The Mental Timeline in a Crossed-Hands Paradigm.

The existence of a lateral mental timeline is well established; in left-to-right writing cultures, past is associated with the left, future with the right. Accordingly, participants respond faster with the left to past, and with the right to future. Recent studies indicate that this association does not reverse when participants respond with their hands crossed. We investigated the role of instruction for this association in a crossed-hands paradigm. Participants classified the temporal reference of words by pressing a key on the left with their right hand, or a key on the right with their left. Half of the participants were instructed to respond with their right or left hand; the other half were instructed to respond with the left or right key. An interaction between time and key showed only for participants instructed to respond with the key, providing support for the role of extracorporal space for the mental timeline.