What Happens to Your Body When Your Brain Is Thinking?

 Alison Czinkota / Verywell

What happens to your body when you're thinking? You might think that is a simple question to answer: a thought is just words in your brain that cause you to do something, right? In reality, this question has plagued scientists for decades and the precise answer is still something that is the subject of research.

For this reason, it's not something that can be clearly described in a flowchart format. However, what we can do is break down what we do know about our thoughts and then try to put the pieces of the puzzle together to create a picture of what is happening.

What Is a Thought?

The first problem with describing what happens in your body when you are thinking is that not everyone agrees on what constitutes a thought. At first glance, you probably think of a thought as something that you tell yourself.

For example, this morning while lying in bed you might have had the thought, "I don't want to get up."

Let's take a moment and deconstruct that thought to try and figure out exactly what it is.

Is the thought "I don't want to get out of bed" something that spontaneously appeared in your mind? Or was it triggered by something? Is it just a physical process of your brain or the manifestation of something deeper like a soul, spirit, or other entity?

Phew, that's a lot to think about. And, depending on who you ask, you will get different answers.

Reductionism vs. Dualism

While scientists might apply reductionist theory and predict that thoughts are simply physical entities that can be explained by chemical changes in the brain, philosophers or other theorists might argue a more dualistic theory that your mind is separate from your body and your thoughts are not physical parts of your brain.

All that aside, if we want to consider what happens in our bodies (or specifically our brains) when we are thinking, then we need to at least acknowledge that our thoughts can influence our bodies.

We know this to be true for a number of reasons. For example:

  • Stress (or negative thoughts) can worsen physical illness
  • Fear can lead to increases in certain chemicals that prepare us through the "fight or flight" response
  • Thoughts start chain reactions that allow us to contract our muscles

Since we know that thoughts can influence our brains and our bodies, let's take a look at exactly how they do that and what is happening under the hood (in your head).

Anatomy of a Thought

Let's jump back to that morning thought: "I don't want to get out of bed."

Scientists would argue first that the thought you had was not spontaneous and random. Instead, your thought was likely a reaction to something around you.

In this case, it might have been an alarm clock, checking your phone to see what time it is, or hearing something like the garbage truck go by that reminds you of time passing. In other cases, thoughts might be triggered by memories.

Now, once you have that thought, what happens?

Some Neuroscience Terms Defined

In order to understand how thinking happens in the brain, there are some key terms you know more about:

  • Action potential: Sudden burst of voltage caused by chemical changes (how neurons signal one another)
  • Neuron: A nerve cell through which signals are sent
  • Neurotransmitter: Chemical messengers released by neurons that help them communicate with other cells (e.g., dopamine, epinephrine, norepinephrine)
  • Prefrontal cortex: Part of the brain involved in planning, personality, decision making, and social behavior.
  • Hippocampus: Part of the brain crucial in a variety of memory functions.
  • Synapse: A structure that allows a neuron (nerve cell) to pass a chemical or electrical signal to a target cell.

How the Brain Thinks

The brain operates in a complex way with many parts intersecting and interacting with each other simultaneously. So, when you have that thought in the morning, it's likely that all these different components of your brain (prefrontal cortex, hippocampus, neurons, neurotransmitters, etc.) are all involved at the same time.

If the result of your thought that you don't want to get out of bed is that you throw the covers back over your head, what happened to allow that action? Or, if instead you decided that you needed to get up and got out of bed, what happened differently?

We know that when the brain is making a decision, different neural networks compete with each other. Eventually, one of the networks becomes activated and produces the desired behavior.

This happens through nerve cells in the spinal cord called motor neurons that fire and sends an impulse down their axon, which travels to the muscle and causes the action: in this case you throwing the covers over your head or actually getting out of bed.

Thoughts and Emotions

What about the emotional effects of your thought?

We know that your thoughts can influence the neurotransmitters in your brain. Optimism is linked to better immunity to illness while depressive thinking may be linked to reduced immunity.

So, if you throw the covers over your head, and that triggers other thoughts such as "I'm tired," "I can't get up," or "Life is hard," complex interactions in your brain may send signals to other parts of your body.

On the other hand, if you get out of bed and think, "This isn't so bad," "I'm getting going now," or "Today is going to be a great day," the pathways and signals that your neurons send will obviously be different.

We don't yet know all the intricacies of these processes; however, suffice it to say that your thoughts matter.

Your brain is constantly receiving signals, whether from the outside environment in terms of perceptions or memories from your past. It then activates different patterns through waves in the brain through billions of synapses.

