What tool representation, intuitive physics, and action have in common: The brain's first-person physics engine

Abstract

An overlapping set of brain regions in parietal and frontal cortex are engaged by different types of tasks and stimuli: (i) making inferences about the physical structure and dynamics of the world, (ii) passively viewing, or actively interacting with, manipulable objects, and (iii) planning and execution of reaching and grasping actions. We suggest the observed neural overlap is because a common superordinate computation is engaged by each of those different tasks: A forward model of physical reasoning about how first-person actions will affect the world and be affected by unfolding physical events. This perspective offers an account of why some physical predictions are systematically incorrect - there can be a mismatch between how physical scenarios are experimentally framed and the native format of the inferences generated by the brain's first-person physics engine. This perspective generates new empirical expectations about the conditions under which physical reasoning may exhibit systematic biases.

Keywords: Physics engine; forward model; grasping; supramarginal gyrus; tool representation.

Figure 1.. A common network of brain regions supports manipulable object representation, intuitive physics inferences, and action planning.

A) Regions in parietal and frontal cortex that are engaged during intuitive physics inferences (Fischer, 2020) (Navarro-Cebrian & Fischer, 2022). Those regions are more active during physical prediction than during difficulty-matched tasks requiring prediction in other domains (Fischer et al., 2016). B) The network that is more active during viewing of manipulable objects compared to animals, places and faces (for the original observation, see (Chao & Martin, 2000); these data from (Kristensen, Garcea, Mahon, & Almeida, 2016). C) Regions engaged in reaching and grasping , from (Culham et al., 2003) see also (Gallivan & Culham, 2015). While the task demands and stimuli used to localize the three networks are markedly different on their surface, they engage overlapping parietal and frontal areas. Of particular note, is the role of the supramarginal gyrus across intuitive physics, manipulable object representation, action planning and execution, and (not shown) phonological processing (M. Oberhuber, 2016).