Mindfulness of Stress

The stress reaction and mindfulness as an alternative response

brain regionsOne interesting source of evidence for the effectiveness of mindfulness is coming from the new field of brain science which has been enabled by functional magnetic resonance imaging scans (FMRI). Simply speaking, MRI brain scanning equipment has now become sufficiently sophisticated and sensitive to measure very subtle changes of neural activity in regions of the brain that are associated with having certain functions. A huge amount of data on the effects of mindfulness practice has been accumulated by studying the brain structures of long-term meditators.

 What follows is NOT something to stress about! – nor to work hard to commit to memory. Just a broad back-ground document combining what we are coming to know about brain function, the body-mind connection, and the predicament of the 21’st century human condition whereby we find our SELF (and it’s projects) can be our own worst enemy

The experience of Mindfulness practices offers us the insight that our Observing Self, or Witness Self, Aware Self can – on the other hand – function as our best friend!


The Hypothalamus links the nervous system to the endocrine system via the Pituitary gland (hypophysis). The Hypothalamus, is located below the thalamus, just above the brain stem. In humans, it is roughly the size of an almond.

The Hypothalamus regulates certain metabolic processes and other autonomic activities. It synthesises and secretes neuro-hormones, often called hypothalamic-releasing hormones, and these in turn stimulate or inhibit the secretion of pituitary hormones.

The Hypothalamus controls body temperature, hunger, thirst, circadian cycles.

The Pituitary gland, or Hypophysis, is an endocrine gland about the size of a pea that sits in a small, bony cavity at the base of the brain. The Pituitary gland secretes hormones regulating homeostasis, including trophic hormones that stimulate other endocrine glands. It is functionally connected to the Hypothalamus. The Amygdalae are almond-shaped groups of neurons located deep within the medial temporal lobes of the brain, shown in research to perform a primary role in the processing and memory of emotional reactions.

 The Stress Reaction

 Which is manifested through the sympathetic nervous system (SNS), has differential effects in several regions of the brain (see diagrams). Chronic stress, marked by hyper-activation of the SNS, has been shown to create and perpetuate several neuropsychological abnormalities and is a strongly associated contributor to the pathophysiology of Major Depression and Burn Out.

The Brain’s Response to Acute Stress

 In response to seeing the bear, a part of the brain called the Hypothalamic-Pituitary-Adrenal (HPA) system is activated (mind-body connection).

Release of Steroid Hormones and the Stress Hormone Cortisol:

the HPA systems trigger the production and release of steroid hormones (Glucocorticoids), including the primary stress hormone Cortisol. It is very important in activating systems throughout the body (including the heart, lungs, circulation, metabolism, immune systems, and skin) to deal quickly with the bear. Cortisol, however, also feeds back into the Hypothalamus and Hippocampus (feedback loop –> hyper-activation).

Release of Catecholamines: The HPA system also releases certain neurotransmitters (chemical messengers) called catecholamines, particularly: Dopamine, Norepinephrine, and Epinephrine (also called Adrenaline).

 Catecholamines activate an area inside the brain called the Amygdala, which appears to trigger an emotional response to a stressful event. In the case of the bear, this emotion is most likely fear.

Effects on Long and Short Term Memory: during the stressful event, Catecholamines also suppress activity in areas at the front of the brain concerned with short-term memory, concentration, inhibition, and rational thought. This sequence of mental events allows a person to react quickly, either to fight the bear or to flee from it. It also interferes with the ability to handle difficult social or intellectual tasks and behaviours during that time.

hippocampusAt the same time, neurotransmitters signal the Hippocampus (a nearby area in the brain) to store the emotionally loaded experience in long-term memory. In primitive times, this brain action would have been essential for survival, since longer-lasting memories of dangerous stimuli (such as the large bear) would be critical for avoiding such threats in the future. Evolutionarily speaking then, we – in a time when bears are now unlikely to leap out to surprise us – are all descended from ancestors who had learned to store these emotionally loaded experiences in long-term memory. Those, during the times of our ancestors, who didn’t develop this capacity as well had their procreative capacity interrupted by bears and other fearsome predators and situations and had fewer off-spring


Response by the Heart, Lungs, and Circulation to Acute Stress:

The stress response also affects the heart, lungs, and circulation. As the bear comes closer, the heart rate and blood pressure increase instantaneously. Breathing becomes rapid, and the lungs take in more oxygen.  The spleen discharges red and white blood cells, allowing the blood to transport more oxygen throughout the body. Blood flow may actually increase 300 – 400%, priming the muscles, lungs, and brain for added demands.

The Immune System’s Response to Acute Stress:

The effect on the immune system from confrontation with the bear is similar to organizing a defensive line of soldiers to potentially critical areas. The steroid hormones reduce the activity in parts of the immune system, so that specific infection fighters (including important white blood cells) or other immune molecules can be repositioned. These immune-boosting troops are sent to the body’s front lines where injury or infection is most likely to occur, such as the skin and the lymph nodes.

