Stress: a defense system
When considering lifestyle, we often tend to measure ourselves with tangible values: weight, pressure, waist circumference, cholesterol value, etc.
There is a detail that is often overlooked but plays an important role in our health: stress.
Physiologically, the meaning of stress is beautiful: it is our shield of Captain America. It consists of that neuronal activation that allows us to react and flee in the face of a danger.
This reaction brings about a change in the activation of the peripheral nervous system.
The perception of this stimulus warns our limbic system. This part of the brain is the seat of our ancestral emotions. From here the message passes through the hypothalamic-pituitary axis reaching the glands located above the kidneys (adrenals) that produce adrenaline. Adrenaline activates the various responses of the autonomic nervous system that allow escape. In the event that the stressful state persists, the hypothalamus sends the production of cortisol which maintains the state of alert.
After the complete dismissal of the stressful situation, the hypothalamus activates the parasympathetic nervous system to inhibit the response to stress.
The so-called “Fight and Run” reaction is an ancestral reaction that allows us to react during situations deemed and perceived as perilous.
In practice, in front of a danger, we react by running away and increasing muscle capacity. Thus cortisol acts as a catabolic hormone (from the Greek “demolish”).
That is, it splits muscle proteins producing glucose from amino acids, or the small bricks that make them up. In this way he guarantees the escape by paying with our reservations the possibility of bringing the derrière to safety.
It is called “diabetes hormone” because it increases blood sugar to cope with the rapid use of energy resources to ensure the functioning of the muscles and vital organs, in particular the brain whose only fuel is glucose. At the same time it limits the immune, digestive and reproductive systems as they are not considered indispensable to safeguard as all energies are concentrated on preserving life.
Nowadays cortisol is demonized as “the hormone that makes you fat”. As we have seen, its function is vital and allows you to take the skin at home, but unfortunately our lives are constantly exposed to important stress levels, both for the multitude of stimuli we have, and for the increasingly widespread inability to take the distances in relation to the events that dot our days.
All this to say two important things:
- The perception of stress, whether acute or chronic, is subjective and depends on personal experiences (ie on previous traumas), as well as on the genetic makeup
- Daily activities that appear simple to us, but which are difficult to deal with in our hearts, act as stressogenic stimuli.
 Selye H, The stress of life , 1956
How to act on our perception?
In fact, it is precisely from Buddhism, yoga and Hinduism that it draws inspiration; but meditating does not necessarily mean sitting on an orange cushion on the peaks of the Himalayas.
Ab initio was a practice closely related to the inner search for God. Then it was found that there was an improvement in the state of health as a side effect.
In recent decades, scientific research has demonstrated the effectiveness of mediation thanks to neuroimaging studies. These are studies that evaluate brain activity in progress, through markers that bind to neurons, evaluate the size of a specific brain area and how it reacts.
What is meditation?
attention without judgment at the present moment.
History and different cultures present different forms of meditation: mindfulness (literally fullness of mind) originates from Buddhist practice.
The definition includes the Buddhist concept of equanimity: that is, that serenity of mind that occurs in taking a position or judgment.
In its practice, it requires to regulate attention on thoughts, emotions, posture, physical sensations to stay focused on imminent sensations.
The goal is to live all the aforementioned with openness and above all with acceptance. In English it is expressed with the word acceptance, in Italian I would prefer to define it as “welcoming”.
I like to visualize it as the volume knob of an old stereo: it lowers the audible volume, which symbolizes all the external and internal physical sensations, to increase synchronization with the self.
 The neuroscience of mindfulness meditation . Yi-Yuan Tang et al. Nature reviews, April 2015
Which brain areas are affected?
During the state of meditation it has been seen that there are 3 areas in which meditation performs its greatest action:
- The caudate nucleus which, together with the putamen, plays a role to disengage from irrelevant information, allowing the meditative state to be achieved and maintained.
- The para-hippocampus which controls the flow of thoughts and stops the wandering of thought.
