Motor Information Might be Relatively Preserved in Healthy Aging: Investigation of Body-Object Interaction

Embodied cognition holds that processing motor-related words necessitates the simulation of motor information. Numerous studies have found impairments in processing motor semantics among older adults with neurodegenerative diseases. However, the impact of healthy aging on motor semantic processing remains controversial. In this study, three experiments were conducted to investigate whether healthy aging affects motor representations and motor semantic processing, with a focus on the modulation of the degree of Body-Object Interaction (BOI) and tasks. Experiment 1 adopted a BOI rating task and revealed that ratings of healthy older adults were not significantly lower than those of younger adults. This suggested that motor representations in older adults might not be notably impaired or might be relatively preserved. Experiments 2 and 3, employing a lexical decision task and a semantic categorization task, respectively, found that healthy older adults exhibited a facilitatory BOI effect, further indicating the relative preservation of motor representations and motor simulation. Although older adults exhibited slower responses in both lexical processing tasks, this may be attributed to a decline in domain-general executive control. Overall, these experiments demonstrated that healthy aging might not lead to notable degradation in motor information. However, whether the motor semantic processing of healthy older adults is modulated by tasks still needs further exploration.