By Ronnie Cohen
NEW YORK (Reuters Health) - Older adults are better able to ignore distractions and to perform demanding cognitive tasks in the morning, a new study suggests.
Moreover, when tested in the morning, at their peak period of alertness, seniors activated the same brain regions used to focus attention and tune out distractions as 19 to 30 year olds, researchers found.
The findings show “the typical effect of aging is reduced when older adults are tested at the ideal time of day,” psychologist Ulrich Mayr told Reuters Health.
“The brain of an older adult tested in the morning looks more like a young adult,” he said.
Mayr, a professor at the University of Oregon in Eugene, studies aging and executive control but was not involved in the current research.
The new study – a small one – was led by John Anderson, a doctoral candidate in psychology from the University of Toronto’s Rotman Research Institute.
The researchers administered a series of memory tests to younger and older adults in morning and afternoon sessions.
Eighteen adults aged 60 to 87 took the tests between 8:30 and 10:30 in the morning. In the afternoon, between 1:00 and 5:00, another 16 adults in the same age range took the tests, as did 16 younger adults (ages 19 to 30).
The authors explain in the journal Psychology and Aging that participants performed a series of tasks with pictures and words on a computer screen while irrelevant words and pictures flashed before them. At the same time, researchers scanned participants’ brains with magnetic resonance imaging (MRI).
The study found significant differences between older and younger people’s brain scans when older people took the tests in the afternoon, but not when they took the tests in the morning, Anderson told Reuters Health.
In the afternoon, older adults activated the brain regions involved in ignoring distracting information only 5.4 percent as often as young adults, Anderson said. But in the mornings, the older group activated those regions 41.4 percent as often as young adults – still less than half as much but significantly more frequently, he said.
“It’s good news,” Anderson said. “Older adults are more focused and better able to ignore distraction in the morning than in the afternoon.”
“Cognitive decline is not as drastic as people thought it was. If you test people at their off-peak time of day, it’s going to exaggerate that,” he said.
The older adults’ better results in the morning correlated with greater activation of two regions of the brain that control attention – the rostral prefrontal and superior parietal cortex, Anderson said.
Earlier studies have found age and individual differences in alertness patterns, with older adults tending to be better able to stay on task in the morning, the authors write. But the influence of circadian rhythms and time of testing has been largely unexplored with neuro-imaging tools like MRI, they say.
The study findings suggest that older adults might do well to schedule intellectually challenging tasks in the morning, when they are likely to be most alert, Anderson said. In addition, he said, physical therapy and other treatments requiring concentration might be more effective for older people during their optimal performance time.
Dr. Lynn Hasher, the study’s senior author, said in a statement that the results should raise a cautionary flag to researchers studying cognitive function in older adults. Hasher is also from the University of Toronto.
"Since older adults tend to be morning-type people,” she said, “ignoring time of day when testing them on some tasks may create an inaccurate picture of age differences in brain function."
SOURCE: http://bit.ly/1pxhpxA Psychology and Aging, July 7, 2014.