ORIGINAL ARTICLE Normal Aging and Motor Imagery Vividness: Implications for Mental Practice Training in Rehabilitation Francine Malouin, PhD, Carol L. Richards, PhD, Anne Durand, PhD ABSTRACT. Malouin F, Richards CL, Durand A. Normal aging and motor imagery vividness: implications for mental prac- tice training in rehabilitation. Arch Phys Med Rehabil 2010;91: 1122-7. 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 reha- bilitation center. Participants: A sample of healthy persons (N=80) divided into 3 age groups: young (265.0y), intermediate (53.65.4y), and elderly (67.64.6y). Interventions: Not applicable. Main Outcome Measures: The kinesthetic and visual im- agery scores of the Kinesthetic and Visual Imagery Question- naire and scores from 3 domains of working memory (visuo- spatial, 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  group inter- action (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), indi- cating 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 alter- ations are associated with an age-related decline in visuospatial and kinesthetic working memory. Key Words: Aging; Rehabilitation. © 2010 by the American Congress of Rehabilitation Medicine O VER THE PAST DECADE, mental practice through mo- tor imagery has proved beneficial as an adjunct therapy for improving motor function after stroke, brain and spinal cord injuries, and Parkinson’s disease and for alleviating phantom pain. 1,2 Motor imagery is an active process during which the representation of an action is internally reproduced within working memory without any overt output. 3 These internal representations of motor actions are centrally organized and like other representations are stored, modified, and may be retrieved through specific cognitive processes. 4 Several exper- imental investigations have shown that physically executed and internally simulated motor actions share similarities at the neural and functional level. For instance, the movement times of mentally simulated tasks such as walking, arm pointing, and writing are similar to their real execution times, indicating that motor representations share similar temporal characteristics and obey the same motor rules as their actual counterparts. 5,6 Moreover, imagined and executed actions induce analogous physiologic autonomic responses, 4,7 and brain imaging studies have shown that motor imagery activates brain networks that greatly overlap with those activated by real movements. 8,9 The neurocognitive similarities between actual and simu- lated motor actions have been largely documented in young healthy adults. Because the ability to form internal representa- tions of motor actions is necessary for training with mental practice and that its use in rehabilitation involves aging popu- lations, it is important to investigate how motor imagery ability is modulated with normal aging. The few studies 10-14 that have examined the effect of normal aging on motor imagery pro- cesses suggest a decline in explicit and implicit motor imagery with normal aging. For instance, studies investigating the in- fluence of age on temporal characteristics of real and simulated movements found deterioration in timing accuracy particularly in motor tasks implying either spatiotemporal (speed-accuracy trade-off paradigm) or dynamic (varying gravity-inertial con- text) constraints. 10-13 Likewise, elderly persons were affected in their ability to implicitly simulate movements of the hands, especially those requiring the largest amplitude of displace- ment and/or with strong biomechanical constraints. 14 Aging has selective effects on mental imagery; more specif- ically, accessing and activating stored visual memories are particularly deteriorated in the elderly. 15,16 Earlier studies 15,16 have also shown that the generation and manipulation of men- tal images is more difficult with aging and that these age- related deficits are likely associated with a decline in working memory. 15,16 Little is known, however, about the influence of From the Department of Rehabilitation, Laval University and Center for Interdis- ciplinary Research in Rehabilitation and Social Integration (Malouin, Richards), the Institut de Réadaptation en Déficience Physique de Québec (Durand), Quebec City, QC, Canada. Supported by Quebec Provincial Rehabilitation Research Network and the Canadian Institutes of Health Research. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organi- zation with which the authors are associated. Reprint requests to Francine Malouin, PhD, Center for Interdisciplinary Research in Rehabilitation and Social Integration, IRDPQ, 525 Blvd Hamel East, Quebec City, QC, Canada, G1M 2S8, e-mail: Francine.Malouin@rea.ulaval.ca. Published online May 31, 2010 at www.archives-pmr.org. 0003-9993/10/9107-00891$36.00/0 doi:10.1016/j.apmr.2010.03.007 List of Abbreviations ANOVA analysis of variance KVIQ Kinesthetic and Visual Imagery Questionnaire 1122 Arch Phys Med Rehabil Vol 91, July 2010