Age differences in cognitive control of emotional memory: metacognitive aspects and neural correlates
thesisposted on 23.05.2021, 14:42 by Sara Nicole Gallant
Previous research has identified a divergent trajectory for the aging brain, characterized by declines in cognition and preservation in emotional processing. According to the socioemotional selectivity theory, reduced time horizons in later life cause a motivational shift to prioritize emotional goals, such as positive well-being. In service of these goals, older adults devote more cognitive effort to attend to and remember positive information; however, whether they can exert control over such information once it enters memory is not well understood. The primary aim of this dissertation was thus to examine age-related changes in cognitive control of emotional memory including its underlying metacognitive and neural components. In three experiments, young and older adults completed a cue- or value-based version of the item-directed forgetting task for positive, negative, and neutral words. Results consistently demonstrated that young and older adults could strategically control encoding of emotional information, by prioritizing relevant over irrelevant words in memory. This was evident when encoding was directed by to-be-remembered (TBR) or to-be-forgotten (TBF) cues as well as by numeric points that signaled a gain or loss of value (+10 vs. -10). Extending previous research on metacognition and aging, results indicated age invariance in prospective judgments of learning made during the encoding of TBR and TBF words that varied in emotion. In contrast, age groups differed when retrospectively monitoring the source of words. Whereas young adults’ source monitoring was not influenced by emotion or cues, older adults tended to attribute positive items to sources that were higher in value for memory (TBR or +10 cues), consistent with an age-related bias to prioritize positivity. Finally, age differences in event-related potentials underlying encoding of TBR and TBF words provided evidence that older adults may recruit additional resources in frontal regions of the brain to facilitate task performance. Moreover, in line with behavioural results, the ERP signatures of directed forgetting were not modulated by emotion. Altogether, this dissertation demonstrates that cognitive control over emotional memory is intact in later life; however, it highlights important age differences in the metacognitive and neural correlates of this ability.