Does metarepresentation make human mental time travel unique?

UNLABELLED: Recent neurological evidence suggests that rats can mentally represent novel spatial trajectories and then are more likely to follow these paths in the future. Consequently, it has been proposed that human and nonhuman mental time travel capacities may differ in degree rather than kind. As of yet, however, there is no evidence for the crucial and qualitatively distinct component of metarepresentation in any nonhuman animal, not even our closest great ape relatives. Metarepresentation allows humans to represent the relationship between current reality and mere representations of reality-including those of the future. Drawing on parallels with dreaming and mind-wandering, I outline the future-oriented benefits associated with uncontextualized (non-metarepresentational) representations of past and novel events, but propose that further, immense benefits flowed from the addition of metarepresentational insight. I critique previous behavioral paradigms used to assess mental time travel in animals and suggest how future-oriented metarepresentation might possibly be demonstrated nonverbally. WIREs Cogn Sci 2014, 5:519-531. doi: 10.1002/wcs.1308 For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article.