Normal aging and motor imagery vividness: implications for mental practice training in rehabilitation

Objective: To investigate the effects of normal aging on motor imagery vividness and working memory.

Design: Descriptive study with 3 groups.

Setting: Laboratory of a university-affiliated research rehabilitation center.

Participants: A sample of healthy persons (N=80) divided into 3 age groups: young (26+/-5.0 y), intermediate (53.6+/-5.4 y), and elderly (67.6+/-4.6 y).

Interventions: Not applicable.

Main outcome measures: The kinesthetic and visual imagery scores of the Kinesthetic and Visual Imagery Questionnaire and scores from 3 domains of working memory (visuospatial, kinesthetic, verbal).

Results: Results revealed that visual motor imagery scores were higher than kinesthetic scores (imagery effect: P=.001); however, there was also a significant imagery x group interaction (P=.017). Post hoc analyses showed that only the young and intermediate groups had higher visual than kinesthetic motor imagery scores (P=.005 and .001, respectively), indicating a loss of visual motor imagery dominance in the elderly group. There was no group effect (P=.963) signifying that the level of motor imagery vividness was comparable between age groups. Significant decreases (17.3% and 22.5%, respectively) in visuospatial working memory scores were found in the intermediate (P=.011) and elderly (P=.001) groups, whereas a significant reduction (P=.01) in kinesthetic working memory scores was observed only in the elderly group (26.7%). There was also an age-related significant decline of visuospatial (r= -.50) and kinesthetic (r=-.34) working memory.

Conclusions: The level of motor imagery vividness does not diminish with age, but the quality changes. The dominance of visual motor imagery lessens with aging resulting in motor imagery modality-equivalence. These motor imagery alterations are associated with an age-related decline in visuospatial and kinesthetic working memory.