Citation

Koul A, Soriano M, Tversky B, Becchio C, Cavallo A. Cognition 2018; 182: 213-219.

Affiliation

Department of Psychology, University of Torino, Torino, Italy; C'MoN, Cognition, Motion and Neuroscience Unit, Fondazione Istituto Italiano di Tecnologia, Genova, Italy. Electronic address: andrea.cavallo@unito.it.

Copyright

(Copyright © 2018, Elsevier Publishing)

DOI

10.1016/j.cognition.2018.10.006

PMID

30347321

Abstract

Expectations facilitate perception of expected stimuli but may hinder perception of unexpected alternatives. Here, we consider how prior expectations about others' intentions are integrated with visual kinematics over time in detecting the intention of an observed motor act (grasp-to-pour vs. grasp-to-drink). Using rigorous psychophysics methods, we find that the processes of ascribing intentions to others are well described by drift diffusion models in which evidence from observed movements is accumulated over time until a decision threshold is reached. Testing of competing models revealed that when kinematics contained no discriminative intention information, prior expectations predicted the intention choice of the observer. When kinematics contained intention information, kinematics predicted the intention choice. These findings provide evidence for a diffusion process in which the influence of expectations is modulated by movement informativeness and informative kinematics can override initial expectations.

Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Language: en

Keywords

Action observation; Drift diffusion model; Intention; Kinematics; Prior expectation