Heart Rate and Breathing.  Brain and Body Connection – NeuroQuotient®

Heart rate, the rhythm of the heartbeat, is related to breathing. Knowing how it works helps us better understand the neuroscience of behaviour and have more resources to improve our well-being. We will see how the brain and the body are connected by the autonomic nervous system and we will give our opinion on two neuroscience articles.

Two summaries that we have read in Neuroscience News serve us as a starting point for writing this article. In it we will inquire into the connection between the brain and the body. Specifically, in the relationship between the brain, heart rate and breathing. Let us remember that the purpose of NeuroQuotient®  is to have more options for well-being from the knowledge of psychobiology and behavioural neuroscience.

The post is quite long. For a faster reading, we can follow the bold subtitles.

We start by looking at what the Neuroscience News abstracts are about.

Breathing and Fear

‘Breathing in through the nose activates the amygdala, the brain centre of fear’.

The first summary is from 2016. The title: Rhythm of Breathing Affects Memory and Fear. It is based on an original publication of Christina Zelano et al in The Journal of NeuroSecience: Nasal Respiration Entrains Human Limbic Oscillations and Modulates Cognitive Function.

Individuals identified a fearful face much more quickly if it appeared to them while breathing in than when breathing out. Furthermore, they were much better able to remember an object if it was presented while inhaling. This always happened when breathing through the nose, if they breathed through the mouth the effect disappeared.

They found a marked difference in the activity of the amygdala (limbic fear centre) and the hippocampus (memory centre) between inhalation and exhalation. The activity of the amygdala and hippocampus was greater when breathing in.

So, we see that breathing, and differently when inhaling and exhaling, influences the brain and human behaviour.

Let’s leave it here for now and see the other article.

Heart rate and depression

“With depression the heart rate is higher and at night its decrease is impaired’.

The other summary is more recent. September 2020. The title: Depression Risk Detected by Measuring Heart Rate Changes.

The original source was an interview to Dr Carmen Schiweck (Goethe University, Frankfurt), about a study that was going to be presented in the Virtual Congress of European College of Neuropsychopharmacology.

They studied two groups of 16 participants. One made up of people with depression and a control group with healthy people. Their heart rates were measured for 4 days and 3 nights. The depressed participants were then given ketamine or a placebo.

They found that participants with depression had a higher heart rate (10-15 beats per minute) and less variability, as previous research indicated. Normally, the heart rate is higher during the day and lower at night; with depression it seems that this nocturnal decrease in heart rate is impaired.

After ketamine treatment they found that both the heart rate and its variability of the previously depressed patients were much closer to the values of the control group.

We are not going to go into if ketamine can be a good treatment for depression. We simply keep the idea that the rhythm of the heartbeat has a close relationship with depression. Logically, it will also have it with the depression associated neuro behaviours.

Brain and body connection

“The autonomic nervous system, and the somatic nervous system, connect the brain and the body.”

To understand what has been said so far, it is necessary that we see the connection between the brain and the body.

The brain (encephalon and spinal cord) connects to the body through the peripheral nervous system (PNS) which consists of two components: the somatic nervous system (SNS) and the autonomic or vegetative nervous system (ANS).

The somatic NS receives information from the sensory organs and controls the movements of the skeletal muscles. But, for what we are dealing with, the relationship between brain and heart rate taking into account breathing, we will stay with the ANS (autonomic nervous system). The function of the ANS is to maintain the balance of the internal environment (homeostasis) by regulating automatically, the cardiovascular, respiratory, digestive, excretory and thermoregulatory mechanisms.

The ANS (autonomic nervous system) has two branches, the sympathetic and the parasympathetic

‘The sympathetic branch is involved in energy expenditure and stress. The parasympathetic branch participates in the recovery of energy and rest ‘.

The sympathetic branch is mainly related to activities associated with the expenditure of energy reserves stored in the body. Thus, the effects of sympathetic activity are more evident in situations of stress, exciting or fear, producing, among other changes, an increase in blood flow to skeletal muscles, stimulation of adrenaline secretion and, with it, a heart rate increase and, also, an increase in blood sugar levels.

