Effects of physical disability on the sensitivity and criterion of sense of agency

The sense of agency—namely, the feeling that one’s actions are self-initiated and controllable—is fundamental to how individuals understand themselves and engage with the world. Although often taken for granted, this experience may be altered by physical disability. The present study examined differences in the sense of agency between healthy adults and individuals with physical impairments using a movement-based dot trajectory task. Two indices—sensitivity (slope) and decision criterion (point of subjective equality)—were derived from logistic regression modeling. The results showed that individuals with physical disabilities not only had blurred between self-other distinction, but also attributed actions to themselves without justification, indicating blurred self-other boundaries. Notably, the observed alteration was not attributable to age or physical activity levels, and no significant associations were observed with psychological state or caregiving needs. These findings suggest that physical limitations themselves, irrespective of mental health or daily activity, may reshape how individuals perceive control over their own actions. Understanding such shifts in self-perception could have important implications for rehabilitation strategies and for improving quality of life in populations with physical impairments.