Stress boosts brainpower. It enhances memory and makes people more alert. Accumulating research confirms the beneficial effects stemming from confronting stressful circumstances. It seems that dealing with stress makes the human brain stronger. By contrast, cognitive sharpness wanes in those whose lives are comparatively stress-free.
"Predictable chronic mild stress (PCMS)... is beneficial to the adult brain... (and) leads to enhanced memory," write researchers V.K. Panbar, B. Hattiangudy and their colleagues. "(Stress) increases hippocampal neurogenesis and improves mood and cognitive function."
In a recent report, Daniela Kaufer at the University of California concludes that stress "has a clear beneficial effect."
Researchers admit the precise cognitive mechanism by which stressful challenges can enhance brain functions is unclear, but some fundamentals have emerged.
According to researchers at Rockefeller University, dealing successfully with troubling stressful situations "makes you smarter."
Among the positive consequences are a vastly improved working memory and enhanced "production of neurotransmitters in the prefrontal cortex."
These benefits accrue as a result of "routine stress exposure in day-to-day life (which) decrease depressive- and anxiety-like behaviour for prolonged periods," the Panbar team reported. "(There is) about a 1.8-fold increase in the production and growth of new neurons in the hippocamus."
Neurologists have concluded that stress generates a protective shield of responses that go far beyond merely dealing with the source of the stress itself.
"We stress to perform better," explains Zhen Yan at the University of Buffalo. "Stress hormones have protective effects on the body (and) acute stress can have a beneficial effect on learning and memory through the stress hormone cortisol."
People whose lives are stressful make fewer cognitive errors in comparison with those whose lives are less stressful the researchers have pointed out.
In addition, stressful challenges do not generally increase depression nor anxiety, the researchers report.
"(There is a positive) impact of acute stress on working memory, a cognitive process depending on glutamate receptors mediating signals in the prefrontal cortex circuits," Yan explains.
Stress not only enhances memories related to the sources of stress, but the effect also applies to unrelated memories, expanding the beneficial impacts beyond what scientists had anticipated.
"Stress can activate memory, even if the memories are unrelated to the stressful experience," reports Andre Fenton at New York University.
Research colleagues Karel Jezek at the (Czech Republic) Academy of Sciences, Benjamin Lee at SUNY Downstate and Katherine McCarthy at Rockefeller University have demonstrated that stress can even reactivate long-dormant unrelated memories, as if reawakening them from the deep recesses of the brain where they had been locked.
Researchers suggest that as the human species developed, successful overcoming of stressful challenges flowed from increased memory-enhancing cognitive activity correlated with recollecting successful strategies for dealing with similar previous stress-generating situations. The stress-memory interrelationship has proven to be so successful that it has proven to be an enduring survival tool.
Robert Alison is a zoologist and freelance writer based in Victoria, B.C.
See also: 'Toxic stress' is hurting our children, Nicole Letourneau and Justin Joschko conclude at wfp.to/comment.