RESEARCH ARTICLE Dissociable cognitive mechanisms underlying human path integration Jan M. Wiener • Alain Berthoz • Thomas Wolbers Received: 14 July 2010 / Accepted: 7 October 2010 Ó Springer-Verlag 2010 Abstract Path integration is a fundamental mechanism of spatial navigation. In non-human species, it is assumed to be an online process in which a homing vector is updated continuously during an outward journey. In contrast, human path integration has been conceptualized as a con- figural process in which travelers store working memory representations of path segments, with the computation of a homing vector only occurring when required. To resolve this apparent discrepancy, we tested whether humans can employ different path integration strategies in the same task. Using a triangle completion paradigm, participants were instructed either to continuously update the start position during locomotion (continuous strategy) or to remember the shape of the outbound path and to calculate home vectors on basis of this representation (configural strategy). While overall homing accuracy was superior in the configural condition, participants were quicker to respond during continuous updating, strongly suggesting that homing vectors were computed online. Corroborating these findings, we observed reliable differences in head orientation during the outbound path: when participants applied the continuous updating strategy, the head deviated significantly from straight ahead in direction of the start place, which can be interpreted as a continuous motor expression of the homing vector. Head orientation—a novel online measure for path integration—can thus inform about the underlying updating mechanism already during locomotion. In addition to demonstrating that humans can employ different cognitive strategies during path integra- tion, our two-systems view helps to resolve recent con- troversies regarding the role of the medial temporal lobe in human path integration. Keywords Path integration Á Cognitive strategies Á Spatial cognition Introduction Path integration, the ability to integrate perceived self- motion information over time, is a fundamental mechanism of spatial navigation. It allows for keeping track of changes in position and orientation, provides vector knowledge about places encountered during travel, and is thus assumed to play a key role in cognitive mapping (Gallistel 1990). Recent evidence from animal research, for example, suggests that path integration provides a scaffold for landmark learning (Mu ¨ller and Wehner 2010). Specifically, path integration information is combined with landmark information when novel landmarks are encoded. Even though everyday navigation strongly relies on landmark information (e.g., Newman et al. 2007), path integration appears to be an automatic process in that any perceptually signaled self-motion updates the representation of current spatial location and orientation (May and Klatzky 2000). Path integration usually interacts with landmark-based navigation (for an overview, see Etienne and Jeffery 2004) J. M. Wiener and T. Wolbers contributed equally to this manuscript. J. M. Wiener (&) Department of Psychology, Bournemouth University, Poole House, Talbot Campus, Fern Barrow, Poole, Dorset BH12 5BB, UK e-mail: jwiener@bournemouth.ac.uk J. M. Wiener Á A. Berthoz CNRS, Colle `ge de France, 75005 Paris, France T. Wolbers Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, UK 123 Exp Brain Res DOI 10.1007/s00221-010-2460-7