Study Shows Simpler Bionic Tools Boost Human Brain Integration

Photo byPhoto by Barbara Zandoval on Unsplash

Researchers have explored the potential for humans to integrate non-anthropomorphic bionic tools with their sense of using virtual reality. The study, published in iScience, investigated whether participants could experience a sense of embodiment with virtual "hands" resembling tweezers compared to a more human-like virtual hand.

In the experiments, healthy participants wore virtual tweezers or a human-like hand on their wrists. They performed tasks in a virtual environment to assess motor abilities and dexterity, finding that they were faster and more accurate with the tweezer hands. To evaluate embodiment, participants underwent a cross-modal congruency test where they identified vibrations on their actual fingers while a visual stimulus flickered on the virtual hand or tweezer. The results showed that participants experienced a sense of embodiment with both the tweezer and human-like hands, but this feeling was stronger with the tweezer hands.

The study suggests simpler bionic tools, like tweezer hands, maybe more easily integrated into the brain’s body schema than complex, human-like prostheses. This could be related to the brain’s efficiency in processing simpler, non-anthropomorphic tools or the "uncanny valley" effect, where nearly human-like but not quite perfect models are more complicated for the brain to integrate.

Additional tests with other bionic tools, like a wrench-shaped tool, showed similar results, but the most robust sense of embodiment was associated with direct integration of the tool onto the virtual wrist. Participants who explored the virtual environment before the test also displayed higher embodiment and dexterity, suggesting that interactive experiences enhance the sense of agency and integration.

These findings could influence future designs for prosthetics and robotics, potentially leading to more effective bionic tools and a better understanding of how such tools might be integrated by people who have lost limbs.