Disconnected hand avatar can be integrated into the peripersonal space

Remote hand: Hand-centered peripersonal space transfers to a disconnected hand avatar

“…When the hand avatar was presented in far space, multi-modal facilitation was higher at the far space than at the normal (near-hand) position. Thus, as previously shown by Mine and Yokosawa (2020), HPPS appeared around the disconnected hand avatar. Furthermore, multi-modal facilitation was higher at the far space than at the middle space, suggesting that HPPS emerged around the disconnected hand avatar rather than extended from the space around the participant's real hand.…”

“…More interestingly, for the far-hand condition, the multi-modal facilitation effect was significantly higher at D1 compared to D2 and D3, and the difference between D2 and D3 was not significant (D1 versus D2: t(26) = 2.96, p = .0065, d = .569; D1 versus D3: t(26) = 2.45, p = .021, d = .471; D2 versus D3: t(26) = 0.49, p = .63, d = .094). This pattern of results represents a successful replication of Mine and Yokosawa (2020) and further suggests that, when the hand avatar was placed in the space far from the participant's body, HPPS emerged around the hand avatar. Furthermore, simple effects analyses of hand position for each visual stimulus position revealed significant effects at D1 and D3 but not at D2 (D1: F(1, 26) = 4.72, p = .039, ! "…”

“…PPS representations when individuals control these remotely controlled avatars or modified bodies have not yet been fully investigated. A previous research revealed that HPPS appears around a hand avatar that is disconnected and presented far from the body in a virtual environment; however, HPPS representation was investigated only in the space around the disconnected hand avatar, but not around the participant's real hand or in the intermediate space between the participant's real hand and the disconnected hand (Mine & Yokosawa, 2020). In the present study, we investigated HPPS representation when individuals experienced a disconnected hand avatar that could be controlled through the movement of their own hand in a virtual environment.…”

“…The first is whether HPPS appears around the disconnected hand avatar. Mine and Yokosawa (2020) used a line-bisection task to reveal that HPPS can appear around the disconnected hand (see Jewell & McCourt, 2000;McCourt & Garlinghouse, 2000;Varnava, McCarthy, & Beaumont, 2002). The linebisection task has been used as a measurement of HPPS, but because the neural mechanisms relevant to the task are not yet fully understood, it is unknown whether performance of the line-bisection task is really based on the activation of multi-modal neurons.…”

“…The fourth hypothesis, the no-change model, is that HPPS representation does not change when the disconnected hand is used (Fig 1d). If the results of Mine and Yokosawa (2020) can be replicated, HPPS should appear around the disconnected hand; however, Mine and Yokosawa (2020) did not investigate HPPS representation around the real hand or around the intermediate space between the real hand and disconnected hand.…”