You can actually use Stress to Improve Memory and Learning

Highlights

• Temporary stress improves attention, makes us efficient, improves memory for relevant details, and makes us “faster” – in short, better learners.
• Moderate stress before learning new facts and concepts enhances memory, but stress before tests, performances, and knowledge updating impairs memory.
• Just enough stress to feel challenged is generally good for learning.
• A sweet spot of stress optimizes learning. This stress can come from the tasks or the environment.
• Information acquired in a stressful state improves recall in similar contexts.
• Stress rarely affects procedural memory (sequences) and emotional memory, but worsens declarative memory (facts) and neutral memory.
• Stress shifts learning from a deliberate deep thinking process to a shallow automatic process, but this automatic process compensates for the lack of thinking to keep performance stable. Stress helps rote learning, but not deep understanding.

How stress affects the brain and body

Stress occurs when we don’t have the capacity to deal with a circumstance. According to the pioneering endocrinologist Hans Selye, it is a “nonspecific response of the body to any demand.^[1]” Momentary stress isn’t bad because it helps us adapt and overcome obstacles. However, chronic stress is a problem and should be kept under control because it accelerates aging^[2], weakens the immune system^[3], lowers productivity^[4], and hampers relationships^[5]. Since memory and learning are two of the brain’s core functions, stress affects both. Moderate stress motivates us to adapt and increase goal-directed behavior, so instead of relaxing, we can use it to improve learning. But if stress is too high, our motivation to consume information, called appetitive behavior, reduces and becomes aversive behavior^[6], meaning we are more likely to avoid learning and performance.

The adrenal gland above the kidneys release the hormone cortisol as a response to stress. Stress triggers^[7] dopamine, adrenaline, and noradrenaline, which increase glucose supply and also instantly activate physical and psychological responses to get the brain to adapt and cope. Cortisol’s effects last hours to weeks, and too much of it becomes toxic causing neuron cell death. This cell death is likely to impair declarative memory (facts, events, knowledge).

Stress increases the body and brain’s readiness to pay attention and temporarily improves response speed without lowering accuracy^[8], processing efficiency^[9], memory for relevant information, and focused attention^[10]. This cognitive change naturally improves memory and learning. But too much stress has long-term cognitive problems like damaging memory structures^[11] in the brain’s memory area called the hippocampus.

Learning and memory are 2 related concepts. Learning is the process of acquiring memory, and stored memory is used to learn more. Here, we’ll focus on learning and memory based on declarative memory (facts, concepts, events, details) and procedural memory (methods, skills, habits, routines, rote learning).

Mild stress improves focus and memory for relevant details, and makes us efficient and "faster" – in short, better learners. But chronic stress leads to low productivity, memory loss, relationship trouble, and low immunity. Share on X

Some learning processes improve with stress, while others worsen

While learning, memory undergoes 4 processes:

• Encoding (taking the information).
• Consolidation (converting it to long-term memory during idle time and sleep).
• Retrieval (remembering the information during a test or performance).
• Updating (memory gets new information during revision or new learning).

Stress uniquely affects each of these processes. Generally^[12], stress just before encoding and consolidation improves memory. But stress before retrieval and updating impairs memory. Having stress long before encoding starts also impairs memory.

Suppose you are learning new facts for the first time. Stress before it can improve your memory for facts. Learning is consolidated in the brain during rest, and stress before rest can help too. So ideally, if you are stressed after acquiring new information, it might work in your favor if you rest after it. A possible reason for this is stress arouses the brain to use more resources to store information. Stress is bad if you are taking a test or getting ready to perform a skill. And it’s also fairly disruptive when you are updating your knowledge.

To use stress strategically for better learning, focus on learning new facts and concepts right after a short stressful period, and then test yourself and learn more after you’ve relaxed and slept the next day.

