The effect of stress on mice... and (wo)men

Wise companies long ago realized that providing stress-busting “perks” — e.g., health insurance, childcare, quality lunches, gym memberships, ample vacation time, psychological counseling, flex time, workplaces with natural lighting, convenient transportation (like the Google bus for Google employees) — is not just a nice thing to do for employees but a huge productivity booster.

Scientists are now uncovering hard proof:

[C]hronically stressed rats lost their elastic rat cunning and instead fell back on familiar routines and rote responses, like compulsively pressing a bar for food pellets they had no intention of eating.

Moreover, the rats’ behavioral perturbations were reflected by a pair of complementary changes in their underlying neural circuitry. On the one hand, regions of the brain associated with executive decision-making and goal-directed behaviors had shriveled, while, conversely, brain sectors linked to habit formation had bloomed.

In other words, the rodents were now cognitively predisposed to keep doing the same things over and over, to run laps in the same dead-ended rat race rather than seek a pipeline to greener sewers. “Behaviors become habitual faster in stressed animals than in the controls, and worse, the stressed animals can’t shift back to goal-directed behaviors when that would be the better approach,” Dr. Sousa said. “I call this a vicious circle.”

Robert Sapolsky, a neurobiologist who studies stress at Stanford University School of Medicine, said, “This is a great model for understanding why we end up in a rut, and then dig ourselves deeper and deeper into that rut.”

Posted by James on Tuesday, August 18, 2009