The parasympathetic branch is related to activities involved in increasing the energy stored in the body, such as the activity of the digestive system.

In Table 1, we have some of the performances of the sympathetic and parasympathetic branches of the ANS. We see that while the sympathetic ANS accelerates the heart rate and dilates the bronchi, the parasympathetic NS has the opposite effect (it slows down the heart rate and makes ventilation difficult). Looking at the set of Table 1 we can understand that the sympathetic ANS is more involved in stress and energy expenditure and the parasympathetic in energy recovery and saving.

Organ Sympathetic branch parasympathetic branch
pupils dilation constriction
saliva inhibition stimulation
lungs ventilation relaxation makes ventilation difficult
heart accelerates heart rate slows the heart rate
stomach Inhibits digestion stimulates digestion
Table 1. Some actions on the organism of the sympathetic and parasympathetic branches of the ANS.


Full breathing cycles

So that we can better understand what we will discuss below, it is important that we remember how to do full breathing cycles.

Both in the practice of yoga, as in meditación, as in practicing relaxation techniques, they teach us to do full breathing cycles.

Complete breathing cycles consist of the following (Fig 1 serves us as a guide):

After thoroughly expelling the air from the lungs,

  1. We breathe in slowly and deeply, taking the air through the nose and bringing it to the lower part of the lungs. We notice how the abdomen is swelling.
  2. We continue to breathe in, bringing air to the upper part of the lungs. We notice how the chest swells.
  3. We begin to exhale, now in reverse order, first removing the air from the upper part of the lungs.
  4. We continue to remove the air from the abdominal part of the lungs.
  5. We start another cycle: inhaling (abdomen, chest), exhaling (chest, abdomen).

Let’s leave it here for now, then we get back to it.

full breathing
Figure 1. Full breathing cycle. Filling the lower part of the lungs (1), the upper part (2), letting the air out of the upper part (3) and the lower part (4).

Figure 1. Complete breathing cycle. Filling the lower part of the lungs (1), the upper part (2), letting the air out of the upper part (3) and the lower part (4).

Heart rate variability is continuous, not just between day and night.

‘When breathing in the heart speeds up and when exhaling it slows down’.

In the second summary that we quoted at the beginning (depression and heart rate), they told us that in people with depression the heart rate was higher. In addition, at night the rhythm of the heartbeat tends to drop and in people with depression it does so to a lesser extent.

But, is that the heart rate is not constant, it oscillates continuously! When taking our pulse to measure our heart rate, we count the number of beats in a minute. But, in this way, we are measuring an average value! Actually, the time interval between consecutive heartbeats is not kept constant.

It happens that when breathing in the heart speeds up and when exhaling the heart rate slows down. We can test this by doing a couple of cycles of full breathing while taking our pulse with our thumb on the wrist. We will see that as we breathe in, the time interval between consecutive beats shortens. On the contrary, when the air is released, the pulsations become more spaced.

A more accurate check of how the heart rate varies with breathing.

We can check that the heart rate fluctuates with respiration with the Doc Childre HeartMath Freeze-Framer application that we have been using since 2005. (In HeartMath you will now find more current applications for smartphones).

Freeze-Framer detects the heart pulse with a sensor placed on a finger (or on the earlobe). The computer application calculates the instantaneous heart rate from the time interval between every two consecutive beats.

We have measured the instantaneous heart rate for near 4 min while doing full breath cycles. In Fig 2, we see that the heart rate has been following an almost sinusoidal curve. In each cycle, the frequency has increased as breathing in and has decreased as exhaling.


continous heart rate
Figure 2. Heart rate with consecutive full breathing cycles. When you breathe in, the heartbeat rhythm increases and when you exhale it decreases.

Figure 2. Heart rate with consecutive full breath cycles. When you breathe in, the rhythm of the heartbeat increases and when you exhale it decreases.

During the time of the test, the average of the peaks of the curves was 77 heartbeats per second and the valleys were 65. The average heart rate was 71 beats per second. That is, if we had divided the total beats by time in minutes, the result would have been 71 heartbeats / second.