There is a good type of stress called “eustress” that arouses you just enough

Hans Seyle, the most notable stress researcher, gave us a popular concept in the 1970s – the concept of good stress called eustress. Eustress, according to him, is the opposite of stress (eu is Latin for ‘good’). Eustress is positive stress that benefits learning/performance, while stress is a negative burden that hampers learning/performance. Bad stress and Eustress are both just stress^[13], but the difference is in the effects of that stress and sometimes in the cause.

The Yerkes-Dodson curve^[14] suggests that an optimal stress level leads to optimal memory and learning performance. If it is too low or too high, performance worsens. Similarly, there is an optimal level of arousal where just enough arousal helps us focus or learn^[15]. In some cases, there is simultaneous stress from the environment while learning, or it is in the very nature of the learning or performance. This stress is called cognitive load, and evidence suggests a moderate amount^[16] of cognitive load is good for learning.

Some level of stress^[17] also increases motivation. Stress from challenges tends to improve learning and motivation to learn, while stress from hurdles and inconveniences worsens learning and the motivation to learn. What this means for everyday, professional, and academic learning is that a slight level of difficulty is good for learning, but stress from noise, a bad environment, improper tools, poor learning resources, etc., is bad for learning.

Even in a job-learning scenario^[18], stress from hindrances can reduce innovative performance when an employee isn’t very motivated to learn on the job or isn’t clear about what/how to learn the necessary skills. Having too much autonomy is related to low innovation when there are hindrances. The explanation here is that limited resources and some structure at work help innovation and creativity in general.

Slight stress, like feeling challenged, can put you in the flow state. Feeling challenged is necessary to enter the flow zone, along with being motivated and feeling one with the task. So while learning, if the information is just difficult enough to not stress you out but keep you challenged and engaged, you may get engrossed in it. That minor gap between your current knowledge and new knowledge promotes curiosity; if there is no gap or too much gap, it creates boredom.

Essentially, research points to the idea that a person will learn and perform best when there is optimum stress. This is eustress. What counts as optimum varies between people and tasks, so you may want to test it yourself.

Stress can improve memory depending on the context and emotions

A lot of learning is in contexts and emotions. Some research says^[19] that when a stressful context matches the content of memory, our memory for it enhances. What we learn in a stressful period might be more accessible in a similar stressful moment. So learning traffic rules while watching stressful road accident videos can potentially improve your memory for traffic rules. Similarly, learning first aid in a stressful situation might help you remember the details in a situation where you need first aid. Generally, when stress hormones participate in learning and guide neurons related to that specific context and the same context appears again, we demonstrate better memory^[20]. Stress may even tag memory with “high importance” making it easy to remember.

Stress enhances emotional memories^[21] when stress occurs just after remembering emotional details. It helps to consolidate memories (convert them to long-term memory) through extra resources supplied by the stress hormones. For example, you may remember the details of a stressful conversation about a past event because stress helped to consolidate the memory. You could effectively attach emotional significance to what you learn and remember the details just before another anxious moment to improve that learning.

Another study found^[22] stress can enhance memory for emotional events too, but it interferes with a memory process called “reconsolidation.” When we form a memory, we consolidate it – send it to long-term memory. When we remember that memory, it enters an unstable state prone to changes that need to restabilize through “reconsolidation.” Stress disrupts reconsolidation weakening the memory, but doesn’t affect emotional autobiographical memories. So you may forget trivial details about your life but remember the emotionally powerful ones. Like your first date, the day you got a promotion, the day your performance evaluation was negative, and the day you bought something you loved very dearly.

After learning something for the first time, especially emotionally relevant learning, stress improves the transfer to long-term memory (consolidation). On the contrary, experiencing stress after remembering personal experiences and thinking about them again (reconsolidation) makes the memory fragile and prone to decay. So you may strategically use stress after learning to improve long-term memory, but avoid stress after remembering it. And if you fail to remember anyway, it may be easier to recall in a similar scenario.

