Aging and reorganization of the neural hierarchy underlying action perception: older adults prioritize affective-communicative information

Everyday action perception unfolds in complex contexts, requiring coordinated processing from low-level visual information to higher-level inferences about action types and social interactions. Aging is accompanied by sensory and cognitive changes, raising the question of how these processes may be altered. Here, we combined action similarity judgments with analyses of time-resolved and source-localized brain activity measured with magnetoencephalography (MEG) to investigate age differences in action perception when younger and older adults viewed naturalistic actions. Using cross-validated variance partitioning within a multivariate representational framework, three key findings were uncovered. First, affective-communicative features predicted similarity judgments better than, and independent of, visual and action-related features in both age groups. Second, neural processes in both groups followed a hierarchy from visual to action-related and affective-communicative features and recruited similar functional regions. However, older adults showed delayed visual processing but earlier affective-communicative processing, indicating selective prioritization rather than uniform slowing of subprocesses. Third, when sensory uncertainty was increased through visual blurring, older adults showed hierarchical reorganization, with affective-communicative features emerging earlier than action-related features, whereas younger adults preserved the original hierarchy. Together, these findings unveil adapted information prioritization in healthy aging, whereby socially meaningful information increasingly guides action perception when sensory input becomes unreliable.