The rhythm of the heart and the autonomic nervous system

‘When breathing in, the sympathetic branch of the ANS accelerates the heartbeat rate and, when exhaling the parasympathetic branch slows it down’.

But there is something even more interesting. Let’s go back to Heartmath and Doc Childre et al. Specifically to the book ‘The Hearthmath Solution’ (HarperCollins Publishers, 2000).

They tell us that when we have an almost sinusoidal heart rate curve, like the one in Figure 2, it is because the sympathetic and parasympathetic branches of the ANS are in balance. The sympathetic branch accelerates the frequency of the heartbeats and the parasympathetic slows them down; one after the other and so on.

We cannot fail to introduce the principle of The HeartMarth Solutions technique. They explain that the variability of the almost sinusoidal heart rate (cardiac coherence) is achieved when we are in positive emotions such as appreciation, love and care for others. When we feel emotions such as frustration, anger, etc. the heart rate goes up and down irregularly, and a broken line is recorded.

In addition, for HeartMath, cardiac coherence and being in the zone are synonymous. In NeuroQuotient® we talked in another post about being in the Zone and Flow as similar terms.

But, for this article, the most important thing is that we can achieve and train cardiac coherence by practicing conscious full breathing as well.

A summary of what was seen,

Before going to the conclusions and seeing how we can take advantage of these ideas to improve our satisfaction and well-being, it is convenient that we collect a summary of what has been discussed so far. Just as headlines:

  1. Breathing in through the nose activates the amygdala, the brain centre of fear’.
  2. “With depression the heart rate is higher and at night its decrease is impaired’.
  3. “The autonomic nervous system, and the somatic nervous system, connect the brain and the body.”
  4. ‘The sympathetic branch of ANS is involved in energy expenditure and stress.
  5. The parasympathetic branch participates in the recovery of energy and rest ‘.
  6. The heart rate increases when breathing in and decreases when breathing out.
  7. When inhaling the sympathetic branch of the ANS is more active and when exhaling the parasympathetic branch works.

The understanding of neuroscience provided by NeuroQuotient® allows us to comment on the following:

In previous posts (about stress or the relationship between memory and behaviour) we said that when our brain perceives a threat signal, the amygdala is activated and then the stress fast track (sympathetic ANS). In this way we are ready to face the threat (fight) or run away (flight).

Now we see (point 1, previous section) that the reverse also happens. When we breathe in, the amygdala is activated … because we activate the sympathetic ANS.

Another thing. Considering what we have seen, we must think that the sympathetic ANS is more active during the day and the parasympathetic one at night. Going to point 2 above, it is not risky to think that, with depression (and even more so with anxiety) the heart rate is higher and decreases less at night due to a lack of efficiency of the parasympathetic ANS. And, yes, also because the sympathetic ANS is more active than it should be.

How can we take advantage of what we have learned?

The most important thing is that we see that not only the unconscious brain influences the body, but by directing the breath consciously, we can influence the heart rate and our emotional state.

With full breathing we can train, for example, the balance between the sympathetic ANS and parasympathetic ANS and the cardiac coherence. This balance between the two ANS branches should come naturally, but unfortunately, it tends to be more inclined towards the sympathetic branch.

Finally, there is something else that we have not gone into, but that will help us. We have seen that the heart rate accelerates more when inhaling and in the second stage of complete breathing (when filling the upper part of the lungs with air). This reminds us that when we breathe mainly with the chest, we tend to do it faster, the sympathetic ANS is more active and the heart rate is higher. For this reason, to relax, it is important to practice abdominal breathing.

By consciously breathing we can, for example, start with a few full breaths and then focus on getting air in and out mainly from the lower lungs. That is, practicing abdominal breathing.


Reducing stress or not increasing stress?

In this article we inquire ourselves about which option is better: reducing stress or not increasing it. Stress, or rather distress (when it is very high and persistent) is an evil of our time. Understanding its neurological fundations we will see that many times we exaggeratedly increase it with our own perception and interpretation of situations. Understanding the neuroscience of behavior we become aware that sometimes we are limiting ourselves. The NeuroQuotient® helps us to do it.

