Stress & Threat

Stress is the body’s way of responding to a challenge. A low to moderate level of stress helps us become resourceful and get things done. This “good” stress provides us with the tools needed to meet the challenges we face on a daily basis. Too much stress, chronic stress, or “distress” damages the learning process and tears at body systems. Knowing how the brain and body's stress response works and how it affects learning should be enough motivation for teachers to eliminate stress and threat from the school environment. Classroom threat commonly involves stating an intent of punishment by delivering or withholding something. Threats used as a method of coercion can activate the stress/survival response and make learning difficult.

I've learned...

STRESS - Normal & New Normal

Stress can range from an increased state of feeling alert to feeling completely overwhelmed.
The stress response is why we’re all still here. It’s a reaction to a challenge. A little bit of stress is OK. It helps us to be productive and get things done. If you have a normal amount of stress you might have a stressful event, respond to it, recover then get back to normal. Distress is when the stress is elevated overtime. A person receives one hit right after another with no time to recover. There can be feelings of losing control. With no time for recovery, the mind and body begin to adapt to this stressful state. This becomes the new "normal." And it becomes very difficult to get back to the old "normal." If it lasts for too long (months) there’s damage to various body systems, damage to the brain, and learning/ memory will be impaired.

THE STRESS RESPONSE

The stress response is an instinctive built in process carried out by the brainstem and the sympathetic nervous system. Hormones released in succession (HPA Axis - explained later) prepare us to take physical action in response to a challenge.
The stress response allows us to react and adapt to challenges that we face. As humans have evolved those challenges have become different. We don’t have to run from wild animals and fight for our food like our ancestors. However, we still have the same response built into our bodies and brains. And it kicks into action whether or not a threat is real or perceived.
Think of stressful situations on a scale of 1 to 10. A 1 being something very minor that might get your attention and a 10 being something absolutely overwhelming. Being chased by a wild animal would definitely warrant a full-blown stress response and measure in at a 10. The problem is, in today's world some of the things that should really measure in at a 1 or 2 are causing the brain and body to react at a 10. Road rage would be a prime example.

UNDERSTANDING THE SEQUENCE OF EVENTS

The amygdala gets sensory information from our experiences via the thalamus and cortex. It assigns emotion to the experience (positive or negative - the brain does not distinguish between good and bad stress). All our experiences have an emotional content (from Blah.. This is boring or OH NO! RUN FOR YOUR LIFE! or Yipee This is Fun! Let's do it again!)
Our limbic system (thalamus, hypothalamus, basal ganglia, amygdala & hippocampus) processes emotion. The feelings initiate the release of neurotransmitters.
If the experience initiates the stress/survival response a message is sent to the adrenal gland to start releasing the hormones necessary to meet the challenge.
Epinephrine (AKA adrenaline) is pumped into the bloodstream.
Heart and breathing rates go up and the person begins to feel agitated.
A message is sent to the hypothalamus to send another message to the pituitary gland to activate another part of the adrenal gland to release cortisol. This relay of messages via chemicals is called the HPA axis.
The amygdala also signals the hippocampus to start recording memories related to the experience.
Another message is sent to the prefrontal cortex which has to decide whether or not a response is necessary – freeze, fly or flee?
This stress/survival reaction can be started by a perceived threat or a real threat. The threat doesn’t even have to be real for this to get started. An imagined threat can initiate a physical response.
Epinephrine increases heart rate, increases blood pressure, dilates bronchial tubes in the lungs to enable more oxygen to be carried to the muscles, and readies muscles for action (fighting or fleeing).
There can be increased muscle strength. There will be an increase in blood flow for more oxygen distribution to the heart, lungs, arms and legs (for the fighting and fleeing).
Blood vessels in the skin constrict to allow less bleeding in case of injury.
Endorphins are released so we will feel less pain, digestion shuts down, saliva stops flowing, and bladder muscles relax.
Norepinephrine and dopamine increase focus and attention so we can take care of the situation.
Epinephrine converts glycogen and fatty acids to glucose for the increased need for energy.
Cortisol signals the liver to make more glucose and release it into the bloodstream. It also blocks insulin receptors to organs unrelated to the flight or fight response. It starts building up energy stores by converting protein to glycogen and starts storing fat so it will have an energy store if needed for survival (again… for fighting and fleeing). The body becomes insulin resistant.

