title: Action perception as hypothesis testing.
abstract: We present a novel computational model that describes action perception as an active inferential process that combines motor prediction (the reuse of our own motor system to predict perceived movements) and hypothesis testing (the use of eye movements to disambiguate amongst hypotheses). The system uses a generative model of how (arm and hand) actions are performed to generate hypothesis-specific visual predictions, and directs saccades to the most informative places of the visual scene to test these predictions - and underlying hypotheses. We test the model using eye movement data from a human action observation study. In both the human study and our model, saccades are proactive whenever context affords accurate action prediction; but uncertainty induces a more reactive gaze strategy, via tracking the observed movements. Our model offers a novel perspective on action observation that highlights its active nature based on prediction dynamics and hypothesis testing.
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Donnarumma
authors.affiliation: Centre for Brain Science, Department of Psychology, University of Essex, Colchester, UK; Laboratory of Neuropsychology and Cognitive Neuroscience, Department of Neuroscience and Imaging, University G. d'Annunzio, Chieti, Italy; Institute for Advanced Biomedical Technologies - ITAB, Foundation University G. d'Annunzio, Chieti, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Costantini
authors.affiliation: Department of Neuroscience, University of Padua, Padua, Italy; Laboratory of Neuropsychology and Cognitive Neuroscience, Department of Neuroscience and Imaging, University G. d'Annunzio, Chieti, Italy; Institute for Advanced Biomedical Technologies - ITAB, Foundation University G. d'Annunzio, Chieti, Italy.
authors.forename: Ettore
authors.initials: E
authors.lastname: Ambrosini
authors.affiliation: The Wellcome Trust Centre for Neuroimaging, UCL, London, UK.
authors.forename: Karl
authors.initials: K
authors.lastname: Friston
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy. Electronic address: giovanni.pezzulo@istc.cnr.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pezzulo
mesh_terms: D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D033182:Intention; D008962:Models, Theoretical; D009039:Motion Perception / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D056345:Theory of Mind / Q000502:physiology*
keywords: Action observation; Active inference; Active perception; Hypothesis testing; Motor prediction