The differential effect of age on upper limb sensory processing, proprioception and motor function.

Abstract

Sensory processing consists in the integration and interpretation of somatosensory information. It builds upon proprioception but is a distinct function requiring complex processing by the brain over time. Currently little is known about the effect of aging on sensory processing ability, nor the influence of other covariates such as motor function, proprioception, or cognition. In this study, we measured upper limb passive and active sensory processing, motor function, proprioception, and cognition in 40 healthy younger adults and 54 older adults. We analyzed age differences across all measures and evaluated the influence of covariates on sensory processing through regression. Our results showed larger effect sizes for age differences in sensory processing (r=0.38) compared to motor function (r=0.18-0.22) and proprioception (r=0.10-0.27), but smaller than for cognition (r=0.56-0.63). Aside from age, we found no evidence that sensory processing performance was related to motor function or proprioception, but active sensory processing was related to cognition (β=0.30-0.42). In conclusion, sensory processing showed an age-related decline, while some proprioceptive and motor abilities were preserved across age.