The contextual self: object ownership modulates neural encoding across peripersonal and extrapersonal spaces

A crucial aspect of interacting with objects in our environment lies in determining whether they are located within peripersonal space (PPS) - where immediate action is possible- or extrapersonal space (EPS), where objects are out of reach. Importantly, social context often prompts additional consideration of object ownership, which may interfere with spatial localization. Although previous research has demonstrated that both spatial and social contexts influence object processing, the neural networks subtending their interaction remains largely unexplored. To address this issue, the present fMRI study investigated the neural correlates of object ownership as a function of spatial location (PPS vs EPS). While facing a virtual character, 22 participants judged the reachability of self-owned or other-owned objects placed at varying distances. Results showed that objects located in the PPS activated parietal regions implicated in the sensorimotor coding of near-space stimuli, with enhanced parietal responses observed for self-owned objects, particularly in the right hemisphere. Conversely, objects in EPS engaged prefrontal regions, especially when they were self-owned. Multivariate analyses further revealed that both the ventromedial prefrontal cortex (vmPFC) and dorsomedial prefrontal cortex (dmPFC) reliably distinguished self-owned objects, with the vmPFC selectively encoding self-ownership in the PPS. These findings highlight how spatial and social dimensions jointly shape object representations in the brain, with self-relevance modulating action-related processing even in tasks focusing on spatial processing.