Rubber hand illusions and size-weight illusions: self-representation modulates representation of external objects

Area of Science:

• Neuroscience
• Cognitive Psychology
• Perception

Background:

• Bodily illusions provide insights into the sense of self and body ownership.
• The rubber hand illusion (RHI) is a key paradigm for studying body representation.
• Understanding how self-representation influences perception is crucial for cognitive science.

Purpose of the Study:

• To investigate if body representation calibrates the perception of external objects.
• To explore the influence of the rubber hand illusion on exteroceptive perception.
• To determine the role of self-representation in object perception.

Main Methods:

• Participants experienced the rubber hand illusion (RHI) with varying glove sizes (large or small).
• Simultaneous stimulation of the participant's own hand and a rubber hand was applied.
• Participants grasped cylinders of identical size but varying weight after the RHI manipulation.

Main Results:

• The RHI, particularly with a larger glove, led to cylinders feeling heavier.
• An illusory increase in perceived hand size altered the perception of object weight.
• Self-representation was shown to directly influence exteroceptive judgments.

Conclusions:

• The sense of one's own body acts as a fundamental reference frame for general perception.
• Body representation dynamically calibrates how we perceive external object properties.
• Illusory changes in body size can induce perceptual distortions in other modalities, like weight perception.