Good Stress (Enough To Get Things Done) & Bad Stress (Toxic or Chronic - Never-Ending)

When someone is suffering from chronic stress they are continually operating reactively from the survival centers of their brain and the sympathetic nervous system instead of the higher decision-making, problem solving areas.
They are in what is called an adjusted allostatic emotional state, and with no time for recovery between stressors they are unable to return to normal. They have a "new normal."
When the brain has time to recover, challenges can actually help the brain to grow in positive ways. But with no recovery time or when it is in a chronic state of stress it can have a very negative effect on the body and the brain. Read on...
The development of the frontal lobe will be limited. We will have a decreased capacity to decide what we want to focus on. This forces us to focus on survival, which makes learning difficult. We lose the ability to choose our focus.
Cell polarity decreases and more virus and bacteria are allowed to enter the cells. Our immune system becomes impaired.
The senses are on high alert and become hypersensitive to help with survival. Vision goes to the periphery - high alert!
There is a decrease of the uptake of proteins, which are the building blocks of nerve cell growth and dendritic branching. This makes remembering and learning things unrelated to whatever is causing the stress very difficult difficult. Learning is impaired.
During chronic stress, connections continue to be made in the amygdala that keep calling for more cortisol. The cortisol continues to signal for extra energy supplies but the energy doesn’t get burned the way it was intended (actual fighting or fleeing). With no place to go, these extra energy supplies get stored in the form of belly fat.
At the same time cortisol production is increased, the production of the calming neurotransmitter serotonin is being inhibited. Serotonin plays a role in sleep and with less of that, sleep patterns are interrupted. Now we have an overtired, chronically stressed individual who can't get the right amount of rest.
The amygdala actually gets stronger and begins marking everything inappropriately. Things that shouldn't be fearful are marked with fear (everything becomes a stressor), which can lead to anxiety, depression and declining cognitive skills.
Our brain uses about 1/5 of the body’s energy supply and is not able to store its own fuel. It has to have a continuous slow supply to keep working. Cortisol in healthful levels maintains a flow of glucose to make sure the brain is functioning well. But there’s not enough fuel for all neurons (all brain areas) to go to work at the same time. Glucose shifts to different brain areas based on current needs and demands. With chronic stress the HPA axis is the most needy and gets the attention. It gets the fuel supply to keep the system on alert while the decision-making, rational thinking part of the brain doesn’t get enough energy to function at its best. A little bit of cortisol helps with memory formation but when there is chronic stress, too much cortisol suppresses it. This limits the development of the frontal lobe.
Chronic stress creates a continued emotional strain and the body has to adapt physically. The adaptations include anxiety, depression, high blood pressure, low functioning immune system, heart problems, cancer, and negative changes in the brain.
Classroom threat can come from teachers and other students. Threat of any kind can create distress. Many classrooms rely on threat to control behavior. Lots of threat & anxiety = No New Learning.
When threat and fear are present, the brain will focus on safety and survival and hold off on any new learning. All the resources that could be used for new learning are being diverted to the part of the brain concerned with staying safe. It activates the fight or flight reaction and sends blood to the extremities which decreases blood flow to other areas - including the brain. When we are in an environment that is scary or threatening we can't think and learn as well as if we were feeling safe and secure. The brain will always check to make sure everything is safe first.
Immediate crisis = stress response = punching, hitting, yelling. Discipline problems are inappropriate expressions of emotion resulting from an innate biological response.
Ongoing stress = increased cortisol = stunted growth of dendrites in the area of the brain that stores factual memories. Chronic stress releases hormones that kill neurons in the area of the brain responsible for long-term memory formation. Who wants that?
Powerful stress hormones are released when life’s challenges become overwhelming. If they remain high for too long the results can be increased risk of heart disease, suppressed immune function, high blood pressure, and destroyed neurons in the hippocampus (which interferes with learning and recall). Stress contributes to impaired learning.
The brain needs feedback in order to learn. Lack of feedback contributes to higher stress levels. Feedback reduces uncertainty, increases coping skills, and decreases the stress response. It is most effective when immediate, specific versus general, involves choice, and is self-generated.

Use Movement & Exercise
As stated before, today we don’t have as much need for the stress response on a daily basis but we still have it, and it works in the same way. A stress trigger sets of a chain of neurotransmitters to signal different parts of the brain and body to react. Our ancestors needed this stress response in order to survive. They had to walk miles and miles, fight beasts and birds of prey, build shelters, hunt for meat, and forage for nuts and berries in order to eat and survive. The extra glucose, needed for extra energy, triggered by this built in stress response wasn’t stored. It was burned – used up by physical work, fighting, or fleeing. Clearly, our ancestors moved a lot more than we do today. We seem to be engineering movement right out of our lives. Why move when we can figure out how to make technology do it for us? Today, lions, tigers and bears, are not triggering our stress response; things that don’t require us to burn the extra glucose being produced are triggering it instead. The stress response is getting kicked into high gear by someone getting cut off in traffic, a disagreement with co-workers, having too much to do and not enough time to do it, verbal threats, a bad referee call, etc. And there we are... left with all that energy build up and no outlet for it. We don’t need to move as much to survive and on top of that, many people are consuming many more calories than needed on a daily basis. To make things even worse, when we are faced with a stressful event and our system calls for more glucose we crave foods that tend to be high in simple carbohydrates. By choosing to move more and make exercise part of our lifestyle we can positively manage this built in survival response. When we choose to use our bodies we can have a positive affect on our brains.

