Rethinking the Mind’s Brakes: Inhibition Is Not One Skill but Many

Every time you ignore a buzzing phone, stop yourself from blurting out a thought, or switch strategies when a plan stops working, you are relying on executive functions: the brain’s control systems for regulating cognition, behavior, and emotion in the service of goals. For more than three decades, psychologists have debated how these functions are organized. Are they one unified mental resource, or a family of partly independent processes that cooperate only when a task demands it? A new study published in Trends in Psychology by María Fernanda López-Ramón of the University of Valencia and colleagues in Spain and Argentina tackles this question with an unusual degree of precision, and its answer challenges the way inhibition has traditionally been measured.

The dominant modern framework, shaped by landmark work from Miyake and colleagues in 2000 and refined by Adele Diamond and others, treats executive functions as a multidimensional construct with three core components: working memory, cognitive flexibility, and inhibition. Working memory stores and manipulates information in the moment; cognitive flexibility allows thoughts and actions to shift when circumstances change; inhibition suppresses irrelevant stimuli, intrusive thoughts, or premature responses. Yet while this tripartite view is widely accepted, most studies have treated inhibition as a single, unitary quantity, measured with one task and entered into models as one number. That shortcut, the new research argues, has obscured crucial structure.

Cognitive psychologists such as Harnishfeger and Nigg long ago proposed that inhibition is itself multidimensional, comprising at least three distinct processes that differ in the level of mental representation they act upon and the stage of processing at which they operate. Perceptual inhibition works at the earliest stage, dampening the activation of representations triggered by distracting stimuli in the environment, a function sometimes called interference control or attentional inhibition. Cognitive inhibition operates deeper into processing, suppressing unnecessary or intrusive memories and thoughts that could otherwise hijack attention. Response inhibition intervenes latest of all, in the moments before an action is emitted, holding back automatic or habitual motor responses that conflict with current goals. The new study is, to the authors’ knowledge, the first to test competing models of how the major executive functions relate to one another while explicitly separating these inhibitory types.

The researchers recruited 313 young adults aged 17 to 20, students at the University of Valencia who volunteered and completed computerized cognitive tasks in supervised group sessions. This developmental window was chosen deliberately: executive functions reach their peak of efficiency in early adulthood, yet few studies have mapped their interrelationships at precisely this stage, when processes may be becoming increasingly specialized. Participants completed three tasks from the TAC battery, a computer-based assessment system, with reaction time and accuracy recorded on every trial. The sessions lasted forty-five minutes each, and data collection continued over three months in groups of thirty to forty participants.

Perceptual inhibition was assessed with a conjunctive visual search task, in which participants hunted for a blue square among red squares and blue circles. Because every distractor shared one feature with the target, the task guarantees visual interference, and the efficiency of perceptual inhibition was indexed by the difference in response time between a no-distractor baseline condition and a condition with four distractors. Response inhibition and cognitive flexibility were both measured with the Finger Task, a Simon-type paradigm in which hand icons appear on the left or right of a screen. In congruent blocks, participants respond on the same side as the stimulus; in incongruent blocks, they must suppress that dominant tendency and respond on the opposite side, and the performance gap between blocks indexes response inhibition. A mixed block, requiring alternation between the two rules, provided the switching-cost measure of cognitive flexibility. Visuospatial working memory was assessed with a dual task in which participants recalled the positions of colored crosses in a four-by-four matrix while simultaneously naming colors in a secondary interference task.

With these measures in hand, the team used structural equation modeling with maximum likelihood estimation to compare two theoretical architectures. The first, rooted in the inhibitory framework of Hasher and colleagues, proposes a mediated cascade: inhibitory processes safeguard the limited resources of working memory by filtering out irrelevant information, and working memory in turn supports cognitive flexibility. On this view, individual differences in inhibitory efficiency are the primary engine of variation across all executive tasks. The second, based on Diamond’s model, proposes a flatter, inclusive architecture in which inhibition and working memory are relatively distinct processes that both contribute to cognitive flexibility. The researchers also tested a constrained variant that removed working memory entirely, to verify its contribution to the fuller model.

The results were revealing. Both main models fit the data well, but the inclusive, non-mediated architecture corresponding to Diamond’s framework provided the best fit, and the constrained model without working memory failed outright, confirming that working memory belongs in any adequate account. Within the winning model, a significant relationship emerged between response inhibition and visuospatial working memory: participants who were faster and more accurate at suppressing the dominant response tendency also performed better on the working memory span task. This finding echoes the inhibitory theory’s central claim that controlling impulses and inappropriate responses frees processing resources for maintaining and manipulating information. Yet perceptual inhibition showed no such link to working memory, and the two inhibitory processes were themselves uncorrelated, evidence that they operate as relatively independent mechanisms rather than expressions of a single inhibitory faculty.

Perhaps the most striking result was what did not appear. Neither inhibitory process showed a direct effect on cognitive flexibility performance in this sample. The authors interpret this absence through the lens of developmental specialization: in early adulthood, when executive functions reach their operational peak, they may also reach maximal differentiation, so that complex abilities like task switching draw on underlying processes in ways that are too specific to register as simple direct paths. The study’s models explained a modest share of the variance in flexibility, a reminder that single experimental tasks, with their well-known impurity, capture only part of any executive construct. The authors are candid about limitations, including the non-probabilistic sample, the underrepresentation of men, the use of a single task per construct, and the omission of cognitive inhibition, the third inhibitory process, which future work should incorporate alongside other age groups.

Even with those caveats, the implications are substantial. If inhibition is multidimensional, then studies that collapse it into one measure are averaging away real structure, potentially explaining why the literature on executive function relationships has produced inconsistent findings. Training programs, clinical assessments, and educational interventions that target inhibition may need to specify which inhibition they mean: suppressing a distracting sight, dismissing an intrusive thought, and withholding an impulsive action are separable skills, and the new data suggest they do not travel together. The finding that response inhibition, but not perceptual inhibition, tracks working memory performance offers a concrete, testable bridge between two of psychology’s most studied constructs. As the authors conclude, analyzing inhibition through a genuinely multidimensional lens, rather than as a monolithic brake on behavior, is essential for understanding how the mind’s control systems are wired, and the present study provides one of the clearest demonstrations yet of why that distinction matters.

Subject of Research: The relationships among executive functions, including distinct inhibitory processes, working memory, and cognitive flexibility in young adults

Article Title: Executive Functions Interplay: A Multidimensional Model Including Different Inhibitory Processes

Article References: López-Ramón, M. F., Richard´s, M. M., Musso, M. F., Aydmune, Y., Bario, D., & Introzzi, I. M. (2026). Executive Functions Interplay: A Multidimensional Model Including Different Inhibitory Processes. Trends in Psychology. https://doi.org/10.1007/s43076-025-00511-6

Image Credits: AI Generated

DOI: 10.1007/s43076-025-00511-6

Keywords: executive functions, inhibition, working memory, cognitive flexibility, perceptual inhibition, response inhibition, structural equation modeling, young adults, cognitive psychology, attention, self-regulation, Trends in Psychology