Why do I find this topic particularly important today?
Considering the countless anxiety disorders, I continually find an almost incalculable amount of interesting facts on this topic. And this despite the fact that I write about it from time to time, e.g. here, I would like to share some of these facts with you in this blog and those of the coming months. After all, 36% of all people in western countries between 18 and 60 suffer or have suffered from an anxiety disorder. The ongoing Corona situation is making us slowly realise its psychological consequences. For example, 41% of the 18-29 year-olds in the US have now developed clinically relevant anxiety disorders.
It is maybe best to start by explaining how fear gets into our brains – and into our bodies.
Which of our five senses are particularly important for the development of fear in the brain?
Smelling is an exception
Our sense of smell is the most direct of our sensory systems. Only smells go immediately into the olfactory brain without a filter and from there into the limbic system without the involvement of more rational evaluation systems. In this – oldest – part of our brain, decisions are made about possible strategies. Do we play dead, flee or attack? Or should we have sex? And although we only have about 30 million olfactory cells (dogs have 300 million), we can distinguish up to a trillion scents with them. So you can smell other people’s fear – which in turn triggers fear in you.
Since smells go from the olfactory brain not only to the limbic system but also to the hippocampus, which manages our memories, and other things, you can remember smells associated with important life events – both positive and negative – for the rest of your life.
And although we cannot rationally explain or explain away smells, they have a strong influence not only on our feeling of well-being, but also on our brain activity.
You can already see here how much smells and anxiety are connected. Evolutionarily, the fear of the smell of smoke or unexpected smell of blood is very helpful, as is the smell of sweat from an aggressive man. On the other hand, it is not very helpful if the memory of a bad experience in an environment that actually smells good triggers fear or sadness in the further course of your life.
Smell as the most important access to new experiences.
This is particularly problematic for you if smells are an important channel for perceiving and learning.
For example, I had a client who used to judge the papers of a certain colleague negatively. When I explained to her that people use their sensory organs differently for learning and understanding – some learn when they see something, others when they hear something and some just when they smell something – she remembered that these papers always had a smoke smell that was disgusting to her. So she was not repelled by the contents of his papers, but only by their smell.
Can you train the olfactory system?
In a test, for example, old people felt younger and could demonstrably express themselves better after being ” scent-trained” for three months. The control group had to solve Sudokus – unfortunately without positive effects (source).
Fortunately, you can also train and change your olfactory system. There are even two ways to do this. You can try to identify the smell that is associated with an event that triggers fear. Then you combine it again and again with positive experiences. If, for example, the smell of freshly baked cake always makes you sad because you once got the news of a loved one’s death while baking, you could invite friends to bake a cake together and thus overwrite the old memory.
You can also carry another very nice scent in a bottle. If you notice that a smell makes you sad or angry or nervous, you can cover up the current smell by taking a whiff of this bottle.
It is also helpful to consciously train your olfactory brain. For example, you can learn to distinguish between certain types of wine just by smelling them. This probably also works with honey or mustard or beer. Depending on your preferences, flowers, grasses or other smells are also suitable for training your sense of smell and thus teaching it a variety of new – usually positive – smells.
Why is olfactory system training important?
Scientists are seeing increasing evidence that the losses in smelling and tasting in many mental illnesses, including anxiety disorders and depression, are the consequence of the illness rather than the cause. So if sadness and negative thoughts dominate your life, you may suffer losses in smelling and tasting. This would be a serious disadvantage in real dangerous situations. Above all, however, you would no longer be able to enjoy so many beautiful moments in life.
How do hearing, seeing and touching influence our feeling of fear via certain brain regions?
While stimuli from hearing and seeing, in contrast to smelling, first move into the thalamus, where they are evaluated before a corresponding reaction occurs, with tactile stimuli it is sometimes like this, sometimes like that. Normal tactile stimuli such as airflow on your skin or the light touch of your hand first run, like auditory and visual stimuli, to the thalamus and then to the sensorimotor complex in the cerebral cortex. There, these stimuli are evaluated and corresponding reactions are triggered. Dangerous tactile stimuli, by contrast, are already linked in the spinal cord with neurons that trigger reflexes such as flinching without involving the cerebral cortex. (For example, when you touch the hot cooker top).
Which brain regions are significantly involved and where exactly do they lie?
