Overshooting cognitive control adjustments in older age: Evidence from conflict- and error-related slowing in the Stroop, Simon, and flanker tasks

Although humans gain considerable knowledge from young to older adulthood, aging is also associated with cognitive deficits. This study investigated age-related changes in dynamic cognitive control adjustments after cognitive conflicts and errors. Specifically, we compared younger and older adults' time courses of two established phenomena - post-conflict slowing and post-error slowing. Both age groups completed modified versions of three widely used cognitive conflict tasks (Stroop, Simon, and flanker task). In these tasks, occasional incongruent information triggered a conflict that had to be resolved accordingly but sometimes elicited errors. We tracked conflict- and error-related slowing across four trials after a correct conflict trial (i.e., post-conflict slowing) and an incorrect conflict trial (i.e., post-error slowing). Post-error slowing was generally stronger than post-conflict slowing. Older adults showed a disproportionally strong slowing on the first post-error trial compared to younger adults. In contrast, on subsequent trials, older adults showed a relatively stronger speed up. This pattern of results was consistent across all three tasks. The greater cross-trial response time changes in older adults suggests a deficit in fine-tuning cognitive control adjustments.