From Chapter 3: Laying the foundations for optimal vagus nerve training

The importance of preparing the vagus nerve and interoceptive awareness training

As you know from the first chapter, our interoceptive awareness is an incredibly complex and multi-faceted neural phenomenon. For this reason, it is particularly important for us to focus on the parameters within which the perception and regulation of information takes place. These parameters can be seen as all the elements of your brain and nervous system that, irrespective of what’s actually happening inside the body, interact closely with the insular cortex and affect its functionality. These elements hold the key to increasing your interoceptive awareness, raising your fitness levels and improving your overall health.

This chapter is about building the proverbial ‘framework’ for your further training, to maximise the impact of your training and make sustainable improvements to your interoceptive accuracy. In Chapters 4 to 7, we will be showing you how to train individual components that each have a major impact on your health in and of themselves, helping to reduce stress, improve fitness and give you a greater sense of wellbeing. It is of course possible to train each element individually, but it is only by creating a strong foundation – i.e., by establishing the optimum parameters – that you can really make headway with your training.

We have designed this book to offer you a comprehensive and holistic perspective on this issue, focusing on the neural principles and relationships that govern your health and wellbeing. Our main focus will be on stimulating the frontal lobe, an area of the cortex that communicates intensively with the insular cortex, as well as improving the functionality of the vestibular system, which forms the basis of the entire nervous system. The vestibular system in particular is so crucial to the functions of the insular cortex and interoceptive awareness that we strongly recommend making this a focal point for your training. We will also be stimulating the central section of the insular cortex – which is also crucial to the integration of sensory data – with a series of exercises involving smell and taste. We will then focus on straightening and elongating the cervical spine and mobilising the vagus nerve, in order to improve the mechanical components involved in the transmission of information between body and brain. At the end of the chapter, you will find additional options for stimulating the supplementary motor areas (page 110). These make up an important section of the frontal lobe, which is heavily involved in the coordination and regulation of internal processes.

As you work through this chapter, you will see that the better the parameters are, the more effectively you will be able to train the individual components of your interoceptive awareness. And the overall result? Better health, a greater sense of wellbeing, and improved fitness.

Upregulating the frontal lobe

If you look at how the insular cortex communicates with other parts of the brain, you will see that a significant quantity of information is exchanged between the frontal lobe and the insular cortex. One of the most important roles of the frontal lobe is to control or suppress unwanted impulses. The brain has to respond to incoming stimuli and give permission to the body to perform or prevent an action: a ‘go signal’ from the brain performs an action, while a ‘no-go signal’ stops it. Go and no-go signals are processed in specific areas of the frontal lobe. If the no-go signal is missing or arrives too late, the unsuppressed impulses trigger inappropriate and disproportionate reactions. This results in your brain using old solution strategies and behaviour patterns, which are often unable to adequately solve the situation. Whether you have difficulties turning down that delicious piece of cake, even when you’re no longer hungry, or breaking a spiral of unhealthy thoughts – any form of behaviour change relies on the ‘no-go signal’ and needs it to be triggered quickly, before the brain just goes into autopilot and does what it usually does.

Exercises that strengthen and train the frontal lobe are particularly effective when it comes to improving your ability to respond adequately to impulses. The exercises in this chapter stimulate the relevant areas of the frontal lobe and allow you to process stimuli related to your interoceptive awareness, such as feelings of hunger or thirst, in a more differentiated, more appropriate and more effective way, giving you more control over your impulses.

Saccades – quick horizontal eye movements

One simple and easy way to activate the frontal lobe and the posterior section of the insular cortex is to do horizontal eye movements called saccades. The initiation and neuronal organisation of this movement takes place in the frontal fields of the eye, which are part of the frontal lobe and are in close proximity to the area that is jointly responsible for our ability to inhibit impulses. Because they are often supplied by the same blood vessels, parts of the brain that are close to one another each have an impact on the other’s activity levels. If you activate the frontal fields of the eye by jumping between different visual targets, you stimulate and increase the blood supply to the part of the frontal lobe that is responsible for suppressing impulses. Stopping the movement of the eye when it lands on the visual target is coordinated by the opposite cerebellum. This reports the precision of the eye movements directly to the frontal lobe, prompting it to optimise the movements if necessary. This communication forces the frontal lobe to work harder, meaning that it is activated both directly by triggering the eye movements and indirectly by stopping the eyes on the target. The posterior section of the insular cortex in particular is stimulated by the movement of the eyes. Increasing the activity level of the posterior section of the insular cortex helps you to reduce stress and regulate pain more effectively.

