Does global slowing explain age effects in inhibitory control?

A long-standing debate in the study of cognitive aging concerns whether aging results in a selective deficit in inhibitory control beyond a general slowing of cognitive processing. Previous studies have obtained mixed findings, in part because the typical free response time paradigm lacks the specificity required to disentangle component processes underlying inhibitory control. Here, we apply a novel forced-response paradigm and a computational model to disentangle these processes to test if aging results in overall speed differences or a selective deficit in inhibitory control. 50 older adults and 57 younger adults completed a “forced-response” arrow flanker task. We find strong evidence that older adults demonstrate a global slowing of processing, without any selective deficit in inhibitory control. Furthermore, we demonstrate global slowing is sufficient to explain the mixed findings in previous free RT studies. Overall, these results highlight the utility of using a theory-informed, fine-grained approach to study inhibitory control.