Researchers who test cognitive performance may want to take heed of a recent study that suggests older adults who are tested in the morning - their optimal time of day - perform better on cognitive tasks.
The researchers, from the Rotman Research Institute at Baycrest Health Sciences and the University of Toronto in Canada, publish their results in the journal Psychology and Aging.
"Time of day really does matter when testing older adults," says lead author John Anderson. "This age group is more focused and better able to ignore distraction in the morning than in the afternoon."
He and his colleagues note that their study provides the strongest evidence yet that there are measurable differences throughout the day in brain function for older adults.
To conduct their research, the team observed 16 younger adults between the ages of 19-30 and 16 older adults between the ages of 60-82 as they took part in a sequence of memory tests between 1:00 and 5:00 pm.
For these tests, the participants needed to study and recall a set of picture and word combinations that appeared on a computer screen. As a means of distraction, the researchers programmed irrelevant words linked to certain pictures and irrelevant pictures linked to certain words to appear on the screen.
While the participants were completing the testing, the researchers scanned their brains with functional magnetic resonance imaging (fMRI), which allowed them to observe which areas of the brain were activated.
Older adults tested in morning activated same brain areas as younger group
The researchers found that the older adults were 10% more likely to focus on the distracting information than the younger adults, who largely blocked out this information successfully.
Additionally, the data gleaned from the fMRI scans showed that the older adults showed significantly less activity in the attentional control areas of the brain in the afternoon, compared with the younger adults.
The older adults who were tested in the afternoon showed signs of "idling," the researchers say, which means they were showing activations in the default mode - a set of regions that are activated when a person is resting or thinking about nothing in general.
This could indicate that the adults were having a hard time focusing, because when a person is fully aiming their attention at something, resting state activations are suppressed.
But there is a silver lining for older adults. The team found that when another group of 18 older adults was tested in the morning between 8:30 and 10:30 am, they performed significantly better.
In detail, they focused on fewer distracting items than their peers who were tested in the afternoon, and they even closed the age difference gap in performance with the younger adults.
When the older adults were tested in the morning, the researchers observed that they activated the same brain areas as the young adults did to ignore the distractions. And this could suggest that time of day when older adults are tested is an important factor in how well they perform and what kind of brain activity researchers can expect from them.
Commenting on the findings in the older adult group, Anderson explains:
"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 young adults."
Older adults should schedule mentally taxing activities for morning
Dr. Lynn Hasher, senior author on the paper, says their 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."
She adds that ignoring time of day when testing older adults on certain tasks "may create an inaccurate picture of age differences in brain function."
In light of their findings, Anderson recommends that older adults schedule their most mentally difficult tasks - such as doing taxes, taking a test, seeing a doctor about a new condition or cooking a new recipe - in the morning.
Medical News Today recently reported on a study that suggested people who can quickly process visual information in later life are more likely to stay mentally acute as they age.