Narrator:        This is Science Today. How does a brain actually age? This is a fundamental question that Dr. Adam Gazzaley, director of the Neurosciences Imaging Center at the University of California, San Francisco, is hoping to answer.

Gazzeley:        We know that aging doesn't just affect memory or attention or language or visual-spatial abilities, it affects all of them to some degree, and broadly. So the relevant question seemed to be: What is the sort of base of the pyramid that's influencing all of those abilities? That's what my research really centers around: to understand those basic fundamental changes, in the role of looking for a unifying principle of what occurs.

Narrator:     Gazzeley found there's an interface between how well you remember things that are relevant and how effectively you ignore or filter information that is irrelevant.

Gazzeley:       Older adults, compared to the younger adults, seem to have a preserved ability to focus on the things that are relevant, but an inability as a population to suppress the information that we tell them is irrelevant. And there's a direct correlation between how well they ignore the irrelevant information and how well they remember what they should.

Narrator:        For Science Today, I'm Larissa Branin.