Multitasking 'Switch' Doesn't Work As Well In Older Brains

Using magnetic resonance imaging to track blood flow, researchers asked two groups — one whose average age was 24 and another whose ages averaged 69 — to briefly view a nature scene. When a face suddenly popped up, the subjects were asked to determine the age and gender of the face, and then asked to recall the original nature scene.

The brain scans showed that the memory-encoding networks of the younger group fired up again right after the unexpected distraction, quickly refocusing on the nature scene. The brains of the older adults proved more rigid, failing to disengage from the interruption and reestablish the neural connections needed to switch back to focusing on the original memory.

"This study provides the first understanding of the neural brain mechanisms responsible for multitasking and memory in older adults," says the study's senior author, Adam Gazzaley, M.D., director of the UCSF Neuroscience Imaging Center. The research also shows that working memory is very fragile, he says. "Over the course of seconds, one interruption erases memory quality."

The research provides a "biological window" into some of the "inefficiencies" of the aging brain, says Ronald C. Petersen, M.D., neurologist and director of the Mayo Clinic Alzheimer's Disease Research Center.

Work is already under way in Gazzaley's lab to develop brain-training software that might help older adults better cope with interruptions.

Loren Stein is a freelance writer who lives in Washington, D.C.

• Focus: If you want to increase your chances of remembering something, stay focused on it. Don't allow yourself to be interrupted when you're studying important information or doing something you'll want to remember later, such as hiding a key or creating a new secret password.
  
  
• Cut distractions: When high quality and performance are demanded, in the workplace or at home, cut out distractions: Shut the door, turn off your cellphone and quit your email program.
  
  
• Brain train: Keep your brain as active as possible to preserve its plasticity. Learn a new language. Cultivate new hobbies. Exercise. Challenge yourself and stay engaged.