Canadian researchers studied brain rhythms in a small number of subjects and observed that optimal functioning occurs increasingly in the morning as we age.
The findings provide strong evidence that aging adults should perform their most demanding tasks in the morning.
"Time of day really does matter when testing older adults," says lead author John Anderson, a PhD candidate with the Rotman Research Institute at Baycrest Health Sciences and University of Toronto, Department of Psychology. "This age group is more focused and better able to ignore distraction in the morning than in the afternoon."
The study involved 16 younger adults between the ages of 19 and 30 and 16 older adults from age 60 to 82.
Researchers imposed successive memory tests between the hours of 1 p.m. and 5 p.m. that required participants to observe and recall pictures and word combinations after observing them on a computer.
The tests employed techniques to distract participants and participants' brains were scanned using fMRI to pinpoint which areas of the brain were activated at a given time during testing.
Results showed that the older group was 10 percent more likely to succumb to distractions than their younger counterparts.
A group of 18 older participants in the aforementioned age group were tested between the hours of 8:30 a.m. and 10:30 a.m. and performed significantly better, that is to say equally well as the younger group.
Results of the fMRI scans show that the older adults activated the same brain lobes as the younger set to block distractions, whereas researchers noted discrepancies between the age groups during afternoon testing.
"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," says senior author Dr. Lynn Hasher, a leading authority in attention and inhibitory functioning in younger and older adults.
The study was published in the journal Psychology and Aging.