AbstractExemplified behaviourally in end-state comfort (ESC; Rosenbaum et al., 1990), adults typically plan intended actions in advance to minimize the costs associated with producing the action. Previous research has also demonstrated that planning and control processes are affected by action goals (e.g., pantomime vs. actual use), such that semantic information is activated only when intending to use a tool (Randerath et al., 2009). When interacting with familiar tools, however, the habitual system overrides the goal-directed system and a familiar grasp is displayed (Herbort & Butz, 2011). This study aimed to further investigate ESC in left and right handed young (Mage = 25.2, SD = 4.5) and older (Mage = 72.0, SD = 7.2) adults (N = 40) when picking up a glass (upright or overturned) to pour water in four modes of execution: (1) pantomime without a stimulus; (2) pantomime with image of the glass as a guide; (3) pantomime with glass as a guide; and (4) grasping. Young and older adults reached ceiling with the upright glass. With the overturned glass, young adults were again close to ceiling. However, older adults’ ESC increased from 73.09% in pantomime without stimulus, to 78.46% in pantomiming with image, to 88.45% pantomiming with glass, and 90% when grasping. Clearly, planning for ESC differs between healthy young and older adults. This finding has implications for our understanding of healthy aging and age-related deficits in tool use (apraxia) following stroke, which reveals how accuracy in tool use increases with more contextual information (i.e., actual tool use).
Acknowledgments: NSERC (SMS, PJB, EAR)