The Acute Response in the Mouth and Throat:

As the bear gets closer, fluids are diverted from nonessential locations, including the mouth. This causes dryness and difficulty in talking. In addition, stress can cause spasms of the throat muscles, making it difficult to swallow.

The Skin’s Response to Acute Stress:

The stress effect moves blood flow away from the skin to support the heart and muscle tissues. This also reduces blood loss in the event that the bear causes a wound. The physical effect is a cool, clammy, sweaty skin. The scalp also tightens so that the hair seems to stand up.

Metabolic Response to Acute Stress:

Stress shuts down digestive activity, a non-essential body function during short-term periods of hard physical work or crisis. Other indicators of the acute stress activation would be gastrointestinal problems (e.g. Diarrhoea), frequent urination, change in appetite etc.

THIS IS ALL GOOD STUFF when urgently readying yourself to ‘fight or flee” from a bear, or to ‘freeze’ to escape detection!


Long Term damage due to ongoing arousal

Up to know we’ve been talking of primitive times; of the body mind reaction to real life & death situations – and how evolutionary selection favoured the development of reactive systems when faced with danger to life and limb.

Fast forward now through human pre-history via the development of language acquisition, the huge growth of the frontal cortex, the development of complex social networks, and the development of individual infant human beings into the vast web of cultural expectations shaping the young adult and their emerging sense of “SELF”.

“SELF” is a complex psychological construction –  a kind of ‘virtual identity’ which comes with our advanced cognitive abilities – enabling us to think about, reflect upon and judge our sense of “SELF”.

At the primitive, reptilian levels of brain functioning where the fight, flight, freeze reactions are triggered a threat to the survival of life and limb is virtually  indistinguishable from a threat to the survival the broad range of “SELF” projects such as: self-esteem, self-confidence, self-worth, status, reputation, group affiliation etc. Hence, an incident which is perceived a threat to these ‘SELF PROJECTS’ can trigger these bodily reactions described above. To make matters MUCH worse, our tendency to worry about imaginary future events, or to ruminate upon past events can also trigger and re-trigger these mechanisms (even in the present time absence of any such threats)

And – as cream on this very toxic cake – whereas in the primitive situation, fighting or fleeing from the bear would allow for constructive use and discharge of the stress toxins, in the case of the contemporary social/relational challenges which trigger us then:

a) there is rarely the call for strenuous, emergency physical activity, and

b) it is often considered shameful to allow for the natural shaking, sweating, shouting, crying methods our bodies do have from ancient times to help quickly discharge excess stress toxins.

Paradoxically then, our SELF PROJECTS (for eg. self-esteem) actively repress these natural mechanisms (for eg. I would have died with embarrassment!)  These toxins become stored in the muscles, body tissues and body organs and there is a build up over time leading to:

damageareabrainSickness behaviour: fatigue, lack of energy and motivation, sleep disorder (reduced slow wave sleep, early or frequent wakening), appetite disruption, Serotonin depletion – anhedonia (depression), immune suppression = frequent illness/infections, thyroid/endocrine burnout, obesity/diabetes, autoimmune disorders (chronic fatigue, psoriasis, lupus, fibromyalgia, chronic pain, chemical sensitivity), high blood pressure, infertility etc.

 Hypercortisolemia: Cortisol is a toxic substance if it is long term in our system. It impairs brain regions, suppresses secondary immunity, over-activates the Amygdala (fear/negativity), the Adrenals (burn-out / weight-gain), decreases neural branching and building of new neurons (stuck in old fearful thinking), causes atrophy of the Hippocampus (which can produce 30 000 new cells daily, but not if too high levels of cortisol are present in our system) – impairing of hyppocampal memory (spatial navigation, autobiographical memory: no memory or impaired memory). No new cells, means no ability to form new association/neuro-pathways (new ways of thinking). Impairment of Cingulate (inability to concentrate) and of Prefrontal Cortex (executive function, decision making).

Chronic Stress strengthens negative networks and weakens positive ones; it also prevents creation of new neural connections!

And the GOOD NEWS:

Mindfulness can reverse the symptoms of Chronic Stress Reaction

  • Indentify your cognitive ‘distortions’ – conscious awareness.
  • Notice when you are in a toxic ruminative spiral
  • Indentify the fact that the imagined ‘threat’ is only a thought.
  • Sit with what ‘is’ – I am ok, here and now.
  • Appraise your internal resources – focus & acting upon ‘I what I can do’.
  • Over time, re-setting the amygdala trigger. Using the higher functions of the frontal cortex to over-ride the hair trigger sensitivity of the reptilian brain to perceived threats to the SELF-PROJECTS