Frequently, we want to lower our stress

A few days ago, when preparing a coaching session, we saw that a person asked us to discuss about more techniques and exercises to reduce stress.

He said something like this: ‘I practice sports and meditation, but I’m not able to reduce my stress to an acceptable level. Quite the opposite, I think it is increasing ‘.

It’s clear that we are talking about ‘distress’, excessive stress, almost chronic stress. The one that manifests itself in a series of unpleasant bodily sensations and in difficulty to concentrate and rest. Either it is hard for us to sleep or we fall exhausted and after two or three hours we are with our eyes wide open.

Often the main source of stress is oneself

How do we cause or cause stress to increase?

Shortly after starting the session we asked to the person who wanted to reduce the stress: How do you do it to increase your stress?

We can measure the sensation of stress on a scale of 1 to 10. We consider 1 to 5 adequate, above 5 to 7 worrying and 8 to 10 serious. The 0 does not make sense, it is not a reasonable level, the day we achieve it we will not be at all.

Someone in a constant sense of stress of 8 or 9, doing regular coping exercises, it seems clear that they have an internal source of stress.

It is logical that in a fire, in an earthquake, in a terrorist attack, in the face of a loss, etc. we feel stressed. But the person of the example, neither the present, nor in the past, had any similar situation.

There was not present, what we used to call, a relevant external stressors. It just happened, as in many cases, that the main source of stress was internal. An external trigger could exist, but the own perception was very much important.

 What are the neurological bases of stress?

The brain system of threat or fear

To understand it better, let’s see what happens in the brain, and in the body, with stress.

Stress is born in the system of fear or threat. With animals we prefer to talk about threat and in humans of fear. Fear is an emotion, the result of the interpretation of the situations and the corresponding sensations.

Let’s start with the animals and quite the same will be valid for the human animal.

What is the purpose of the threat system?

Simply, the species survival based on minimizing damage and pain.

When the animal perceives with its senses a signal that, its species memory, indicates that it is a threat, it can respond in different ways: Fighting, if it can cope with it or flighting, if the threat is greater than its possibilities.

We leave aside a third option here: standing still, freezing, which we have already seen earlier, more associated with depression in humans.

At the center of the threat system are the amygdalae. The sensory signal reaches the basolateral zone of the amygdala and, from there, goes to the central zone that connects with the autonomic nervous system, activating the sympathetic branch and braking the parasympathetic branch.

The animal is ready to attack or flee! So much goes for both. Depends on what the memory indicates, the amygdalae are the same and what comes next, too.

The fast and slow pathways of stress. The autonomic nervous system and cortisol

The sympathetic branch of the autonomic nervous system secretes adrenaline (epinephrine) in the core of the adrenal glands. The adrenaline passes into the blood, increasing the heart rate, increasing blood pressure, dilatating the pupils, opening the bronchi, etc. This is the fast, immediate path of stress. The one that facilitates fighting or the flighting.

After about 10 minutes, the slow path of stress begins to work. That of glucocorticoids (cortisol in humans). Cortisol is secreted in the cortex of the adrenal glands. Mainly it serves to generate energy from the reserves of the body (fats and proteins)

The slow way replaces the lack of activity of the parasympathetic branch, whose function is to favor the recovery of energy with rest and digestion: lowering the heart rate, contracting the bronchi, closing the pupils, promoting salivation, etc.

We usually talk about sympathetic activation and we forget parasympathetic deactivation. But symptoms like dry mouth, difficulty breathing, digestive problems, eyes open at night, etc., are very frequent, right? These symptoms lead us to think that we need to lower our stress.

On the other hand, the slow pathway has few opportunities for activity in animals. At 10 minutes the gazelle or has fled the lion, or very bad for the gazelle. If only it were wounded and hidden, then corticosteroids would go into action to facilitate its recovery.

It is important to point out that between the basolateral and the central amygdala there are neurons interspersed with the neurotransmitter GABA that can stop the activation of the central amygdala. In the next article we will discuss methods of coping with stress “Stress management. Learn not to increase stress from neuroscience “, we will talk deeply about it.

