The robot hand illusion: inducing proprioceptive drift through visuo-motor congruency

Area of Science:

• Neuroscience
• Human-Computer Interaction
• Robotics

Background:

• Body representation defines self and interaction space.
• The rubber hand illusion demonstrates incorporating external objects into body representation via visuo-tactile stroking.
• This illusion causes illusory ownership and proprioceptive shifts.

Purpose of the Study:

• To investigate if visuo-motor congruency with a robotic hand can induce embodiment effects.
• To determine if synchronized movements, rather than visuo-tactile input, influence body representation.

Main Methods:

• Used a myoelectric-controlled robotic hand.
• Trained participants with synchronized visuo-motor movements between their own and the robot hand.
• Assessed changes in proprioceptive localization and sense of ownership.

Main Results:

• Synchronized real hand/robot hand movements caused a shift in proprioceptive hand localization toward the robot.
• No modulation of ownership sense was observed, regardless of movement synchrony.
• Visuo-motor synchrony influenced body part localization independently of somatosensory input.

Conclusions:

• Visuo-motor synchrony can alter body part localization in space.
• Proprioceptive shifts can occur without changes in body ownership.
• This suggests distinct neural mechanisms for body ownership and spatial representation.