The process flow in the brain is managed by four important brain areas: the thalamus, the amygdala, the hippocampus and the cerebral cortex.
In order to get a picture of these parts of the brain, imagine that you can see into the other person’s brain through their eyes.
At the height of the eyes in the brain’s centre, slightly above the point where the brain stem terminates the spinal cord, there are two almond-shaped nerve cell clusters on either side. This is the amygdala (or almond nucleus). Attached to it is the hippocampus. Hippocampus is also the Latin name for a seahorse – the shape of this brain region looks like a seahorse. And between the amygdala nuclei lies the thalamus, below it the hypothalamus and behind it the epithalamus. These structures are also distributed in both halves of the brain. The cortex structures then build up around this very old core of our brain. Because of the arrangement of these core structures like a rim around the brain stem/spinal cord, it is called the limbic system (limbus = rim).
(If you need a picture to help you visualise this, look here).
Amygdala, hippocampus and thalamus are already found in fish and reptiles. That is why this brain part is still referred to as the reptile brain. It is therefore very old in terms of evolutionary history. In this brain region behaviours that are important for survival are evaluated, triggered and stored as memories. It controls primal emotions – fear, anger, joy as well as our sexual behaviour. The amygdala also controls numerous vegetative functions such as breathing, our sleep-wake rhythm and our motivation.
The thalamus
Before the frightening moments reach the amygdala at all, they must first pass through the thalamus. The thalamus is the mediation centre for messages from all sensory organs except – as described above – the sense of smell and tactile impressions, which immediately lead to reflexes. All others are roughly filtered here and then passed on to the amygdala. This is also the switching point for these sensory impressions – coming from outside into the individual brain areas where their concrete processing takes place.
Even though it is not yet known whether the structures of the thalamus can be damaged by fears or anxiety disorders, it is certainly helpful to train this area of the brain. The best way to do this is to train your senses (see above for the sense of smell).
There are special trainings for both seeing and hearing. Opticians even have additional training as functional optometrists. These are people who can help you improve your ability to see – especially important if you already have an eye problem. But you can also do a lot on your own to improve your eyesight and focus. You can find exercises here, for example. The same is true for hearing. Here, too, there are interesting exercises on the net, for example here. Especially the latter link makes it clear that our brain is exercised and trained above all by new stimuli and by mindful perception of stimuli that are otherwise filtered out by the thalamus because they are not important.
The amygdala
The amygdala is the crucial structure for evaluating and storing fear-inducing situations emotionally and for triggering the necessary reactions. In acutely threatening situations, the central nucleus of the amygdala has the ability to trigger physical reactions without further consultation of other brain parts, allowing for correspondingly rapid action.
These nuclei also have the ability of storing memories of threatening situations. This enables us to react even faster – an extremely sensible mechanism from an evolutionary point of view. Studies suggest that the two amygdala nuclei are responsible for different emotions. In particular, the right part is associated with negative emotions and immediate intervention when threatening events occur. The left one possibly stores more positive information.
You can see how extremely complex our brain is by the fact that the amygdala is not a consistent structure in itself, but consists of different regions whose functions are gradually being deciphered. The BNST region, for example, emits certain neurotransmitters, the activation of which, according to current studies (source), leads to the physical symptoms – palpitations, sweating, dilation of the pupils.
Does the amygdala change in people with anxiety disorders (and also depression)?
Not surprisingly, the amygdala is noticeably enlarged in people with anxiety, because it is in action practically all the time. This is not just the case with significant anxiety disorders, but already with children who are particularly anxious. Once again you can see that we cannot be sure what is cause and what is consequence.
If you suffer from anxiety, you should know that the enlargement of the amygdala not only causes greater feelings of anxiety. As a result of the enlargement, it is also responsible for the fact that you may prefer to avoid decisions that could be associated with risks. Unfortunately, this is also true for decisions that involve risk but also have a high positive potential. You may then decide to opt for the known safe situation. And not for the better-paid job closer to home.
How can the amygdala be reduced?
However, it is definitely possible to reduce the size of the amygdala. Sometimes it is enough to exercise regularly. In addition, you can use meditation and yoga to noticeably reduce the size of the right amygdala-nucleus.
