(10 min read)
In our house, the twenty-minutes before the school-run goes something like this:
(To my eldest) have you got your homework darling? Let me see. (To middle child) Have you done your teeth? Go and do your teeth. (To youngest) We haven’t got time to play with Play-Doh, darling, we have to get into the car. Where is your homework? The toothbrush is still in the bathroom, where it always lives. Please don’t put stickers on the dog. But you haven’t finished this – quick do it now! Why are you playing Lego? GO UPSTAIRS AND DO YOUR TEETH! Get a pencil and WRITE THE ANSWERS! DON’T go outside in tights! Its wet! Then use a pencil sharpener! WHY HAVEN’T YOU DONE YOUR TEETH? And while you’re up there, can you grab another pair of tights? Use a pen then!
It goes on.
I wish we could float out of the door on a cloud of serenity, teeth gleaming, hair brushed and seatbelts clicking into place in perfect synchronicity like the cogs in a swiss watch. I’m sure some people do. I’d like to meet them.
This type of stress is mild, and short-lived. And on the whole, harmless.
Short term or mild stress can actually enhance memory formation, particularly if it is emotional. Think of an old childhood memory, and the chances are its emotional.
Intense or long-term stress is different. It negatively affects how children learn and perform at school (and us at work). It’s the sort of stress felt by a child who’s scared of the chemistry teacher, particularly today when they haven’t done their homework, or who is worried about the people who posted nasty comments on their social media page.
The Stress Response
What’s going on in our brains when we start to feel overwhelmed or panicky? Understanding the process helps when your boss sends us an email IN CAPITALS or the car in front is driving you mad – it’s simply a response generated by your brain, based on your past experiences. It is easier to calm down, when you recognise it for what it is.
The amygdala has become a real buzz word in the ‘Wellness’ movement. Actually, there are two amygdalae, one in each side of our brain. They’re small, almond-shaped[1] structures that influence which neurotransmitters and hormones are released into our central nervous system.
One of their most important jobs is to perceive emotion. This includes when to panic, a process activated either via the fast track or the slow track. To oversimplify what is actually quite a complex process, it goes something like this:
The slow track passes through the cortex – the outer, thinking part of the brain. We have time to think about it first. If we are healthy and calm, we consciously tell ourselves that we don’t need to be fearful. However, if you suffer from irrational fears your thoughts can actually feed the fear.
The fast track happens in under a second: the fight or flight response. Our amygdalae hit the panic button before the information travels to the cortex – before we’re aware of the cause. The amygdalae trigger the release of norepinephrine, sending impulses to our adrenal glands which release adrenaline into the blood. Breathing, blood pressure and heart rate increase. Muscles prime themselves for action, digestion shuts down, saliva-flow stops. If it’s really bad, the muscles in the bladder relax to conserve glucose.
If we need to stay alert for longer than the fight or flight situation, the effect is prolonged by the release of cortisol. It keeps us primed for action.
Chronic stress
What if stress becomes prolonged? Does it matter?
Yes. Because long-term stress can cause long-term change and damage to our brains. Interestingly, epigenetic forces (see Plasticity article) are at play here too: this is when the things that happen to us change how certain genes are expressed – and sometimes inherited.
There are three parts of the brain that particularly affect learning when we’re stressed: the amygdala, the hippocampus and the prefrontal cortex.
Amygdalae – the emotional centre
In a previous article, I wrote about brain plasticity – how experiences cause a change in how nerve cells connect/communicate with each other. Chronic stress can cause changes in the amygdalae’s circuitry.
For instance, when rats experience long-term stress, there is an increase in dendrite branching and spine density in the amygdalae: they become hypersensitive, firing off the fight-or-flight response more readily.
When the stress is removed, the rats continue to feel stressed. They remain hypervigilant and wary of anything that might be harmful.
When we experience repeated stress, our brains also adapt. We become more vigilant, more anxious, and remember horrible experiences more vividly. This is a great tactic to survive in stone-age, but not in 21st century life where most events are not life-threatening.
Hippocampus – learning and memory
Some parts of the brain bear the burden of high levels of the stress hormone cortisol more than others. In particular, a part called the hippocampus. This structure sits deep in the brain and plays a crucial role in learning and memory. It converts information in short-term to long-term memory. Its function is thus fundamental to how children perform at school – and us at work.
Chronic stress hampers the ways in which hippocampal neurons respond to information[i].
This is because the hippocampus has lots of cortisol receptors. In normal conditions it acts like a ‘stress thermostat’, shutting off cortisol production when it gets too high. When we’re chronically stressed, and cortisol has been sloshing round our system in excess or over a prolonged period, the hippocampus receptors simply shut down. The connections between nerve cells start to wither. Our emotions and thoughts become more rigid and simple – and so does our decision-making.
The hippocampus begins to atrophy, to waste away. We know this because when people suffering from stress-related disorders have their brains scanned, they have smaller hippocampi. This means our capacity for memory also diminishes.
Another effect of cortisol is to produce a neurotransmitter called glutamate. Initially, this helps us make more memory connections, and helped our ancestors remember frightening events or dangerous locations. But it also has the effect of making us remember, and dwell, on the things that stress us out –the scary chemistry teacher, the cyber bullies, an email.
Prefrontal cortex – for decision making
The prefrontal cortex is the part of the brain that makes us distinctly human. Its where decision-making, logic, emotional regulation and reasoning happen. The prefrontal cortex allows us to focus, so it’s a fairly fundamental part of the whole learning thing.
It can also provide top-down control over whether or not we respond to a situation with stress.
But, when stress is chronic, scientists now think that it impairs the prefrontal cortex’s functions. This affects other cognitive and homeostatic functions. One of these processes is decision making (have you ever found it much harder to decide when you’re stressed? Do you get acute indecision when there’s an impatient queue behind you at Pret –which coffee? Which size? Sprinkles?)
But seriously, people suffering from depression or PTSD can find it really hard to make a decision. And if it’s a big one (shall I move house? Quit my job? Re-train?) indecision can be crippling. When scientists scan their brains, they show volume reductions in several subregions of the prefrontal cortex.
This can, obviously, lead to changes in behaviour, such as hypoactivity (lethargy), an inability to focus and a preoccupation with worrying about things.
Essentially, we have evolved to be very sensitive to environmental stress. And in a world where we now bump up against stress on a daily basis, it’s not surprising it affects the way we behave and live.
Your experience?
As parents and educators, is stress a worrying part of your life? How do you deal with it? Please do share at drtorrancejenkins.co.uk. And if anyone has any tips for the school-run departure, I would love to know about it! (and whilst writing this a friend gave me an excellent school-run hack: always keep a set of toothbrushes downstairs. Boom!)
Next Question:
How do I help my child deal with stress? Some top tips to make life easier.
[1] ‘Amyugdalē’ is the ancient Greek word for almond, the shape of the amaygdalae in our brains.
[i] Groeneweg, F.L., Karst, H., de Kloet, E.R. and Joëls, M., 2011. Rapid non-genomic effects of corticosteroids through the membrane-associated MR and GR and their role in the central stress. J Endocrinol, 2, pp.153-167.