The unique role of parietal cortex in action observation: Functional organization for communicative and manipulative actions

Abstract

Action observation is supported by a network of regions in occipito-temporal, parietal, and premotor cortex in primates. Recent research suggests that the parietal node has regions dedicated to different action classes including manipulation, interpersonal interactions, skin displacement, locomotion, and climbing. The goals of the current study consist of: 1) extending this work with new classes of actions that are communicative and specific to humans, 2) investigating how parietal cortex differs from the occipito-temporal and premotor cortex in representing action classes. Human subjects underwent fMRI scanning while observing three action classes: indirect communication, direct communication, and manipulation, plus two types of control stimuli, static controls which were static frames from the video clips, and dynamic controls consisting of temporally-scrambled optic flow information. Using univariate analysis, MVPA, and representational similarity analysis, our study presents several novel findings. First, we provide further evidence for the anatomical segregation in parietal cortex of different action classes: We have found a new site that is specific for representing human-specific indirect communicative actions in cytoarchitectonic parietal area PFt. Second, we found that the discriminability between action classes was higher in parietal cortex than the other two levels suggesting the coding of action identity information at this level. Finally, our results advocate the use of the control stimuli not just for univariate analysis of complex action videos but also when using multivariate techniques.

The human posterior cingulate, retrosplenial, and medial parietal cortex effective connectome, and implications for memory and navigation

“…Unlike Group 2 regions, the Group 3 regions have connectivity with somatosensory cortex (5), and have no connectivity with the frontal cortex. The Group 3 regions thus appear to be involved in relatively low‐level visual processing, with connectivity with the superior parietal cortex area 7 which suggests that the Group 3 regions are involved in visuo‐motor control appropriate for motor actions in visual space (Andersen, 1995 ; Huang & Sereno, 2018 ; Orban et al, 2021 ; Rolls et al, 2022a , 2022d ; Urgen & Orban, 2021 ), and perhaps in the necessary spatial coordinate transforms (Rolls, 2020 ; Salinas & Sejnowski, 2001 ). Indeed, spatial coordinate transforms are also necessary for idiothetic update of spatial representations useful for hippocampal function including navigation when the spatial view is obscured (Dean & Platt, 2006 ; Rolls, 2020 , 2021b , 2022b ; Snyder et al, 1998 ; Vedder et al, 2017 ).…”

Action goals and the praxis network: an fMRI study

“…When actions motivated by disparate goals were considered, they usually involved simple non-functional objects, such as wooden or plastic blocks, with either simple or irregular shapes (Króliczak et al 2008 ; Cavina-Pratesi et al 2010 ; Monaco et al 2011 ; Gallivan et al 2013 ; Marangon et al 2016 ). Conversely, when common tools or objects and different actions directed toward them were investigated, it was done primarily in the context of hand posture/action recognition (Buxbaum et al 2006 ; Handjaras et al 2015 ), action observation (Platonov and Orban 2017 ; Orban et al 2019 ; Urgen and Orban 2021 ) or imagining of the goal-appropriate hand/finger postures (Vingerhoets et al 2009 , 2013 ). To the best of our knowledge, the only two studies thus far (Garcea and Buxbaum 2019 ; Malfatti and Turella 2021 ), which successfully addressed some differences in neural representations of pantomimed performance of tool-related actions with distinct goals, utilized functional connectivity modeling, and multi-voxel pattern analysis (MVPA) to show consistent signal modulations and their directions in tool/action processing streams, or their decoding capabilities of the goal or general use components of such actions.…”

Two distinct networks containing position-tolerant representations of actions in the human brain

“…In the domain of observed actions, despite the large body of literature that identifies regions in the occipitotemporal and parietal cortices that respond to (Casper et al, 2010;Kalenine et al, 2010;Grosbras et al, 2012;Watson et al, 2013;Urgesi et al, 2014) and contain information about (e.g., Wheaton et al, 2004;Jastorff et al, 2010;Abdollahi et al, 2013;Lignau and Downing, 2015;Ferri et al, 2015;Hafri et al, 2017;Wurm et al, 2017b;Urgen et al, 2019;Tucciarelli et al, 2019;Tarhan and Konkle, 2020;Urgen and Orban, 2021) observed actions, (which was not certified by peer review) is the author/funder. All rights reserved.…”