Age-related differences in embodying a tool under visual deprivation.

Tool embodiment refers to the integration of external objects into action-related body representations. Although vision is often assumed to support this process, it remains unclear how tool use under short-term visual deprivation affects explicit ownership and agency across the adult lifespan. This study examined whether blindfolded cane use elicits subjective ownership and agency in younger and older adults, and whether these experiences are associated with forearm tactile distance perception and perceived reaching distance. Forty-three healthy right-handed adults completed two blindfolded cane-use conditions: object search training and navigation training. Tactile Distance Judgment and Reaching Distance Estimation tasks were administered before and after cane use, and participants rated ownership and agency after each condition. Across age groups and conditions, agency ratings were consistently stronger than ownership ratings. Regression analyses indicated that behavioral recalibration measures, especially Reaching Distance Estimation Error, were more consistently associated with agency than ownership, with the clearest joint-model effect observed for agency during navigation. Age Group also contributed to agency during navigation, although age-dependent interaction effects did not reach statistical significance. These findings suggest that short-term blindfolded cane use can support explicit action-based control over a tool without necessarily producing a strong conscious feeling that the tool belongs to the body. The results highlight a dissociation between explicit ownership, agency, and behavioral indices of tool-related sensorimotor updating under blindfolded tool use.