At The Right Levels, Stress Can Have a Surprising Impact on Memory : ScienceAlert


It’s never nice to feel emotionally tense, but a little stress here and there might actually help your short-term memory in the long run.

New research from neuroscientists at the University of Georgia (UGA) involving more than 1,200 healthy young adults suggests mental stress is only detrimental when it crosses a certain threshold.

It appears to have a beneficial effect on a person’s working memory at relatively low and moderate levels.

In the study, participants performed a memory test based on recognizing certain tools and faces. All the while, their brains were being scanned.

When looking back at the brain activity during the task, researchers noticed those participants who reported higher levels of stress on a questionnaire showed less activity in the area of their brains responsible for short-term memories, also known as working memory.

Meanwhile, those who experienced only low to moderate levels of stress showed elevated working memory activation in their brains. What’s more, this activity coincided with better performance on the memory test.

The results do not directly test stress levels or whether stress impacts working memory, but they do provide preliminary evidence to suggest a link is at play.

The idea that stress can exert a positive and negative effect on human cognition, depending on its severity, stems from the hormesis hypothesis, a theory borne out of toxicology. While the validity of hormesis has been contested in other fields, it’s pushing a new frontier of psychological research.

In 2006, a study among just 20 healthy adults found that psychosocial stress can impair working memory, but only when levels of stress are relatively high. If they are lower, then no effect is seen.

The findings suggest environmental stress isn’t always harmful to the functioning of our brains 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 on 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 an individual better cope with stress later.

In fact, managing stress could allow animals to better anticipate future problems and react accordingly.

When adult rats are put under chronic mild stress, for instance, some studies show they have improved working memory.

Even in our species, some studies show low to moderate stress levels are associated with memory benefits.

“Based on this hypothesis, preconditioning underlies an inoculation phase in which the organism is cued to reorganize, prepare, and behaviorally cope with subsequent stress more effectively,” Assaf Oshri, a psychology researcher a UGA, and colleagues write.

But if an individual’s mental or emotional pressure grows beyond what they have learned to cope with or persists over time, stress can prove detrimental. It can contribute to muscle tension, high blood pressure, heart disease, immune system issues, bowel disorders, poorer working memory, and much more.

Interestingly, in the current study, those participants who reported having a stronger social support network seemed to have a better handle on their stress levels.

Family and friends could therefore be a protective buffer against increasing feelings of pressure and tension.

“Findings evidenced in the present study demonstrate the cognitive benefits of exposure to low-moderate stress levels,” the authors conclude.

“We hope that future longitudinal studies can further our understanding of how hormesis may underlie the development of adaptation to stress and potentially resilience among individuals living in stressful environments.”

The study was published in Neuropsychologia.


Source: Science Alert

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