It’s never nice to feel emotionally stressed, but a little stress here and there can help your short-term memory long-term.
New research by neuroscientists at the University of Georgia (UGA) involving more than 1,200 healthy young adults suggests that mental stress is only harmful when it exceeds a certain threshold.
It appears to have a beneficial effect on a person’s working memory at relatively low to moderate levels.
In the study, participants performed a memory test based on the recognition of certain tools and faces. All the while, their brains were being scanned.
By looking back at brain activity during the task, the researchers observed that those participants who reported higher levels of stress on a questionnaire showed less activity in the area of their brain responsible for short-term memories, also known as in working memory.
Meanwhile, those who only experienced low to moderate levels of stress showed elevated working memory activation in the brain. Furthermore, this activity coincided with better performance on the memory test.
The results don’t directly test stress levels or whether stress affects working memory, but they do provide preliminary evidence to suggest a link is at play.
The idea that stress can have a positive or negative effect on human cognition, depending on its severity, stems from the hormesis hypothesis, a theory that emerged from toxicology. Although the validity of hormesis has been challenged in other fields, it is pushing a new frontier of psychological research.
In 2006, a study of just 20 healthy adults found that psychosocial stress can affect working memory, but only when stress levels are relatively high. If they are lower, no effect is seen.
The results suggest that environmental stress isn’t always harmful to how our brains work, but does that mean it’s helpful?
At low enough doses, some researchers suspect it might be.
So far, only a few studies have taken up the hormesis hypothesis and never directly, but the initial results are interesting to consider.
Studies like the current one suggest that preconditioning facilitates an animal’s stress tolerance. In other words, experiencing stress could help a person cope better with stress later on.
In fact, stress management might allow animals to better anticipate future problems and react accordingly.
When adult rats are subjected to chronic mild stress, for example, some studies show that they have improved working memory.
Even in our species, some studies show that low to moderate stress levels are associated with memory benefits.
“Based on this hypothesis, preconditioning is the basis of an inoculation phase in which the organism is instructed to reorganize, prepare and cope with subsequent stress more effectively,” write Assaf Oshri, a psychology researcher at UGA, and colleagues.
But if an individual’s mental or emotional pressure grows beyond what they have learned to cope with or persists over time, the stress can be harmful. It can contribute to muscle tension, high blood pressure, heart disease, immune system problems, bowel disorders, poor working memory, and more.
Interestingly, in the current study, participants who reported having a stronger social support network appeared to have better control over their stress levels.
Therefore, family and friends could be a protective buffer against growing feelings of pressure and tension.
“The findings evidenced in the present study demonstrate the cognitive benefits of exposure to low-moderate levels of stress,” the authors conclude.
“We hope that future longitudinal studies can deepen our understanding of how hormesis may underlie the development of stress adaptation and potentially resilience among people living in stressful environments.”
The study was published in Neuropsychologia.