Neural Compensation in the Medial Prefrontal Cortex Preserves Self-Prioritization in Aging: A Computational Approach

Cognitive aging is characterized by widespread decline, yet certain fundamental processes show remarkable resilience. This study demonstrates that older adults (OAs; N = 59, 27 males, 32 females) preserve and even enhance their ability to prioritize self-related stimuli, compared with young adults (YAs; N = 32, 14 males, 18 females). Combining a perceptual matching paradigm with computational modeling and functional magnetic resonance imaging analyses, we found that this reservation operates through distinct cognitive and neural mechanisms. Drift diffusion modeling (DDM) revealed that OAs' general slower responses resulted from more conservative decision thresholds and prolonged nondecision processes (perceptual encoding and response execution), but evidence accumulation, the core computational process underlying self-prioritization, remained intact. Neuroimaging analyses showed an age-invariant self-other discrimination mediated by increased bilateral posterior superior temporal sulcus (pSTS) and decreased primary visual cortex (V1) activity. Critically, OAs demonstrated stronger brain-behavior coupling for self-prioritization than YAs in the left ventromedial prefrontal cortex (vmPFC), the right ventrolateral prefrontal cortex, the anterior cingulate cortex, and the right temporal pole (TP). Computational-neuroimaging analyses revealed two distinct preservation mechanisms: faster evidence accumulation for self-relevant information via increased vmPFC and striatum activation across age groups and heightened associations between self-information accumulation and mPFC/TP activation specific to OAs. These results demonstrate that self-prioritization preservation operates through dissociable mechanisms: neural maintenance in posterior regions mediating self-other discrimination and compensatory prefrontal-temporal recruitment sustaining behavioral performance. This dual-pathway model advances mechanistic understanding of preserved self-referential processing in healthy aging.