Evidence for response inhibition as a control process distinct from the common executive function: A two-study factor analysis.

Abstract

The dominant model of executive functions, which has held for over two decades, contends that various aspects of seemingly disparate forms of inhibitory control—for example, inhibiting a prepotent response, or inhibiting irrelevant thoughts and distractions—are in fact manifestations of a single latent executive function. Recent work, however, has cast doubt on this dominant model, as certain conditions can dissociate performance on tasks thought to index inhibitory control. Moreover, issues related to task reliability and latent estimation of inhibition processes have prompted questions about whether the structure of inhibitory control can even be reliably estimated at a latent level. We addressed these issues in two studies of healthy young adults (Study 1 N = 154, Study 2, N = 279), examining seven then 12 different tasks taken by prior research to assess inhibitory control. Contrary to the dominant model of executive functions, we found that, at a latent level, inhibitory control was best fit by a replicable two-factor solution, with response inhibition as a distinct executive function. Further, our data suggested that prior work on executive functions may not have observed a response inhibition factor due to task selections (i.e., including either one of two specific tasks was critical to identifying a separate response inhibition factor). Therefore, contrary to the current primary theoretical model of executive functions, these results suggest that response inhibition is, in fact, a distinct control process from the control process underpinning other forms of inhibition, which has important implications for designing interventions and assessing outcomes related to inhibitory control.