Age-related inhibitory decline: Examining inhibition subcomponents and their impact on sustained attention in healthy...

The inhibition deficit hypothesis postulates that inhibitory functioning declines with age, which negatively impacts other cognitive abilities. Yet still, the impact of healthy aging on inhibitory functioning remains unclear, with the multifaceted nature of inhibition often an overlooked factor. Moreover, no prior study has empirically tested whether inhibitory subcomponents explain differential age effects in sustained attention-an open question that this work aimed to address.

We cross-sectionally investigated the inhibition deficit hypothesis in 80 healthy older adults (M_age = 67.78 years, 44 female). We utilized the PsyToolkit platform to administer three inhibition tasks (i.e., flanker, Stroop, and go/no-go), each targeting a distinct subcomponent process, along with the Sustained Attention to Response Task.

The flanker task had low internal consistency and was deemed unreliable. Semipartial correlations of the remaining inhibition measures with age resulted in significant positive relationships with task performance on the Stroop (errors: ρ = 0.337, p = .014; reaction time: ρ = 0.313, p = .028) and a negative association with the go/no-go (balanced integrated score: ρ = -0.471, p < .001), such that older individuals had more pronounced Stroop effects and worse overall go/no-go performance. Finally, go/no-go performance completely mediated the relationship between aging and sustained attention performance (t = -2.30, 95% CI [-0.05, -0.01]), while Stroop effects partially mediated this association (t = -2.16, 95% CI [-0.03, -0.002]).

Age-related declines were observed across reliable inhibition tasks, lending support for the inhibition deficit hypothesis. The mediation findings demonstrate that inhibitory subcomponents account for age-related declines in sustained attention, over and beyond aging itself via an indirect path, representing an important cognitive domain to maintain throughout aging. (PsycInfo Database Record (c) 2026 APA, all rights reserved).