New research out of Canada asserts older adults really do appear to function better earlier in the day -- a hugely important factor to consider when studying the cognitive abilities of seniors.

Published in the journal Psychology and Aging, the findings showed when older adults were tested in the morning, what clearly proved to be an optimal period, not only did subjects generally perform better on demanding cognitive tasks, but also showed greater activity levels in the same brain networks responsible for paying attention and suppressing distractions, as in younger adults.

Bottom line, the study provided researchers with some of the most compelling evidence yet that there are considerable differences in brain function across the day for older adults.

"Time of day really does matter when testing older adults. This age group is more focused and better able to ignore distraction in the morning than in the afternoon," lead author John Anderson, a doctoral candidate with the Rotman Research Institute at Baycrest Health Sciences and the University of Toronto's Department of Psychology, said in a research institute news release. "Their improved cognitive performance in the morning correlated with greater activation of the brain's attentional control regions ... similar to that of younger adults."

As a result of his team's findings, Anderson recommended older adults schedule their most mentally-challenging tasks -- such as doing taxes, taking a test, seeing a doctor about a new condition or cooking an unfamiliar recipe -- for the morning hours.

For the study, 16 younger adults, aged 19-30, and 16 older adults, aged 60-82, participated in a series of memory tests during the afternoon, from 1 to 5 p.m.

The afternoon testing involved studying and recalling a series of picture and word combinations flashed on a computer screen, with irrelevant words linked to certain pictures and irrelevant pictures linked to certain words flashed on the screen as a distraction.

During the testing, participants' brains were scanned with functional magnetic resonance imaging, which allows researchers to detect areas of the brain are activated.

Older adults during the afternoon sessions were 10 percent more likely to pay attention to the distracting information than younger adults, who were able to successfully focus and block out the superfluous information.

The imaging data confirmed the older adults showed far less engagement of the relevant control areas of the brain, compared to the brains of the younger adults.

In other words, the older adults tested in the afternoon very much seemed to be, as Anderson put it, "idling," functioning in somewhat of a mental default mode, a set of brain regions activated mainly when a person is resting or thinking about nothing in particular.

In contrast, when 18 older adults were tested in the morning, between 8:30 and 10:30, they performed markedly better, according to two separate behavioral assessments.

The morning test-takers paid attention to fewer distracting items than their afternoon peers, managing to close the age difference gap in performance with younger adults.

Importantly, older adults tested in the morning activated the same brain areas young adults did to successfully ignore the distracting information.

"Our research is consistent with previous science reports showing that at a time of day that matches circadian arousal patterns, older adults are able to resist distraction," said Lynn Hasher, senior author of the paper and a leading authority in attention and inhibitory functioning in younger and older adults.

The Baycrest findings, said Hasher, senior scientist at Baycrest's Rotman Research Institute and Professor of Psychology at University of Toronto, offer a cautionary flag to those who study cognitive function in older adults. "Since older adults tend to be morning-type people, ignoring time of day when testing them on some tasks may create an inaccurate picture of age differences in brain function," said Dr. Hasher.