In this way, your thoughts grow more complex as they interact with other content produced by your brain functions.

Regulating Your Thoughts

It goes without saying that your thoughts are linked to your emotions in a bidirectional way. How many times have you experienced a shot of adrenaline after having a fearful thought? Have you ever gone to a job interview or on a first date and felt the same?

Whenever you have a thought, there is a corresponding chemical reaction in your mind and body as a result.

Changing Your Thoughts Changes How You Feel

This is important to realize because it means that what you think can affect how you feel. And by the same token, if you are feeling poorly, you can change that by changing how you think.

If that sounds a little unusual, go back to the premise that thoughts are physical entities in your brain (and not spontaneous outside forces that don't connect with your body).

If you accept the scientific view that your thoughts are physical parts of your brain and that changing your thoughts can have an effect on your body, then you've just developed a powerful weapon.

Changing Thoughts Starts With Identifying Triggers

But wait a minute: if our thoughts are always just reactions to something, how can we take control and change them?

Of course, your thoughts don't arise out of a vacuum. For example, you are reading this article and gaining new ideas from it that you can potentially put to use in changing your thoughts.

  • You're starting to think a different way.
  • You've started to feed your brain different information.
  • You've surrounded yourself with information that programs your brain to start thinking the way that you want it to.

What this means is that if you want to start changing your thoughts, you need to be aware of the triggers of your thoughts and also the patterns of thoughts that you have in response to those triggers.

The next time you are lying in bed thinking, "I don't want to get up," ask yourself what triggered that thought.

How to Change Your Thoughts and Change Your Body

Get very clear about the triggers of your thoughts and you will have the power to change your emotions and your health. In the case of the person not wanting to get out of bed, it could be that the alarm clock triggered the thought.

You've got a mental association between the alarm clock and the thought "I don't want to get out of bed."

You've worn a mental groove in your brain, so to speak, that instantly connects that trigger with that thought. So if you want to change that reaction, you either need to change the trigger or break the association with that thought.

Challenge Yourself to Think Differently

One way to do this would be to force yourself to think a different thought each morning for 30 days until that becomes the new reaction to the trigger. For example, you could force yourself to think, "I love getting up" every day for 30 days.

If that thought is just a little too unrealistic, maybe try something like, "It's not so bad getting up. Once I get going I'm glad I got up early."

Changing environmental triggers can also be helpful. For example, you could also change the sound of your alarm so that you're less likely to have that old reaction (the old thought) to the old alarm.

Once you get the hang of this, you can apply it in all areas of your life! For example:

  • Stuck in a traffic jam and feeling irritated and frustrated? The thought, "I can't stand traffic" will send signals from your brain to your body to speed up your breathing and tense your muscles. Whereas the thought, "I can't control this, might as well relax," will send the signal to your body to calm down.
  • Worried about an upcoming presentation? The worried thought, "This will be awful, I am so anxious" will leave you feeling panicked and on edge, whereas the thought, "I'm doing my best, that's all I can do" will help to send signals to your body that it's okay to be calm and relaxed.

Impact of Brain Damage and Disease

We know that lesions to specific parts of the brain damage specific cognitive abilities. This is interesting because it highlights the point that thoughts really are physical entities that both influence and are influenced by the body.

Cognitive functions depend on all parts of the brain working properly; when these systems become disrupted, thinking can be affected.

In addition to traumatic brain injuries, diseases can also have an effect on thinking. Examples include Alzheimer's disease, Parkinson's disease, ALS, and stroke. Brain damage caused by these conditions can affect:

In addition to affecting aspects of thinking and behavior, brain injuries can also have lasting physical effects including headaches, dizziness, hearing loss, vision loss, sleep problems, and fatigue. All of these issues can then affect how a person thinks.

A Word From Verywell

While it's true that there is a lot we still don't understand about the mind, body, universe, etc., it's fairly obvious that at the very least, thoughts can have a direct influence on reactions in the brain and body.

This is the basis of many forms of talk therapy, such as cognitive-behavioral therapy. This can allow you to change your thinking, you are also doing something that can have a positive impact on your brain and your body. As you build new neural pathways and develop healthier thinking habits, these changes can be long-lasting.

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Arlin Cuncic, MA
Arlin Cuncic, MA, is the author of "Therapy in Focus: What to Expect from CBT for Social Anxiety Disorder" and "7 Weeks to Reduce Anxiety." She has a Master's degree in psychology.