Acquisition, representation, and transfer of models of visuo-motor error Hang Zhang $ Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China Peking-Tsinghua Center for Life Sciences, Beijing, China Department of Psychology, New York University, New York, NY, USA Center for Neural Science, New York University, New York, NY, USA Institute for the Interdisciplinary Study of Decision Making, New York University, New York, NY, USA Mila Kirstie C. Kulsa $ Department of Psychology, New York University, New York, NY, USA Laurence T. Maloney $ Department of Psychology, New York University, New York, NY, USA Center for Neural Science, New York University, New York, NY, USA Institute for the Interdisciplinary Study of Decision Making, New York University, New York, NY, USA We examined how human subjects acquire and represent models of visuo-motor error and how they transfer information about visuo-motor error from one task to a closely related one. The experiment consisted of three phases. In the training phase, subjects threw beanbags underhand towards targets displayed on a wall-mounted touch screen. The distribution of their endpoints was a vertically elongated bivariate Gaussian. In the subsequent choice phase, subjects repeatedly chose which of two targets varying in shape and size they would prefer to attempt to hit. Their choices allowed us to investigate their internal models of visuo-motor error distribution, including the coordinate system in which they represented visuo-motor error. In the transfer phase, subjects repeated the choice phase from a different vantage point, the same distance from the screen but with the throwing direction shifted 458. From the new vantage point, visuo-motor error was effectively expanded horizontally by ffiffi 2 p . We found that subjects incorrectly assumed an isotropic distribution in the choice phase but that the anisotropy they assumed in the transfer phase agreed with an objectively correct transfer. We also found that the coordinate system used in coding two- dimensional visuo-motor error in the choice phase was effectively one-dimensional. Introduction People compensate—in part—for unavoidable noise in their perceptual and motor systems. Studies typically find that human decisions in reaching tasks are close to those predicted by Bayesian decision theory, maximiz- ing expected Bayes gain (Battaglia & Schrater, 2007; Faisal & Wolpert, 2009; Hudson, Maloney, & Landy, 2008; Jazayeri & Shadlen, 2010; K ¨ ording & Wolpert, 2004; Trommersh ¨ auser, Landy, & Maloney, 2006; Trommersh ¨ auser, Maloney, & Landy, 2003; Wei & K ¨ ording, 2010). This near-optimal performance could be taken as evidence that human subjects have an objectively correct internal model of their own random motor errors. However, Zhang, Daw, and Maloney Citation: Zhang, H., Kulsa, M. K. C., & Maloney, L.T. (2015). Acquisition, representation, and transfer of models of visuo-motor error. Journal of Vision, 15(8):6, 1–15, doi:10.1167/15.8.6. Journal of Vision (2015) 15(8):6, 1–15 1 doi: 10.1167/15.8.6 ISSN 1534-7362 Ó 2015 ARVO Received January 21, 2015; published June 9, 2015 Downloaded From: http://jov.arvojournals.org/pdfaccess.ashx?url=/data/Journals/JOV/934120/ on 06/16/2015