Age-related positivity effect of emotional attention: time and frequency domain

Compared with their younger counterparts, older adults are inclined to allocate more attentional resources to positive over negative materials. This age-related positivity effect has been reported in various experimental paradigms; however, studies have not investigated the attention stage at which it appears or its potential neural mechanism. Thus, we investigated the time and frequency domain dynamics of younger and older adults during emotional attention processes. We obtained electroencephalography oscillation and event-related potential data for 20 older and 20 younger participants while they performed an emotional dot-probe task. We focused our time and frequency domain dynamics analyses on the posterior regions as a key structure for facial emotion perception and the frontal regions as a crucial structure for cognitive control. In the time domain, older adults showed an initial attentional shift to happy-related stimuli, whereas their younger counterparts did not demonstrate emotional modulation, as reflected by the N2pc component. The time-frequency decomposition was analyzed for the N2pc time window. The results showed that compared with younger adults, older adults showed an increased alpha power for happy faces in the right-posterior regions. Moreover, a parallel pattern was seen in frontal theta activity. The current findings highlight how electrocortical activity of the brain might moderate the tendency to prioritize positive information among healthy older adults. The emergence of an age-related positivity effect may be related to frontal cognitive control processing. These findings provide insight into the prevention and treatment of unsuccessful aging, such as late-life depression and anxiety.