Positivity effect in aging: evidence for the primacy of positive responses to emotional ambiguity

Older compared to younger adults show greater amygdala activity to positive emotions, and are more likely to interpret emotionally ambiguous stimuli (e.g., surprised faces) as positive. While some evidence suggests this positivity effect results from a top-down, effortful mechanism, others suggest it may emerge as the default or initial response. The amygdala is a key node in rapid, bottom-up processing and patterns of amygdala activity over time (e.g., habituation) can shed light on the mechanisms underlying the positivity effect. Younger and older adults passively viewed neutral and surprised faces in an MRI. Only in older adults, amygdala habituation was associated with the tendency to interpret surprised faces as positive or negative (valence bias), where a more positive bias was associated with greater habituation. Interestingly, although a positive bias in younger adults was associated with slower responses, consistent with an initial negativity hypothesis in younger adults, older adults showed faster categorizations of positivity. Together, we propose that there may be a switch to a primacy of positivity in aging. (c) 2021 Elsevier Inc. All rights reserved.

Automated summary

Older adults exhibit greater amygdala activity towards positive emotions compared to younger adults, and tend to interpret emotionally ambiguous stimuli as positive. Amygdala habituation in older adults is associated with the tendency to interpret surprised faces as positive or negative, with a more positive bias linked to greater habituation. Interestingly, older adults show faster categorizations of positivity compared to younger adults, suggesting a shift towards a primacy of positivity with aging.