Mechanics of eustress
This article by Dr Piotr Wozniak is part of SuperMemo Guru series on memory, learning, creativity, and problem solving.
Value of stress
Eustress is a beneficial variety of stress that may be perceived as pleasurable. Eustress occurs when well-chosen challenges get resolved productively (e.g. a school test), or where major stressors are taken away (e.g. roller coaster ride).
Eustress increases learning, it adds to the pleasure of life, and improves stress resilience. It can be modelled as short-lasting acute stress followed by reward.
Stress plays an important role in learning and exploration. While exploring a branch of knowledge for pleasure, the degree of stress associated with the process may be unnoticeable and perfectly masked by the pleasure of learning.
However, when interacting with the environment, we often need to learn things that ensure survival. Some of that learning may provide beneficial brushes with death that, in the long run, make sure that we can maximize exploration without suffering death or injuries.
The algorithm associated with exploration involves problem valuation network, and stress as a memory sealant.
Figure: Goldilocks effect in problem valuation: Harder problems are more rewarding, but are less likely to be solved. This determines optimum difficulty we look for. The expected reward will then be evaluated in the light of execution costs. Proficient problem solvers are good at spotting problems that maximize the reward. Children are quickly bored with easy games. They also give up games that go beyond their level. They naturally oscillate around games that provide maximum reward, which comes somewhere in the middle of the difficulty range. The same mechanisms work for children, adults or problem solving animals
Stress in exploration
When a healthy child or animal is faced with an exploration obstacle, e.g. a raging river, and a valuable exploration target, e.g. tree ripe with rich fruit load on the other river bank, the exploration algorithm will lead the explorer to the ultimate success (or decision to withdraw).
Most fears are a result of the re-conceptualization of negative experience. A newborn may be scared with noises, if noises are associated with other stimuli (e.g. abusive parent), those stimuli alone may soon cause fear through conditioning. If the fear is reinforced with pain or other noxious experiences, the fear will grow in potency.
A little baby is not inherently afraid of spiders, dogs, speeding cars, or even heights. All fears associated with dogs and cars are shaped by experience. In all likelihood, by the time of serious exploration, a raging river will be associated with a degree of healthy apprehension.
The image of a fruity tree will provoke ideation of a traversal of the river. This will induce stress (a fear response). However, if benefits are high enough, and the fear low enough, the animal may attempt a traversal. After a step into the water, it can recompute, retract, regroup, and reconsolidate. Perhaps during a night, a nightmarish dream will help establish better understanding of the threat. The algorithm will keep iterating until the ultimate success, or the ultimate decision: the river carries too high a probability of death. In each iteration, the entry to water will be more expertly and may allow of deeper exploration of safer spots. The survival tricks for swimming, and backtracking will be learned on the way. The productive progression into the river will likely feel good even without the ultimate fruit reward. That feeling is the beneficial eustress that makes memories of traversal indelible. Just a few traversals can seal the skill for life. Each major error and brush with death will result in acute stress that will resolve over sleep, or re-conceptualize into a fear that may close the river for life, or until a bigger fruit tree appears as a magnified attraction. It is all up to the problem valuation network to dose obstacles optimally, to dose stress optimally, to maximize the possibility of success. Unconstrained self-control is essential for productive exploration. See: Optimization of behavioral spaces in development.
Optimum stress
Problem valuation network computes the estimate of costs in problem solving. In exploration, some of the costs involve the risk of injury or loss of life. Those are translated to fears that form part of the input in the network. Fears contribute to the level of stress. Self-directed development is essential for developing a healthy mind free of fears and phobias. It is the problem valuation network that will optimally balance the degree of acceptable fear that can be balanced with reward that will provide a healthy system of estimates of threats in the environment in balance with a set of behaviors that act as countermeasures. A well-balanced system of threat evaluation is responsible for stoicism and optimism. When development is not self-directed, when risks are not self-dosed, and the output from the problem valuation network is overridden, we risk overdosing fears that may leads to anxieties, phobias and even depression. The source of fears may be unexpected and unpredictable. A child who has found its own acceptable interpretation of own natural death may become fearful of concepts such as galactic collisions, red-giant sun, black holes, or heat death. This contrast shows that unlikely threats may contribute to anxieties that are not associated with imminent threats.
Another way of looking at optimum dosage of stress is the concept of hormesis or a similar function that explains the existence of the optimum push zone in development.
Chronic stress
Many a teacher or parent will claim falsely that stress prepares you for adult life. This statement without qualification might justify scaring newborns in the cradle, or exposing toddlers to horror movies. The distinction is simple: self-dosed eustress is beneficial, chronic stress is deadly.
When the school systems sets kids in front of obstacles that increase at excessive increments, or provide a looming threat, e.g. major life-or-death exam on a remote horizon, the stress that should help learning may turn into a chronic stress that organically destroys the brain. The destruction comes from bathing the brain in an increased level of stress hormones, and from the fact that chronic stress invades sleep, leads to insomnia, or phase shift disorders.
The exact same process occurs in adult life, esp. in adults whose stress resilience has been ruined at school. Once the adult enters the corporate world, or life in a political system that limits their personal freedom, they may never fully be able to learn how to use challenges of the day to build stress resilience, capitalize on eustress, and lead a happy and productive life.
Instead of producing stress resilience, overdosed exposure to stress in childhood may disrupt the process of learning in the problem valuation network. As a result, we handicap the system which is primed for learned optimism, and designed to produce stoic minds. Instead of stress resilience, we get the opposite. A mind unable to effectively evaluate threats. A mind prone to anxiety disorders.