SSS 2011-04-18（在线收听）

This is Scientific American's 60-Second Science. I'm Cynthia Grabera. This will just take a minute.

Keeping the brain active and engaged appears to combat the cognitive decline associated with getting older. Now a study has found a new, but related, factor in maintaining a sharp mind—the space in which we live.

Researchers recruited almost 1300 senior citizens, none of whom showed any signs of clinical dementia at the start of the study. The participants had their cognitive function tested annually for up to eight years. And they also described their living space. For example, maybe they mostly hung around their bedroom. Perhaps they spent time in the yard. Or frequently traveled.

By the end of the study, 180 people had Alzheimers. And those whose life-space narrowed in on their immediate home were almost twice as likely to develop the condition as those who ventured out. The homebound folks also had an increased risk of other cognitive impairments and a faster rate of cognitive decline. The research was published in the American Journal of Geriatric Psychiatry.

The study's lead investigator, Bryan James of the Rush University Medical Center in Chicago, suggests that, "Perhaps life space is an indicator of how much we are actively engaging and challenging our cognitive abilities."

"Don't fence me in. Let me ride through the wide open country that I love. Don't fence me in."

Thanks for the minute. For Scientific American's 60-Second Science, I'm Cynthia Graber.