Age Is Factor in Optimal Brain Performance

Previously, studies suggest that the attention-based ability to regulate distraction varies across the day coinciding with a circadian-based rhythm that changes as we age. John Anderson, from the University of Toronto (Canada), and colleagues enrolled 16 younger adults (aged 19 – 30) and 16 older adults (aged 60-82) to participate in a series of memory tests during the afternoon from 1 – 5 p.m. During the testing, participants' brains were scanned with fMRI which allows researchers to detect which areas of the brain are activated. Older adults were found to be 10% more likely to pay attention to the distracting information than younger adults who were able to successfully focus and block this information. The fMRI data confirmed that older adults showed substantially less engagement of the attentional control areas of the brain compared to younger adults. Indeed, older adults tested in the afternoon were "idling" – showing activations in the default mode (a set of regions that come online primarily when a person is resting or thinking about nothing in particular) indicating that perhaps they were having great difficulty focusing. When a person is fully engaged with focusing, resting state activations are suppressed. When 18 older adults were morning tested (8:30 a.m. – 10:30 a.m.) they performed noticeably better, according to two separate behavioral measures of inhibitory control. They attended to fewer distracting items than their peers tested at off-peak times of day, closing the age difference gap in performance with younger adults. Observing that: “older adults tested in the morning activated similar cognitive control regions to those activated by young adults (rostral prefrontal and superior parietal cortex), whereas older adults tested in the afternoon were reliably different,” the study authors observe that: “the degree to which participants were able to activate the control regions listed above correlated with the ability to suppress distracting information.”