Abstract: Age-related positivity effect refers to the phenomenon that older adults display a preference for positive rather than negative information in cognitive processing. Recent researches in working memory (WM) have found the effect of the interaction between emotional valance and task-relevance on positivity effect. Positivity effect has been observed in WM studies with emotional valence acting as a kind of task-relevant information. For instance, older people have enhanced performance in WM tasks with positive emotional stimuli, and decreased performance on negative emotional stimuli. In contrast, less attention has focused on the area of emotional valence as task-irrelevant information in WM and conflicting findings also have been reported. These remind that both emotional valence and task relevance are critical components in the processing of positivity effect in WM. Preliminary neuroimaging studies have revealed that the associations between age-related functional changes in the dorsal executive system and ventral affective system and the age effect in emotional process of WM. The socioemotional selectivity theory and the dual-competition model have been found to mainly account for age-related positivity effect in WM. But there is a lack of empirical evidence to support the dynamic integration theory. Overall, future studies are warranted in exploring the characteristics of emotional processing in different stages of WM in older adults, clarifying the potential influences of internal encoding processes of emotional materials on the mechanism of positivity effect, uncovering the important neural circuits related to the impact of task-relevance of emotion on positivity effect, as well as revealing the underlying mechanisms and potential benefits of emotional WM training on the improvement of cognitive functions and emotional experience in the elderly.

Key words: working memory, positivity effect, task-relevant, task-irrelevant, emotional valence