Stress makes rote and procedural learning easy, but not deep understanding

In one study^[23], researchers gave cortisol to healthy people and tested their declarative memory, procedural memory, and spatial thinking (location-based reasoning). Their test results showed that cortisol impaired declarative memory and spatial thinking, but not procedural memory. One possibility is that procedural memory is like a habit that we have deeply ingrained through repetition. Elevated cortisol may not impair such rigidly developed memories. For example, stress could hamper recalling facts (declarative memory) and navigating (spatial thinking) on the road, but it probably won’t affect the actual ability to drive (procedural memory).

In a way, if procedural memory is very strong, stress might not affect your performance. Improving procedural memory means practicing a routine or method so much that it becomes intuitive. Procedural memory is not just physical, like dribbling a basketball; it can be cognitive, like reciting lyrics or using the “(a+b)2” formula. When stress rises^[24], we tend to shift our learning style from using our declarative memory to using our procedural memory. So our learning resorts to more intuitive understanding and “rote learning” instead of deep processing. Rote learning is remembering without understanding.

In many cases, this shift might not actually hamper the overall learning outcome and performance, but it may only improve learning superficially without much understanding. For example, you may learn how to use software without knowing how it works. You may learn a method without understanding why it works. You may learn what syntax to use without knowing why it makes sense.

Sometimes, procedural learning is enough to ace a test, know the correct answers, and get better at your job. For example, learning an instrument, names of diseases, or a presentation is procedural memory, while learning how an algorithm does what it does is declarative memory. Procedural memory is knowing what tool to use at work and what to expect from it. Learning to cook with ingredients is also procedural memory, and in many walks of life, the useful bit of learning is procedural memory. In fact, expertise is a large set of procedural memories.

In short, to get good at the “How” of learning, improve procedural memory. To get good at the “What” and “Why,” improve declarative memory. When you are stressed, you can purposefully focus on the “how” to do something and not “why” it works because stress shifts your brain’s resources to go rote and procedural. Then, after a while, the learning will become intuitive.

Chronic stress

All forms of stress can’t improve learning and memory. A combination of remembering old experiences and stress tends to make the memory fragile because stress disrupts reconsolidation. The fragile memory can then break and decay with continuous stress, leading to forgetfulness. Similarly, stress and negative thoughts about the past can make memory hazy because those negative thoughts become fragile and the memory changes into a new one, sometimes a more negative one.

Research shows^[25] a strong link between long periods of stress and memory loss in cognitively healthy older adults. However, those with mild cognitive impairment might benefit from a little stress. Why this may happen is unknown, but some stress slows down the expected cognitive decline in those with mild cognitive impairment. One reason is that those who know they have compromised memory could put in more effort, and increased cortisol could enhance attention, which indirectly improves memory.

Temporary stress^[26] can worsen declarative memory, which is our memory for facts, learned information, and personal stories. Performance stress can disrupt declarative memory in a way you forget what you’ve previously learned. Anticipating stress can take your attention away from your task and hamper performance. So, anticipating stress during tests or performance can negatively impact learning for a student or a fresh learner at work. If anticipation causes stress, and there are frequent stressful events, stress may become chronic.

Coping with stress

How you cope with stress can also affect long-term learning. In a study on college students^[27], researchers observed those who used problem-focused coping for stress did better at academics than those who used emotion-focused coping. Problem-focused coping is a problem-solving mindset where effort goes toward overcoming difficulties. Emotion-focused coping is managing the emotional responses to stress via talking, therapy, relaxation, and counseling. Emotion-focused coping can be exhausting, while problem-focused coping typically reduces future stress.

Relaxation techniques or emotional regulation techniques can lower stress before it becomes chronic. Music, exercise, yoga, meditation, and day-to-day hobby routines like ironing, reading, & puzzles, are good ways to counter acute and chronic stress. Chronic stress reduces when you engage in enough holistic restorative activities which restore your attention, reduce muscle fatigue, lower cortisol, and replenish biological resources like nutrients and water. Sleep is the most ideal restorative activity, but it’s often not enough. So you may need to take breaks, eat, do non-work fun activities, and perform relaxation exercises to get additional psychological rest.

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