Because...
Exercise Actually Makes You Better Able to Handle Other Stressors.
Exercise is actually a form of stress. Neurons are broken down a bit with exercise much like muscles. Then they recover with rest. They actually change shape and abilities. The hippocampus records the context of our memories and the amygdala marks them with emotion. The prefrontal cortex has the ability to direct the hippocampus and can shut off the HPA access (relay of information and hormones that start the physical symptoms of the stress response) and that's how it can shut down the stress response.

This is how it works…

Glutamate, the signaling neurotransmitter between neurons in the hippocampus increases the speed of information processing and changes synapses so each time the message is sent it is smoother and faster. When the stress response starts cortisol, CRF (corticotropin releasing factor), and norepinephrine attach to cell receptors and there is an increased production of glutamate. In the beginning the stress response improves memory but only for things related to the survival. More proteins are made for more dendritic branches and receptors. These cells save the survival memory. If opportunities for other new learning (not related to survival) come along during a survival response they will have a hard time being saved and recalled.
This increase in cortisol makes it hard to learn something new. The hippocampus is busy with the stress and shuts everything else out. Increased levels of cortisol can also block memories that already exist making it hard to retrieve unrelated memories.
Getting regular exercise can have a positive effect on how the brain handles the stress response by making changes in the brain. Exercise actually raises the trigger point for the physical reaction of the built in stress response.
When extra energy is produced during the stress response it is absorbed into the mitochondria of cells and turned into ATP (Adenosine triphosphate – a usable form of fuel for cells). When this fuel is burned, waste products (free radicals) are produced. This waste needs to be cleaned up. It will do damage if left floating around in the body. Normally, our cells produce enzymes that do the clean up. Under toxic or chronic stress, the extra cortisol produced signals for more glutamate to be produced. But there is not enough ATP to keep up with the energy demand. The brain cells have to work without fuel and they die. Making a habit of regular exercise actually makes the body and brain better able to handle this situation. With regular exercise, the following things happen that have a positive effect on the stress response.
When you exercise more oxygen is carried throughout the body and brain to help make more ATP to fuel the working cells. Because exercise causes the cardiorespiratory system to adapt and become more efficient, every part of the body gets a better supply of oxygen and nutrients.
As during a stress response, during exercise, blood flow is shifted from the prefrontal cortex to the midbrain made up of the hippocampus and amygdala. So during exercise higher brain function is impaired. it’s what happens afterwards that is important for educators to understand so they can put that knowledge to work for increased learning, skill development and learning.

The Bodily Adaptations of Exercise

With regular exercise we get a more efficient circulatory system with more and bigger blood vessels, which results in more efficient blood flow to all body parts (including the brain). A better oxygenated brain works better.
Brain cells become able to use energy more efficiently. Exercise increases the number of insulin receptors, which results in stronger cells that use glucose more efficiently. With more insulin receptors, if there is a drop in glucose the cells can still get a little bit out of the bloodstream to keep going.
Intercellular energy production increases and neurons have enough fuel without a build up of waste (free radicals).
Exercise increases production of IGF1, which enables insulin to manage glucose levels better. Because it plays such an important role, more IGF-I results in increased LTP, neural plasticity, and neurogenesis.
Exercise lowers the resting tension of the muscle spindles. This results in less stress on the body and if the body is more relaxed the brain will be too.
Exercise results in a more efficient cardiovascular system. The hormone ANP is produced in the heart. ANP is the hormone that slows down and stops the HPA axis (the relay of hormones kicking off the bodily changes that happen with the survival/stress response). As your heart rate increases with exercise so does ANP. This adds to the ability to manage stress in a positive way.
Exercise increases the production of BDNF. BDNF increases antioxidants and protective proteins in the brain cells. It stimulates LTP (long term potentiation) and helps new nerve cells grow which strengthens the brain for stress.
Growth factors are produced in the brain and also produced by muscle contractions. When muscles contract both of these factors are released into the bloodstream traveling to the brain. These growth factors play important roles in stress, metabolism and memory. More is better.

How can I eliminate stress and threat from my classroom? How can I teach students the relationship between exercise and the stress response and promote healthy stress management practices?

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