End-state comfort in two object manipulation tasks: Investigating how the movement context influences planning in children, young and older adults


Scharoun et al., (in preparation) demonstrated that movement context (pantomime, pantomime with image/glass as guide, actual use) influences end-state comfort (ESC) planning across the lifespan. In the present study, we advanced this work in two ways. First, we tested whether we would see more ESC with a more familiar object (glass) relative to a less familiar (hammer) one. Secondly, we examined how the movement context (pantomime, using a dowel as the tool and actual use) influenced ESC planning across these two tasks. Children (ages 5-11, n=56), young (Mage = 22.9; n = 21) and older adults (Mage = 69.1; n=21) picked up an overturned glass to pour water and a hammer to hit a nail, where the handle faced away from the participant. Preliminary results revealed more ESC in actual use compared to using a dowel and in pantomime, which did not differ. In addition, more ESC was displayed in the hammer task. Age-related differences revealed less ESC in 5- to 6-year-olds compared to older participants, and in 9- to 10-year-olds compared to young adults. This supports adult-like ESC planning beyond age 10 (Wunsch et al., 2013). As a group, older adults did not differ from young adults; however, more ESC was displayed in actual use compared to pantomime in the old (70+) compared to young (60-69) older adults. This adds to our knowledge of when and at what rate motor planning skills are developing and declining and how movement context (tool use versus pantomime) affects the expression of these skills.

Acknowledgments: The authors would like to acknowledge the Natural Sciences and Engineering Research Council (SMS, PJB, and EAR), the Ontario Ministry of Training, Colleges and Universities (SMS) and the Heart and Stroke Foundation of Ontario (EAR) for funding.