Sensory brain responses rise with age as cognitive ones decline

In 40 older adults aged 60 to 81 and 37 younger adults aged 18 to 25, researchers mapped whole-brain activity using magnetoencephalography during an auditory local-global paradigm. Participants listened to tone sequences designed to trigger both local sensory violations and global pattern-based violations.

Using principal component analysis on 3,559 reconstructed brain sources, the team separated three overlapping neural networks. Early sensory deviance responses within a network spanning auditory and medial cingulate cortices were enhanced in older adults compared to younger adults. Specifically, older adults showed larger local mismatch negativity and P3a responses. In contrast, later and more cognitively demanding responses, including reorienting negativity and global prediction error responses, were attenuated in older participants. Across both groups, network recurrence remained preserved, indicating that aging selectively redistributes predictive responses rather than broadly impairing them.