Roughness perception during the rubber hand illusion

Area of Science:

• Neuroscience
• Psychology
• Somatosensation

Background:

• The rubber hand illusion (RHI) demonstrates multisensory integration, where visual and tactile inputs create a sense of body ownership.
• Previous research suggests cognitive factors may modulate the RHI, beyond simple bottom-up sensory processing.

Purpose of the Study:

• To investigate if the conceptual interpretation of tactile stimuli (roughness) influences the RHI.
• To determine if the RHI affects the perceived sensory quality (roughness) of tactile stimuli.

Main Methods:

• Utilized a classical RHI paradigm with visual stroking of a rubber hand using soft or rough fabric.
• Participants received synchronous or asynchronous tactile stimulation, congruent or incongruent with the visual stimulus.
• Assessed both implicit and explicit measures of the RHI and perceived tactile quality.

Main Results:

• Congruence or incongruence between visual and tactile stimulation did not impact the RHI on implicit or explicit levels.
• Experiencing the RHI did not modulate the perceived sensory quality of tactile stimulation on the participant's own hand.

Conclusions:

• The RHI appears resistant to top-down cognitive influences, such as conceptual interpretations of tactile sensations.
• Findings challenge the notion that the participant's own hand disappears and is actively replaced by the rubber hand during the RHI.