Object Ownership Processing in Peripersonal Space: An EEG Study.

Abstract

A fundamental aspect of interacting with objects in the environment is the ability to distinguish between objects that can be directly acted upon in the peripersonal space (PPS) and those out of immediate reach in the extrapersonal space (EPS). Performing appropriate actions also requires integrating social conceptual information related to who owns a particular object. While prior research has demonstrated that spatial and social factors influence object processing, how these factors are integrated is not yet fully understood. To address this issue, the present study explored the neurophysiological correlates of object ownership processing when objects were located in either the PPS or EPS. Facing a virtual character, 28 participants estimated the reachability of self-owned or other-owned objects, placed at different distances. The analysis confirmed that self-owned objects are processed faster when located in PPS, and other-owned objects are processed faster when located in EPS. EEG signals analysis revealed that early ERP components, such as the N1 and anterior N2, were modulated solely by objects' spatial location. In contrast, later components, including the P3 and anterior N400, were influenced by object ownership, although depending on object's location in space. These results suggest an early perceptual prioritization of objects in the PPS and a prioritization of objects that engages the self at a postperceptual stage. Overall, the findings provide new insights into how objects are processed depending on their spatial and social properties, and confirm that virtual reality represents a promising tool to probe neural mechanisms supporting perception and action in social contexts.