August 31, 2005
The Impact of Stress on Learning and Memory
This is a photograph I recently took during my travels in Maine. Its a very peaceful scene with my nephews paddling on a pond at sunset. As luck would have it, I captured in the foreground the concentric rings of tiny waves created where a fish jumped. You can also see lily pads and grass growing in the water. I wish every day were as beautiful and carefree as depicted in this photo. But they are not. Indeed, our lives are full of stress and I've begun to think about how it impacts our ability to learn and remember.
I think most of us are intrinsically aware that people under stress have a more difficult time learning and remembering things. At one point in our lives all of us has been "stressed out" about something and performance at school or work (or life in general) suffered. Personally, over the past year, I've had increasing difficulty expressing myself clearly and remembering the little things that once came so easily to me. This may be a function of age-related memory loss (I hope not!!) or it may be related to a persistent level of stress or perhaps both. Why does stress impact learning and memory? This may be related to several factors. First, people who are under a lot of stress have a difficult time paying attention to the sensory inputs in the immediate surroundings - their minds are pre-occupied with other thoughts and are not focused on perceiving, interpreting, and reflecting on new information in the environment. Second, stress hormones cause disturbances in our brain chemistry (don't ask me the details ... remember, I'm a primary care practitioner ... not a biochemist!) which appears to make accessing previously learned material more difficult. Just think back to a particularly stressful exam!
Stress is a self-percieved phenomenon. A situation or environment that seems stressful to one person is an unnoticed annoyance (or perhaps even pleasurable) to someone else. A certain amount of stress can be very useful and, when its not excessive, it can enhance performance. People who are "challenged" to meet high expectations often meet them. Thus, "low balling" learners to make things easy or stress-free isn't productive. I think the best analogy for this phenomena is the Starling curve (actually, its called the Frank-Starling curve ... but most of us seem to forget about Otto Frank who was Ernst Starling's partner!). In the Frank-Starling curve, cardiac output improves with increasing preload (left-ventricular end diastolic volume) and is dependent on stroke volume. In other words, if you push more into the heart (e.g. stress it) it will end up pumping out more (if the heart is healthy) ... at least to a point, and then it progressively goes into failure. The point at which the heart will begin to go into failure is variable from one individual to another. Individuals who already have some degree of cardiac dysfunction can accommodate much less pressure before they go into failure. That's why we give them drugs to reduce pre-load. And analogously, people who already have cognitive dysfunctions (e.g. learning disabilities, cognitive impairment due to age or disease, mental illness, or difficulty coping to a new life situation) can be pushed into "learning failure" more easily. As teachers, particularly as college professors who are trying to develop professionals who continue to perform well even under situations where there is significant stress and pressure, how much should we accommodate the needs of these individuals? How much should we reduce the pre-load? Certainly, the learning environment should not be purposely stressful. Further, students should be given encouragement and their confidence boosted (when appropriate) with positive affirmations about their ability to succeed. Any student who has a temporary stressor (i.e. death in family, moving, divorce) should be accommodated for awhile. But how about those who are always "stressed out." Perhaps we should be offering (or even requiring) these students to learn and regularly engage in a variety of stress management techniques? Food for thought.
You can find a wealth of information about the relationship between stress and learning at: http://www.trainingplace.com/source/stress.html
Posted by Stuart T. Haines, Pharm.D.