Dr. Rajita Sinha,a professor of psychiatry and neurobiology at Yale University sorts through the effects of stress on memory, and it’s relationship to dementia….
Stress works on a spectrum, says Dr. Sinha. At on end is controllable stress, where if you take the correct action you can regain control. “Imagine you notice the fridge is almost empty, but if you hurry you can get to the store before a forecast snowstorm hits,” she says. At the other end is uncontrollable stress. Losing your home or ending a significant relationship would fit in this category, she says. The two types often overlap.
The brain grasps an uncontrollable threat very quickly and can retrieve relevant information immediately when presented with the same acute stress again. When you are out alone on a street at night, your stress response might help keep you alert the next time you are alone and feel in danger. “That experience sharpens the mind before the next test,” Dr. Sinha says.
Controllable stresses, too, leave an imprint, such as not having enough time to study for an exam. “Your mind will remember that experience, and you will allow for more time to study before the next test,” she says.
Yet studies looking at multiple simultaneous stresses – either controllable or uncontrollable – show they lead to poor memory retrieval “because the brain’s capacity to think is fractured.”
A person running late for a meeting may forget where he put his car keys, or a homeowner threatened with foreclosure might not recall his own phone number. “What makes us human is to think creatively and emotionally, to allow us to be rational and wise,” she says. “But if you have multiple things going on, that is thrown out the window, and you are emotionally overwhelmed.”
Recent studies have shown the risk for dementia and other memory-related illnesses rises significantly the more people encounter uncontrollable stress. Studies using brain scans show that loss of a significant other or witnessing violence does take a toll. “Research has shown that whole branches of brain cells can shrink and start to disappear,” she says.
The good news is the brain is dynamic, and neuron damage can be reversed. Dr. Sinha says brain research has documented so-called neurogenesis, although science hasn’t pinpointed what sorts of stress-related memory loss can be reversed.
She recommends you avoid multitasking whenever possible. “If you do 10 different things at once, you’re only using one-tenth of your brain for each task, which makes it hard to perform at your peak level,” she says. “That can increase stress levels.” The result: Forgetting where those darn keys are.
March 16, 2015