Aging isn't just aching joints and deteriorating organs. It takes a toll on the brain, too, causing people to lose focus and forget. But scientists are offering a new secret for improving brain function in old age: Do your thinking in the morning.

Maybe it's intuitive that old folks are more likely morning people than 20-somethings. Now science proves it. In a study released last month, doctors tested two groups of people — a young group and an old group — for memory and concentration. The ones aged 60 to 82 performed much better between 8:30 a.m. and 10:30 a.m. The findings appeared in the journal Psychology and Aging.

"Time of day really does matter when testing older adults," says lead author John Anderson, a doctoral candidate at the University of Toronto, in a news release. "This age group is more focused and better able to ignore distraction in the morning than in the afternoon." He says the results lead to important recommendations for anybody feeling old age creeping into their brains. It may be better to perform complicated tasks — like doing taxes or taking a drivers license test — in the morning.

The brain changes in a lot of unwelcome ways when we get older, not least of which in its size. The brain actually shrinks, burning off gray matter at a rate of up to 1 percent a year as neurons and synapses disappear, according to a 2010 University of Oslo analysis. Thinking speed slows down. Decisions become more difficult. Memory recall is impaired. All these things happen in healthy brains, to say nothing of dementia.

These brain changes were apparent in the present study, particularly when the subjects were tested in the afternoon using a kind of flashcard memory exam. Participants were asked to remember certain images and words but ignore others. The older participants were more likely to pay attention to these distractions, according to fMRI scans of their brains. But when they took similar tests in the morning, their brains behaved much more like their younger counterparts.

"Their improved cognitive performance in the morning correlated with greater activation of the brain's attentional control regions — the rostral prefrontal and superior parietal cortex — similar to that of younger adults," Anderson said. In the afternoon, on the other hand, the seniors' brains appeared to be "idling"; they looked the way a brain looks when it's thinking about nothing in particular. Anderson says this research will also be useful for other scientists, who should consider time of day as a factor in cognitive studies.

Source: J.A.E. Anderson, et al. Timing Is Everything: Age Differences in the Cognitive Control Network Are Modulated by Time of Day. Psychology and Aging. 2014.