Sarah SteventonAnxiety Specialist & Psychotherapist
Warwick, Stratford Upon Avon, Leamington Spa, Warwickshire
Warwickshire Specialist Anxiety Centre

The process & neuroscience behind it. brain

The neuroscience behind anxiety and why you aren't able to stop it yourself

To understand the process, it is important to understand a little more about how the brain evolved, and the impact this has on how the brain processes information.

We have grown a reasonably complex brain, that has evolved over 200,000 years or so of human evolution.

The brainstem, which is located at the base of the skull, is the most primitive part of the brain and contains very basic parts for our functioning, which automates heart function and lung function, which is why we don’t have to think to breathe.

The Hypothalamus came next in the evolution process, and not only does the hypothalamus drive very important basic functions for humans, such as sleep, appetite, thirst, motivational drive, and libido, it is also involved in the process of kicking off a cascade of hormones that create the physiological symptoms that someone describes as feeling anxious.

The hypothalamus gets input from other important structures, such as the hippocampus and the amygdalae, which we will come onto shortly, but they are involved in memory production, and this is very important, when we think of memories input to the hypothalamus to tell us what we’ve learned before.

Our evolutionary story is now progressing over many millions of years at this point.

Next came an area known as the as the limbic system. The limbic system is involved in emotions - very pure, raw emotions. So primal things we feel: anger, fear, and so forth. Not the thinking that occurs with it - the thinking of emotions, that’s a later process.

A key part of the limbic system is the amygdalae, which we have two of, so a singular would be an amygdala. The amygdalae are involved in threat detection and in memory, but they’re involved in a particular type of memory. They’re involved in fearful memories. The reason we have this is it’s really important that organisms particularly remember aversive events and this helps avoid negative experiences in the future.

So now we have an organism that’s got a brain stem to help control its organs. On top of that, it’s got a hypothalamus that’s controlling eating, drinking, sexual reproduction. On top of that, we now have a limbic system so that we can feel emotions and a hippocampi/amygdalae system that can remember it.

So our organism is now getting more complex and its brain is getting bigger.
The final part of our story is the bit that grew on top of that - the cortices, and that’s the part that ultimately makes us human.

This newest part of the brain is known as the frontal lobe. The frontal lobe is divided in two: the part of the brain that controls motion - the primary motor cortex - and then everything else which is the Prefrontal Cortex (PFC).
The PFC is involved in the higher parts that make us human- personality expression, social awareness, goal-setting, paying attention, task-switching and executive functioning. It is the logical, rational part of the brain.

So now we have thought about the evolution of the human brain, which was important because we need to know the different structures in the brain, or at least their major overview.

Now we can think about how the brain communicates. How certain parts of the brain send information to other parts of the brain to instruct it to do something.

The brain is a staggering communication device, it’s the most complicated machine in the known universe. Most people have heard of neurons, which are the cells in the brain, but they may not know that one neuron talks to another.

The brain has 100 billion neurons - that’s as many neurons as there are stars in the Milky Way.

A typical neuron will have 30,000 other neurons communicating with it. A model I often give for this is, if you imagine standing in the middle of a football stadium, and you could reach your arms out and touch every single person in that stadium, and they could communicate with you. That’s what a neuron can do, ever single person, all 30,000 could communicate.

Neurons are typically only micrometres long, but they can be very long. A neuron can be up to a metre long. If you move your toes, if you wiggle your feet, that involves two neurons: the neuron that goes from your motor cortex to your spinal cord, that will sign up to the second neuron, and will travel all the way down to your toes.

Neurons are involved in information processing of threats.

Salience is the principle of evaluating stimuli around us, and very rapidly and coming to a decision about it. For example, if you walk into a room, and you see people talking, and someone looks at you and smiles, we need to make a very quick decision on that. Was the person looking at us, what was their intention, and so forth. This is a very important process to help us rapidly come to a decision about our environments and whether it’s threatening or whether it’s friendly.

I hope it is now starting to make sense at this point that this is a very early part of our brain’s evolution. This is an important thing for our limbic system. It was important hundreds of millions of years ago. We needed to rapidly assimilate environments. We often didn’t have time to sit around and think ‘What should I do? Should I stay or should I go? Who is this person? What’s their intent?’ So it’s a very rapid decision-making system that weighs up information in favour against threat.

We can, of course with our prefrontal cortex, assimilate afterwards, but that’s after we make the initial decision – and after we are already sensing a threat.

The neurons form a complex physical network, a matrix if you like, something like millions of hairnets one on top of the other, each layer connecting with every one of the other layers. There are millions of neurones active at any one moment and the connections in the network are constantly changing according to whatever is being or has been experienced. Every impulse that comes in from the outside world – and there are millions of them every second – is tested to see if it is part of a recognised pattern so that some sort of suitable response can be triggered. By the time we are aware of them, those impulses have been tested literally millions of times and so we either know what to do, or we discover that we don’t know what to do and have a need to find out. If we can’t find out quickly, then we suffer stress.

Earlier I mentioned the hypothalamus – and how important it is to the story.

The stress response begins in the brain (see illustration above). When someone confronts an oncoming car or other danger, the eyes or ears (or both) send the information to the amygdala, an area of the brain that contributes to emotional processing. The amygdala interprets the images and sounds. When it perceives danger, it instantly sends a distress signal to the hypothalamus.

