In a study published in the journal iScience, researchers explored whether humans could feel embodiment towards non-human-like prosthetic tools using virtual reality. The participants in the study were able to experience a sense of embodiment towards prosthetic “hands” resembling a pair of tweezers and were faster and more accurate in motor tasks when equipped with these tweezer-hands compared to a virtual human hand. It was found that humans can feel that tools are part of their body, which is essential for the seamless integration of technology with biology.
The researchers conducted a series of experiments using virtual reality on healthy participants to investigate the embodiment of bionic tools that do not resemble human anatomy. Participants were asked to perform a simple motor task of popping bubbles of a specific color using either their tweezers or their index finger and thumb. The findings showed that participants were more efficient at popping bubbles with the tweezer-hands, indicating a high level of embodiment towards these non-human-like prosthetic tools.
To further explore implicit embodiment towards the virtual hand and bionic tool, the researchers used a cross-modal congruency task where participants had to identify which fingers were stimulated while a visual stimulus was displayed on the virtual reality screen. The results showed that participants were faster and more accurate at identifying the stimulated fingers with matched tactile and visual stimuli, suggesting a sense of embodiment towards both the virtual human hand and the tweezer-hands. However, there was a greater sense of embodiment with the tweezer-hands, possibly due to their simplicity making it easier for the brain to process and accept.
The study also tested a wrench-shaped bionic tool and a virtual human hand holding tweezers, finding evidence of embodiment in all cases. Participants displayed higher embodiment and dexterity when the tweezers were grafted directly onto their virtual wrists compared to holding them in their virtual hand. Additionally, participants who had the chance to explore the virtual reality environment before the cross-modal congruency test showed a higher sense of embodiment towards the bionic tools, indicating that interactions in the virtual environment can induce a sense of agency.
The researchers suggest that these findings could have implications for robotics and prosthetic limb design. They plan to further investigate whether bionic tools can be embodied by patients who have lost limbs and study the plastic changes that such tools can induce in the brains of both healthy individuals and amputees. Understanding how humans can feel embodiment towards non-anthropomorphic prosthetic tools could lead to advancements in the development of more functional and integrated technologies for human use.
Overall, this study highlights the potential for humans to embody non-human-like prosthetic tools, paving the way for future research in the integration of technology with the human body. The findings have implications for various fields, including robotics and prosthetics, and could contribute to advancements in the design and use of bionic tools for individuals with limb loss. Further research is needed to explore the broader applications of these findings and their impact on human evolution and technological advancement.