In acute fear situations, it is also helpful to turn on the light! The amygdala reduces its activity in light because it is directly connected to the retina. In the light, thoughts that seem very threatening or frightening in the dark are therefore clearly less frightening. This is because the reduction of amygdala activity gives more weight to the prefrontal cortex with all its rational considerations of the situation.
Especially the combination of meditation and light helps to calm down and, if necessary, to reduce the amygdala.To do this, you can simply take a normal calming meditation and then enrich it when you have reached a deep state of relaxation. At this moment, remember where this inner core of your brain is located with the two almond-shaped nuclei. Now imagine breathing in light (white, silver, gold, pink… depending on your preference). Let this light flow through your nose into your brain. Let the amygdala bathe in this light as your relaxation deepens. When you feel that your amygdala is sufficiently supplied with light for the moment, come back from the meditation. (In perspective, there will also be a recorded detailed exercise on my site).
If you do this exercise regularly (minimum 10 minutes over 66 days), you will reduce the probability of anxiety. In addition, you can call up this light more easily in an acute anxiety situation and thus calm yourself down faster.
The hippocampus
From the amygdala, the information goes to the hippocampus, where the memories of the relevant events are formed as patterns. As you can see, the process of fear is quite complex. Even neuroscientists still have a long way to go in understanding everything about how our brain works.
Because the hippocampus is the place where memory patterns are formed, it is also responsible for our ability of learning and remembering new things. It is also an interface, this time between short-term and long-term memory. In other words, between what is formed in the amygdala as a memory and then stored in different areas of the brain as a long-term memory.
Does the hippocampus also change in people with anxiety disorders (and depression)?
Yes, the hippocampus is often reduced in anxious and depressed people – but here this seems to be clearly the consequence of the current life situation and not the cause. The constant stress of an anxiety disorder leads to increased cortisol levels in the body. The nerve cells of the hippocampus apparently have a hard time coping with this. There are many docking sites for cortisol here, which simply stop working when they are used more than average, causing these cells to break down.
How can you train the hippocampus and thus enlarge it again?
Since the hippocampus is also very important in old age as the most important transmission point for newly learned information, there are studies on how you can train the hippocampus, especially in relation to dementia. Again, the best thing you can do is to exercise moderately. With age, the hippocampus shrinks on average by 1-2% per year. Subjects who did cardio exercise three times a week for a year not only kept their hippocampus from shrinking, but actually increased it by 2% compared to the group that did stretching exercises three times a week. Parallel to the growth, the subjects were also able to increase their memory performance.
Another study with patients suffering from schizophrenia supports these findings. The test persons involved either rode bicycles or played table football. Here, too, the physical activity – cycling – led to a significant increase in the size of the hippocampus, this time by as much as 16% ( source).
You can achieve even better results by combining physical and mental training.
And break out of your daily routines. Take a different route home, alter a particular recipe or devise a complicated knitting or crochet pattern. Learn a new language or do some other kind of continuing education. Learn to programme, study the plants around you…. As we have seen above, crossword puzzles and Sudokus are not the way to go here. This is because the solution to these puzzles is based on patterns that, once recognised, our brain simply uses again and again. Nothing new, then.
The cortex
But not only the regions in the “limbus” around the brainstem are associated with feelings of anxiety. Very important seems to be an area in the anterior cingulate cortex – a structure that stretches like a bonnet around the regions described above and which is also counted as part of the limbic system.
What happens in this area?
Excessive activity in this area leads to an increase in negative feelings and a reduction in pleasure. It is also partly responsible for the physical consequences of anxiety and depression leading to heart disease because it controls cortisol levels, for example. This overactivity then acts back on the amygdala, activating it, but at the same time reducing activity in the prefrontal cortex and thus the ability to better regulate the emotions that arise.
The prefrontal cortex also makes the appraisal of fear. However, the information goes from the amygdala to the prefrontal cortex very quickly, but the return path is much slower. This is one reason why it is so difficult for us to reverse the physical symptoms and our negative feelings even when the fear reaction is objectively considered meaningless.
And the most exciting – and admittedly least pleasant – fact is that in people with anxiety disorders, the connections between numerous brain regions increase and deepen – with the effect that the feelings of anxiety become more widespread and consolidated.
Have I given you enough reasons to train the parts of the brain involved in the process of anxiety?
In the hope that I have made this difficult and complex subject understandable and comprehensible to you, I remain as always
Yours, Claudia