- The middle pre-frontal cortex that supports self-awareness during meditation.
In addition to these 3 main ones, there is the activation of:
- Fronto-polar cortex that is supposed to aid in transverse attention
- Sensory and insular cortex, which relate to body awareness
- The hippocampus, which deals with the storage processes
- Cortex of the cingulate-anterior of the middle cingulum and the orbito-fronatal cortex are airways predisposed to the regulation of emotions
- The upper longitudinal beam and the corpus callosum, involved in communication between the 2 hemispheres, right and left.
Although many studies have been done to understand which areas are affected by meditation, unfortunately our knowledge still remains at a rather superficial level.
Future studies are awaited to understand how the change in neuronal activation leads to well-being and manages to change behavior. 3
 Neural correlates of establishing, maintaining and switching brain states. Tang YY et al. Trends Cogn 2012
So what are the benefits?
- Warning (alerting): promptness in reactions for an imminent stimulus. It includes a tonic result, that is, vigilance, and phase results (i.e. due to changes in warning signals and objectives).
- Orientation: the selection of specific stimuli from multiple sensory stimuli.
- Conflict monitoring (Monitoring): monitoring and resolution of conflicts between stones in different neuronal areas, what is called executive attention.
Depending on the type of activity we are carrying out, participation in one or more components may be requested simultaneously.
Staying focused on a task for a long time requires the “warning” component for vigilance, which is the Orientation for selecting stimuli from different sensory stimuli.
The measure of attention can be calculated through the Attention Network Test (ANT).
This test was also used to evaluate the benefits of meditation. Several studies have confirmed an increase in executive attention and orientation already after 5 days of practice, for 20 minutes a day.
In long-term training (from months to years of practice) there is also an increase in the alerting component.
The brain region that seems to be most involved between meditation and increased attention is the anterior cortical girdle. It eliminates unnecessary stimuli for the information flow it is processing. In other words, keep your attention on what you are reading even if the notifications arrive on the phone: it won’t be wonderful!
Another region that appears affected by the practice of mindfulness meditation is the pre-frontal dorsolateral cortex.
This area is involved in the executive process for carrying out orderly and fluid actions, for memorizing and initiative.
It is not yet clear how different types of meditation can act on the different components of attention. Studies show changes in the aforementioned areas but it has not been understood yet how these changes increase the attention performance. 3
 Does mindfulness training improving cognitive abilities? A systematic review of neuropsychological findings. Chiesa et al. Clin. Psychol. Rev 2011
Regulation of emotions
Some circuits through which this adjustment is made have been proposed.
- Reduction of emotional interference in unpleasant stimuli
- Decreases physiological reactivity by easily returning to baseline after a stress-forming film.
- It decreases the intensity and frequency of the negative effect by increasing the positive mood.
The neuroimaging studies show that this is made possible by a strengthening of the control mechanisms of the prefronatle congnitive area and by the regulation of the activity of the processing areas such as the amygdala, reporting once again to welcome and accept the present moment. Without judgment.
In conclusion, it is true … very little is known of scientifically proven, which makes us understand why meditation is such a beneficial practice.
Although it has existed for thousands of years, I find that its diffusion today is made necessary by our hectic and chaotic lifestyle.
But as the Bible says “there is nothing new under the sun“, the lives of our ancestors are also likely to be differently stressful.
Meditation is therefore one of the mechanisms through which we seek balance and well-being.
Why not try?
If you had already integrated it into your daily routine, I would be grateful if you could spend 2 minutes mindfully, to tell the benefits it has brought you.
 Orthner et al. Mindfulness meditation and reduced emotional interferenceon a cognitive task. Motiv. Emott 2007
 Goleman et al. Meditation as an intervention in stress reactivity. J Consult. Clin Psychol 1976
 Ding X et al. Improving creativity performanceby short-term meditation. Behav. Brain Funct. 2014
 Kabat-ZinnJ Full Catastrophe Living : using the Wisdom of your body and Mind to face stress. Pain and illness 1990