And in the most human part? How do we influence the fear system?

What has been seen so far is valid for humans also. We have already introduced it when talking about the parasympathetic autonomic nervous system.

The difference is in the higher prevalence of the prefrontal cortex (PFC). With which we think and direct attention. The one that differentiates us in more or less extention from the other mammals.

Thanks to the PFC, humans do not distinguish between what we perceive, what we imagine or remember. That is, the signals that reach the amygdala often have internal origin or, at least, are interpreted by the PFC.

With high worry, self-demand and perfectionism (when all details are very important), with the interpretation of situations, we can focus on exaggerated dangers, which are only in our mind. We self-generate fear and start the ‘flighting’ side of the threat system. On the other hand, wanting to achieve very high and short-term results, we see obstacles in the way and put ourselves in a position of ‘fighting’ towards others.

Then, with attention and thought we may activate the central amygdala and the sympathetic nervous system and brake the parasympathetic one.

Also, when we put ourselves in ‘flighting’ mode we do not run away. Why run? There is no a lion by there.

And stress appears. Tachycardia and dilated pupils, in a continuous state of alertness (very active sympathetic system) and feelings of suffocation, dry mouth, difficulty sleeping, digestive problems (parasympathetic system slow down).

When stress is persistent, long-lasting, anxiety appears. With the fast and slow pathways (cortisol) permanently working.

By putting ourselves in a fighting position, we do release energy. This is why sport works to reduce stress.

Some humans with great tendency to ‘fight’, do not accumulate stress because they expel all of it. Great for them and worse for the people nearby.

But it is not usual. After all, the fight and flight brain pathways are the same.

What is our specific case? Do we need to reduce stress because we tend to increase it ourselves?

We imagine that now there is little doubt as to how stress is generated and that, in many cases, the main source may be internal. And that, in general, for good management rather than thinking about reducing stress, it is more efficient to try not to increase it.

It is important to emphasize that not all brains and human bodies are equally sensitive to stress. Consequently, not everyone has the same need to manage it, because we do not feel it with the same intensity. Some people are more resilient and are less affected by external stressors.

In those who do feel stress intensely, often an important error happens: We try to manage it with thought, with the PFC. And, then, being so aware of the body sensations and by worrying, the result is the opposite to the desired one.

Well, considering the neurological basis of stress, in the next article we will look for ideas to manage it. To not increase stress or to reduce stress.

But, always the first step is awareness. With NeuroQuotient it is easy to detect the greater or lesser level of stress, the greater or lesser resilience, the tendency to fight or to flight and find ways, new neuro behaviors, to manage stress. It is about developing self-leadership.



How to improve self-esteem and mood (from neuroscience).

We propose a way to improve self-esteem and mood. The knowledge of behavioral neuroscience that provides NeuroQuotient® helps us to do it. Although the article is aimed at psychologists and coaches, we can all take advantage of it. Self-esteem and mood are very low in depression. The strategy we propose is based on strengthening neuro behaviors opposed to those most characteristic of this disorder.

Continue reading “How to improve self-esteem and mood (from neuroscience).”

Psychology and neuroscience. Depression, visual example. (series psychology and psychiatry -1)

We explain that the connection between psychology and neuroscience is remarkable in NeuroQuotient®. Although it is little explicit on the web. The relationship exists since the design of the model. NeuroQuotient was born from the answer to the question: What are the brain systems involved in the most frequent psychological disorders? We will see a graphic example about depression.

Professional people of psychology tell us that they appreciate a great potential to apply NeuroQuotient® in psychology. However, they do not see it reflected on the web.

They make us notice that we focus a lot on coaching and leadership, forgetting the connection between psychology and neuroscience that they see that NeuroQuotient® brings.

We can do nothing but accept that they are right. In both comments. Actually, there are Certified psychologists in the neuro tool who are using it with remarkable success with their clients. And because the connection between psychology and neuroscience provided by NeuroQuotient® is very powerful (and simple) and it is not explicit on the web.
Continue reading “Psychology and neuroscience. Depression, visual example. (series psychology and psychiatry -1)”