safe, and the same is true for worry. As uncomfortable an emotion as worry is, it serves a function. Worry helps us plan for the future, so that we can take action. We need some measure of worry. This is why we have a Worry Loop, to carry out the sequence: Worry, Plan, and Act.
The Worry Loop is important in cognitive control, determining what is important to pay attention to and telling the rest of the brain what to do about it. The brain is hard-wired to zero in on a problem, turn it over a bit, come up with a plan, and act on that plan. Being able to carry out the sequence Worry, Plan, and Act is part of what makes us human.
Unfortunately, sometimes we worry, plan, say, “What if?” worry some more, plan some more, second-guess our plan, worry about our plan, worry about our second-guessing, then worry about how much we’re worrying. At this point, we’re stuck on repeat in the Worry Loop. Sometimes we never even get to action. Or we act, but still don’t stop worrying. Half the time, the part we are worrying about is completely out of our control to begin with.
Signs of the Worry Loop
The name pretty well sums up what this circuit does. It thinks about a problem – on loop. If you have a tendency to worry, you know the feeling well, and you are probably accustomed to three of worry’s components: anxious misery, dread, and obsessions.
Anxious misery is that feeling that clearly separates worrying from delightful daydreaming. You have anxious misery when you worry about whether that cough is COVID, not when you daydream that you’re about to get a paid day off. It’s the gnawing feeling that separates the two thoughts. While hard to put into scientific terms, you know it when you feel it.
The second component is dread. You know dread. It’s that feeling that something awful is about to happen. Some people may have the experience of a specific thing (or many specific things) that is about to happen. Maybe every time the phone rings you dread somebody has just been in a car wreck. Or maybe it’s the vague feeling of expecting the worst in every situation.
Obsessions are what separate fleeting experiences of anxious misery or dread from worry. Obsessions mean that you are thinking about the same unpleasant thing over and over again. On a loop.
You may be able to break out of it eventually, but if you’ve gone through the same cycle of thoughts a few times, those are what we’re calling obsessions. We’ve all been there. You don’t have to qualify for a diagnosis of Obsessive-Compulsive Disorder to experience obsessions occasionally.
The opposite of obsessions is being able to let the worrying thoughts come into your mind once, observe them with a detached, “How interesting,” and let them drift out of your head again. Few of us can do that all the time, but some of us worry more than others.
The Worry Loop as a Nerve Pathway
The Worry Loop is a loop in more ways than one. Not only does it remind us of looping backward in the Worry, Plan, and Act sequence, but it foremost means the looping brain circuits that make the Worry, Plan, and Act sequence possible. It’s intriguing to me that what feels like thoughts on loop in our minds is also chemical signals on loop through circuits in our brains.
The tract we call the Worry Loop is a bundle of nerve cells that runs between three parts of the brain, the prefrontal cortex (the rational, thinking part of the brain), the striatum, and the thalamus, then back to the prefrontal cortex. Because of that pathway, the formal name for these nerve cell tracts are CSTC loops. We have a number of these loops, but like most structures of the brain, it’s easier to call it just one Worry Loop.
The part of the prefrontal cortex that involves the Worry Loop is a thin layer on the surface of the brain that sits directly behind your forehead called the dorsolateral prefrontal cortex. That’s a long term meaning “top-side part of the very front of the cortex.” This part of the brain is key in planning and cognition, with cognition basically being a fancy word for thinking.
It makes perfect sense that our worries loop over and over through the part of the brain that plans and thinks, because this is basically how we perceive worry. The Worry Loop is also commonly called cortex-based anxiety (since the cortex is involved), and both names describe important aspects of this brain circuitry.
After the nerve impulse leaves the prefrontal cortex, it travels to the striatum. The Worry Loop connects to the top part of the striatum, which seems to directly contribute to decision-making, particularly to choosing and starting actions. Think of this part of the brain as key to committing to a plan and carrying out the action in the Worry, Plan, and Act sequence.
From the striatum, the Worry Loop continues on to the thalamus. The thalamus sits in the very center of the head. It’s the control center of the brain. It’s like the old telephone call operators. You would pick up the phone and ask the operator to connect you to your mother’s house. She would then physically plug in a wire to connect your phone to your mother’s phone. The thalamus works a little bit like this. It takes in all the sensory information, thoughts, emotions, memories, everything that goes on in our brains, assesses where they need to go, and connects those signals to the other relevant parts of the brain.
You could also think of it as Grand Central Station. All trains of thought connect back to the thalamus eventually. The thalamus sends its conclusions to wherever they need to go and brings the prefrontal cortex images and input to worry about.
Neurons that Fire Together Wire Together
There is a saying in neuroscience, “Neurons that fire together, wire together.” When we use neurons at the same time over and over, they start firing together more and more often. Without getting too technical, take this example. If you think about your boss’s critical tone while you take the elevator to go to lunch, you are more likely to think about your boss again tomorrow on the elevator. Once you’ve done it a few times, you’re likely to think about your boss every time you get on the elevator. You’ve built an association between your boss’s tone and the elevator. The neurons that recognize you’re on the elevator have wired with the memories and emotions of getting criticized by your boss.
Likewise, worry reinforces worry. We build associations when we worry, and the more we worry about something, the more we buy into the idea that it’s something worth worrying about. So we run through the Worry Loop more and more.
Fortunately, the brain is amazingly adaptable. Just because we have associations that keep us worrying instead of committing to a plan and acting on it (or deciding how to keep ourselves occupied if we can’t do anything about it) doesn’t mean we are stuck in those patterns forever. We can break them. But just like any bad habit, it takes intention, practice, messing up, and trying again to get out of the Worry Loop.