When someone experiences a stressful event, the amygdala, an area of the brain that contributes to emotional processing, sends a distress signal to the hypothalamus. This area of the brain functions like a command centre, communicating with the rest of the body through the nervous system so that the person has the energy to fight or flee.

The hypothalamus can be thought of as the command centre. This area of the brain communicates with the rest of the body through the autonomic nervous system, which controls such involuntary body functions as breathing, blood pressure, heartbeat, and the dilation or constriction of key blood vessels and small airways in the lungs called bronchioles.

The autonomic nervous system has two components, the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system functions like a gas pedal in a car. It triggers the fight-or-flight response, providing the body with a burst of energy so that it can respond to perceived dangers. The parasympathetic nervous system acts like a brake. It promotes the "rest and digest" response that calms the body down after the danger has passed.

After the amygdala sends a distress signal, the hypothalamus activates the sympathetic nervous system by sending signals through the autonomic nerves to the adrenal glands. These glands respond by pumping the hormone epinephrine (also known as adrenaline) into the bloodstream. As epinephrine circulates through the body, it brings on a number of physiological changes. The heart beats faster than normal, pushing blood to the muscles, heart, and other vital organs. Pulse rate and blood pressure go up. The person undergoing these changes also starts to breathe more rapidly. Small airways in the lungs open wide. This way, the lungs can take in as much oxygen as possible with each breath. Extra oxygen is sent to the brain, increasing alertness. Sight, hearing, and other senses become sharper. Meanwhile, epinephrine triggers the release of blood sugar (glucose) and fats from temporary storage sites in the body. These nutrients flood into the bloodstream, supplying energy to all parts of the body.

All of these changes happen so quickly that people aren't aware of them. In fact, the wiring is so efficient that the amygdala and hypothalamus start this cascade even before the brain's visual centres have had a chance to fully process what is happening. That's why people are able to jump out of the path of an oncoming car even before they think about what they are doing.

As the initial surge of epinephrine subsides, the hypothalamus activates the second component of the stress response system — known as the HPA axis. This network consists of the hypothalamus, the pituitary gland, and the adrenal glands.

The HPA axis relies on a series of hormonal signals to keep the sympathetic nervous system — the "gas pedal" — pressed down. If the brain continues to perceive something as dangerous, the hypothalamus releases corticotropin-releasing hormone (CRH), which travels to the pituitary gland, triggering the release of adrenocorticotropic hormone (ACTH). This hormone travels to the adrenal glands, prompting them to release cortisol. The body thus stays revved up and on high alert. When the threat passes, cortisol levels fall. The parasympathetic nervous system — the "brake" — then dampens the stress response.

So how do we stop the primitive part of the brain perceiving a situation as threatening and kicking all this off.

How do we change the response to a given situation, that cause the feeling of a threat - like standing up in front of a group of people, or driving on a motorway, or travelling on a tube, or picking up a small spider and putting it out of the window.

Well essentially, we circumvent the circuit. So we stop the process in its tracks.

Information has to travel from one area of the brain to another, by way of neurons. Some of these neurons are travelling at a snails pace, and some at around 200 mph.

So the part of the brain that detects a 'threat' has you responding, before you are even consciously aware, because the primitive brain starts making decisions about how you should respond ie; whether you should run, or fight - so by the time the rational logical part of your brain (your prefrontal cortex) gets the message, you are already feeling anxious.

However, there is a very small amount of time, a split second, where your brain is in the 'wait phase' or the 'testing' phase - where the data (ie; the situation in front of you, or what you are imagining, or what you are sensing in your body) is being matched to previous situations that you have experienced, or anything similar that might indicate if this is a threat or not, ie; what you have learnt is scary, and your natural instincts, which were embedded when you were in the womb.

This waiting/testing phase is literally milliseconds, but that give us a window of opportunity to break the circuit.

The process & neuroscience behind it. Larger mesencephalon image

How we actually make the change is pretty simple.

So we know the brain is constantly checking our surroundings for threats.

During this processing of checking, if something doesn't feel right the brain has a brief 'wait state', where it requires more information to decide if the situation is safe or not safe - this is often referred to as the 'freeze' response.

It is this 'Freeze' response, that we induce therapeutically and without trauma. We then use the primary communication processes of the early brain to reorganise and neutralise the response(s) associated with the presenting symptom.

So we are essentially artificially replicating the 'wait phase', then immediately imbedding a more appropriate response (chosen by yourself) at the vital moment, so that the brain accepts the 'preferred response' as valid and this becomes the new response in the future.

The process is fairly simple to execute - it does however require an amount of analytical preparation.

This analysis and preparation is done by Sarah during the intake session, where she will go through a thorough and detailed history with you. This then enables her to work out exactly what is happening in your particular situation and why, and from this she will create the precise structure necessary in terms of your specific sessions required to resolve your symptoms.

The whole process is based on neuroplasticity, which is the brains ability to create new pathways. This is a natural process that is continually happening within your brain. Every time you learn something new, your brain builds a new pathway - and it is this natural process that we are utilising.

See the process in action here Neuroplasticity

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