The Stress Response is that set of physiological processes engaged when we face a challenging stimulus — a stressor. The Stress Response is commonly known as the Fight-or-Flight Response.(1)
The stress hormones that are released energize your body to deal with the challenge. The stressor doesn’t have to be a sudden physical challenge, like facing a growling grizzly bear. It could be a project at work. (Many projects span months and even years.) Since it’s winter now, the stressor can be the cold or having to walk on icy sidewalks.
The stress response is proportional to the stressor, that is, the response is geared to what is needed to deal with a particular stressor. The same processes are involved for all stressors, for all challenges, but to different degrees. For example, our response to a physical attack is different than our response to being out in cold weather.
There are two routes that end with the release of the hormones adrenaline and cortisol.(2)
The faster route — the SAM System — gets adrenaline released, as shown in red above. The slower but longer-lasting route — the HPA Axis (shown in purple) — results in both cortisol and adrenaline being released.
The SAM System is designed to meet urgent, immediate needs. When the stressor stops, the SAM System also stops. Since adrenaline is quickly absorbed, the effects of the SAM System don’t linger. That’s not the case with the HPA Axis, because it is part of our regular, homeostasis maintaining mechanisms. The effects of the HPA Axis linger.
In the Stress Response, priority is given to your brain and to your major muscles which both need more energy, i.e., more oxygen and glucose. To get oxygen, you breathe deeper and faster to get more oxygen into your blood, and your heart pumps blood faster to get that oxygen out. To get glucose, the glycogen stored in your liver is broken down; the fat stored in fat cells is released so the fat can be broken down into glucose. This means higher blood sugar levels and higher fat levels in your blood. As well, your pupils dilate so you can get more visual input. Your attention narrows. While this allows you to focus on the stressor and what must be done to deal with it, you can miss other important things that are going on.
When you are cold, blood returning to the heart is diverted from veins near the surface to veins deeper inside the body to minimize heat loss. Heat is generated when you shiver: your muscles move (shivering) which increases the burning of body fat and sugars, so you get warmer.
Stress Affects Our Language Behaviour
Stress changes the way we speak. It changes how and where we pay attention. It affects our memory and ability to recall things. It interferes with our reasoning and decision-making. Some of the effects are:
- We breathe faster, deeper and stronger, so more air is forced through the folds of our vocal cords. That makes our voice louder.
- We have lots of energy. Our voice has a jackhammer-like quality to it because of all the extra stresses. (No pun intended.)
- Our muscles are ready for action. The muscles controlling our vocal folds contract, pulling them tighter. That raises the pitch of our voice. And our voice get an “edge” to it.
- We stumble when we speak. Many of our words stay on the tips of our tongues. We don’t quickly find the words we want to use.
- Our attention narrows so we can focus on what’s bugging us. We end up missing a lot of social cues and many non-verbal signals. We don’t pay as much attention to the other person, which makes them feel not-safe.
- We stumble when we speak. Many of our words stay on the tips of our tongues. We don’t quickly find the words we want to use.
Here we are, under stress — and we need to talk with someone. We’re focussed on what’s bugging us, so we miss a lot of social cues and many non-verbal signals, and we won’t really be paying much attention to the person we’re speaking to. And when we do speak, we’re loud, and our voices are higher and have an “edge” to them. These are all signals the other person’s brain will recognize as a threat since our brains are wired to recognize a loud sound as danger, especially a sudden loud sound. They will hear the loud, “edgy” voice as a signal of danger, and their HPA Axis and SAM System will jump into action. While we’re focussed on what’s bugging us, they’ll be focussed on their own safety. Both of us will miss all kinds of social and facial cues, and our language skills will be less than normal. Not a particularly good situation. And it gets worse.
Interesting discoveries have been made about how cortisol affects our brains. Scans of post-traumatic stress disorder (PTSD) patients show hippocampal damage as well as increased activity in the ventral anterior cingulate gyrus and right amygdaloid complex and decreased activity in Broca’s Area.(3) These are key areas for attention, depression, fear, and language.
Broca’s Area is important for speech, recalling what words mean, and retrieving verbal information from long-term memory storage. Lower the level of activity in Broca’s Area, and you lower not only your ability to put your thoughts into sentences and to speak those sentences, you also lower your ability to understand what others are saying. A decrease in activity in the hippocampus makes this worse, because the hippocampus is key to memory storage and retrieval.
There is a lot of research showing that cortisol hampers our ability to think by dampening activity in the frontal lobes. (4)
It’s no surprise that we misunderstand what others are saying when we’re under stress and that we don’t express ourselves very well.
Notes:
- Dr. Walter B. Cannon, M.D., a Harvard physiologist, conducted pioneering research in the early part of the 20th century in homeostasis and in the fight-or-flight response (a name given many years after his initial research).
- While other hormones and neurotransmitters are released, I will briefly describe adrenaline and cortisol.
- H.G. Prigerson, M. Narayan, M. Slimack, L.C. Beery and S.C. Jacobs, “Pathways to traumatic stress syndromes”, (1998) 11 Current Opinion in Psychiatry 11 149-152 at p. 151 citing L.M. Shin, S.M. Kosslyn, R.J. RMcNally, N.M. Alpert, W.L. Thompson, S.L. Rauch et al, “Visual imagery and perception in post-traumatic stress disorder: A positron emission tomographic investigation”, (1997) 54 Archives of General Psychiatry 233-241.
- A web search of “‘frontal lobe’ cortisol” will yield many studies. A good source for understanding how stress affects our brains is J. Douglas Bremner’s book, Does Stress Damage the Brain? Understanding Trauma-Related Disorders from a Mind-Body Perspective (New York: W. W. Norton & Company, Inc., 2005) found at amazon.com at https://amzn.to/38hgH4A
