Scientists know that our brains shrink with aging, but does less gray matter really matter?

Apparently not, according to a new study of 446 people in Australia.

"We found that, on average, men aged 64 years have smaller brains than men aged 60," said Helen Christensen of the Australian National University. "However, despite this shrinkage, cognitive functions -- like memory, attention and speed of processing -- are unaffected."

The conclusion was based on questionnaires and brain scans.

The study, announced Friday, yielded another surprise. Previous studies had indicated that higher levels of education or continuing intellectual activity could serve as a sort of Pilates for the brain, keeping an aging mind fit.

"Our findings do not support these beliefs," Christensen said. "In the present study, we found no relationship between brain shrinkage and education level."

Older minds do sometimes fail, of course, owing to conditions such as Alzheimer's that scientists are only beginning to understand. Little is known about brain shrinkage, too.

"It is known that the brain shrinks over the course of a person's life, although the exact trajectory is not well understood, and there are huge individual differences," Christensen said.

Related Stories

Chronic Pain Shrinks People's BrainsMen and Women Really Do Think DifferentlyHang in There: The 25-Year Wait for ImmortalityStudy: Your Brain Works Like the InternetWinter Shrinks Mice Brains