1. Stand up straight with your feet hip-width apart. Lengthen your spine but keep it nice and relaxed. Allow your breath to flow smoothly and evenly. Lift your arms up to eye height, without bending your elbows and with your thumbs pointing to the ceiling. Focus both eyes on your right thumb.

2. For a duration of 30 to 90 seconds, switch your focus to and fro between your right and left thumb. Make sure that your head stays still.

Anti-saccades – a special type of eye movement

Probably the most effective eye exercises for activating the exact region of the frontal lobe that suppresses impulses are what we call anti-saccades. This exercise is about suppressing an impulse generated by a visual stimulus and instead performing the opposite action. As you have already seen, every time you are forced to suppress an impulse – i.e., control your response to a stimulus – your frontal lobe becomes more active. The visual system is designed in such a way that your eyes reflexively jump to an object as soon as you notice a conspicuous movement in your peripheral vision. This allows you to identify what the object is and whether or not it poses a threat. This exercise requires you to suppress your natural and deeply ingrained instinct to look at the visual stimulus. So, you receive a visual stimulus, suppress your natural response to it and instead move your focus away from the stimulus. This special type of eye movement intensely activates areas of the brain that are involved in impulse control. The exercise also requires a lot more focus and attention than the saccades and thus also activates the anterior section of your insular cortex. Anti-saccades are therefore a useful and effective means of activating this important part of the insular cortex, which has a positive impact on your emotional regulation. All you need for this fun and extremely effective exercise is a training partner.

1. Stand up straight with your feet hip-width apart. Lengthen your spine but keep it nice and relaxed. Allow your breath to flow smoothly and evenly. Have your training partner stand about a metre and a half away from you with their arms outstretched at eye height. First, rest your gaze on your partner’s forehead or, depending on how tall they are, their chin.

2. Your training partner will now begin to make a rocking or waving motion with their index and middle fingers on one hand, which you should only notice in your peripheral vision, as your focus is still on their forehead or chin.

3. As soon as you notice the finger movement, switch your focus away from the moving fingers to your training partner’s other hand.

4. From there, return your gaze to your partner’s forehead or chin. Carry out this exercise for 60 to 90 seconds. It’s important that your training partner keeps switching hands in an unpredictable sequence. This ensures you have to stay focused the whole time you’re doing the eye exercise.

‘Dual tasking’ brain training exercises

Another fun way to activate the frontal lobe is to build counting exercises or specific brain-training exercises into your training or your daily routine. You can do these while carrying out other simple activities such as walking, jogging, climbing stairs, washing up or having a shower. By combining elements of movement and attention, these exercises stimulate the frontal lobe as well as the front and posterior sections of the insular cortex, and therefore improve your interoceptive awareness, as well as your general sense of wellbeing and your fitness levels.

Counting backwards

While doing an activity of your choice, start to count backwards from 100 in increments of 7. So, you will be saying aloud, ‘100’, ‘93’, ‘86’, and so on. It’s important that you keep doing the activity as well as you can while counting. At first, you can try this exercise simply while walking, and then build up to more complex activities.

Every other month
While doing an activity of your choice, start listing the months from January to December. The crucial trick is only to say every other month aloud. So, you would say ‘January’ aloud, then think ‘February’ in your head, then say ‘March’ and then think ‘April’, and so on. As with the counting exercise, it’s important that you keep doing the activity as well as you can. As with the anti-saccades (pages 58–59), this exercise requires you to control and suppress your impulses – in this case, the impulse to say every month in the sequence aloud. In this way, the exercise directly addresses the important parts of the frontal lobe.