Processing efficiency predicts cognitive performance in aging

Cognitive decline is a central challenge of aging, with subtle early changes laying the foundation for broader difficulties later in life. One domain that is particularly challenging to capture with standard assessments is processing efficiency. Previous research has shown age-related differences in processing efficiency using redundant-target detection tasks, but it remains unclear whether individual differences in cognitive ability within the older adults are associated with differences in processing efficiency. In the present study, 65 cognitively healthy older adults (aged 60-79) completed the Montreal Cognitive Assessment (MoCA) and a color-shape redundant-target detection task, from which we estimated resilience capacity (Rz), a processing efficiency metric that quantifies how well a system maintains its target processing speed in the presence of distractors, using Systems Factorial Technology (SFT). MoCA scores were significantly and positively correlated with the standardized resilience capacity summary, Rz (r = 0.35, 95%CI [0.12, 0.55], p = 0.004). This significant association persisted in a partial correlation analysis that controlled for age as a covariate (partial r = 0.35, p = 0.004). In a direct model comparison of four candidate processing-efficiency metrics - inverse efficiency scores (IES), redundancy gains (RG), mean RT of correct responses, and Rz - Rz was the strongest predictor of MoCA. Functional principal component analysis (fPCA) of R(t) identified a temporal component (PC2) on which individuals at the higher end of the MoCA distribution showed a later, more controlled rise in capacity, whereas those at the lower end showed earlier but less efficient processing. Together, these findings indicate that processing efficiency metric - and specifically resilience capacity under distractor interference - is continuously related to cognitive performance in older adults and may reflect aspects of cognitive reserve not captured by global screening scores or summary-statistic-based efficiency measures.