Brain Network Dynamics of Local and Global Predictive Processing in Aging.

Cognitive aging is widely associated with a progressive weakening of neural responses associated with predictive brain mechanisms. This view is supported by decades of electrophysiological studies reporting attenuated mismatch responses in older adults. Yet the literature remains inconsistent, suggesting that aging may not uniformly attenuate such responses. One possibility is that aging exerts differential effects depending on task demands. Here we aim to separate whole-brain networks underlying deviance processing in source-reconstructed magnetoencephalography (MEG) data from 37 younger and 40 older adults performing the auditory local-global paradigm. Network decomposition revealed three temporally overlapping subsystems. Aging exerted selective effects across these networks. Early sensory deviance responses were enhanced within a network recruiting auditory cortices and medial cingulate regions, whereas later cognitive processes were attenuated in older adults. The level of multivariate recurrence across these networks was preserved with aging, while the processing of sensory violations induced more recurrence and less divergence relative to pattern-based violations in both groups. This age-related increase in sensory-related mismatch responses challenges the prevailing view that sensory deviance processing simply declines with age. These results suggest that in aging, neural responses may be differentially distributed across distinct neural systems, amplifying sensory-based processes while weakening cognitively demanding mechanisms.