The role of canonical hand representations and spatiolateral semantics in mental rotation of hands

Previous studies on the mental representation of body parts have shown that both proprioceptive information and canonical images of hands affect the mental motor imagery of one’s own hands. In two mental hand-rotation experiments in which verbal responses were required, we addressed the role of the semantics of laterality in manipulating canonical images of hands. The results suggested that oral responses that recruited the words ‘‘right’’ or ‘‘left’’ facilitated the use of canonical representations of hands in performing the motor imagery. In contrast, responses entailing arbitrary sounds ‘‘ke’’ or ‘‘to’’ resulted in stable effects of the postural information provided by participants’ own hands, indicating that canonical hand images were not used (indicated that participants relied primarily on the proprioceptive information of their actual hands). The findings support our assumption that spatiolateral semantics underpin the use of canonical hand representations in certain mental processes.