The influence of task complexity and information value on feedback processing in younger and older adults: No evidence for a positivity bias during feedback-induced learning in older adults

Humans flexibly adapt their behavior using feedback from their environment. This ability is impaired in old age, but recent research suggests this mainly concerns processing of negative feedback and that positive feedback might be spared. The aim of this study was to test this idea of an age-related positivity bias against the possibility of a strategic focus on relevant feedback due to limited processing resources in old age. For this purpose, 17 younger (aged 19 to 28 years) and 18 older (aged 69 to 79 years) adults performed a learning task in which they learned the correct response to a stimulus via feedback. Learning relevance was manipulated by varying the informational value of positive and negative feedback. To manipulate available processing resources, the task was conducted under two difficulty levels. Our results showed no hint of a positivity bias in older adults. On the contrary, we found that they learned worse when the information value of the negative feedback was reduced. This is in line with the idea that the positivity effect in older adults reflects a strategic change in motivation, i.e., older adults preferably process positive information if they have a choice, but they can process negative information as effectively when it is relevant for the task at hand. For younger adults, negative feedback seemed to be more important, too, because it modulated later higher-order feedback processing as indexed by the P3b. They showed reduced working memory updating and a more frontal P3b distribution indicating a higher processing effort in conditions in which the information value of negative feedback was reduced.