The adaptability of self-action perception and movement control when the limb is passively versus actively moved Brendan D. Cameron, Ian M. Franks, J. Timothy Inglis, Romeo Chua ⇑ School of Human Kinetics, University of British Columbia, 6081 University Blvd., Vancouver, BC, Canada V6T 1Z1 article info Article history: Received 10 June 2010 Available online 15 December 2010 Keywords: Adaptation Agency Active exposure Passive exposure Proprioception abstract Research suggests that perceptual experience of our movements adapts together with movement control when we are the agents of our actions. Is this agency critical for percep- tual and motor adaptation? We had participants view cursor feedback during elbow exten- sion–flexion movements when they (1) actively moved their arm, or (2) had their arm passively moved. We probed adaptation of movement perception by having participants report the reversal point of their unseen movement. We probed adaptation of movement control by having them aim to a target. Perception and control of active movement were influenced by both types of exposure, although adaptation was stronger following active exposure. Furthermore, both types of exposure led to a change in the perception of passive movements. Our findings support the notion that perception and control adapt together, and they suggest that some adaptation is due to recalibrated proprioception that arises independently of active engagement with the environment. Ó 2010 Elsevier Inc. All rights reserved. 1. Introduction For most of our daily actions we spend little time consciously thinking about the locations of our various body parts or how to make these body parts do the things we want them to do. Our sensorimotor system seems to effortlessly draw upon visual, proprioceptive, and vestibular feedback, and probably even upon knowledge of its foregoing commands, to update its estimates of limb and body position and then to fluidly guide our actions. The system is also highly flexible, for it can adapt motor output when we encounter novel environments. If the dynamics of a limb are altered or if visual feedback is distorted, accurate performance can be reacquired after repeated exposure to the distortion (e.g., Krakauer, Pine, Ghilardi, & Ghez, 2000; Shadmehr & Mussa-Ivaldi, 1994; Welch, 1986). What processes drive this motor adaptation and what is the relation- ship between motor adaptation and our perceptual sense of limb position? One influential model for motor adaptation suggests that the sensorimotor system uses a copy of an outgoing motor com- mand (an efference copy) to make a prediction about forthcoming sensory feedback, a process called forward modeling (Tseng, Diedrichsen, Krakauer, Shadmehr, & Bastian, 2007; Wolpert & Ghahramani, 2000). To the extent that the prediction fails to match the actual sensory outcome, motor updating and forward model updating are required. A similar mechanism is thought to underlie our attribution of agency to our actions (Cullen, 2004): If a comparison of predicted sensory feedback to actual sensory feedback produces a match, we attribute the action to ourselves, while a mismatch suggests that an external force has generated, or at least influenced, the sensory feedback. 1 1053-8100/$ - see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.concog.2010.11.006 ⇑ Corresponding author. Fax: +1 604 822 6842. E-mail address: romeo.chua@ubc.ca (R. Chua). 1 The notion that an efference copy might be involved in differentiating self-generated from external feedback was originally developed by Von Holst and Mittelstaedt (1950) and subsequently elaborated to incorporate the concept of a forward model and a broader sense of action agency by Frith and colleagues (Frith, Blakemore, & Wolpert, 2000). Consciousness and Cognition 21 (2012) 4–17 Contents lists available at ScienceDirect Consciousness and Cognition journal homepage: www.elsevier.com/locate/concog