Distinct representations in occipito-temporal, parietal, and premotor cortex during action perception revealed by fMRI and computational modeling

• Published in: Neuropsychologia Vol. 127; pp. 35 - 47
• Main Authors: Urgen, Burcu A., Pehlivan, Selen, Saygin, Ayse P.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2019
• Subjects: Action perception; Brain Mapping; Cerebral Cortex - diagnostic imaging; Cerebral Cortex - physiology; Computer Simulation; Computer vision; Female; FMRI; Humans; Inferior parietal cortex; Magnetic Resonance Imaging; Male; Modeling; Motor Cortex - diagnostic imaging; Motor Cortex - physiology; Neural Networks, Computer; Occipital Lobe - diagnostic imaging; Occipital Lobe - physiology; Parietal Lobe - diagnostic imaging; Parietal Lobe - physiology; Photic Stimulation; PSTS; Psychomotor Performance - physiology; Representational similarity analysis; Temporal Lobe - diagnostic imaging; Temporal Lobe - physiology; Ventral premotor cortex; Visual Perception; Young Adult; Inferior parietal cortex; Computer vision; PSTS; Representational similarity analysis; Action perception; Modeling; FMRI; Ventral premotor cortex
• ISSN: 0028-3932; 1873-3514; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2019.02.006

Visual processing of actions is supported by a network consisting of occipito-temporal, parietal, and premotor regions in the human brain, known as the Action Observation Network (AON). In the present study, we investigate what aspects of visually perceived actions are represented in this network using fMRI and computational modeling. Human subjects performed an action perception task during scanning. We characterized the different aspects of the stimuli starting from purely visual properties such as form and motion to higher-aspects such as intention using computer vision and categorical modeling. We then linked the models of the stimuli to the three nodes of the AON with representational similarity analysis. Our results show that different nodes of the network represent different aspects of actions. While occipito-temporal cortex performs visual analysis of actions by means of integrating form and motion information, parietal cortex builds on these visual representations and transforms them into more abstract and semantic representations coding target of the action, action type and intention. Taken together, these results shed light on the neuro-computational mechanisms that support visual perception of actions and provide support that AON is a hierarchical system in which increasing levels of the cortex code increasingly complex features. •We examine what aspects of actions are represented in Action Observation Network.•Computational and categorical models of stimuli are linked to fMRI data with RSA.•pSTS performs visual analysis of actions by integrating form and motion information.•Parietal cortex codes for high-level visual and semantic aspects of actions.•Our data show that Action Observation Network is a hierarchical system.