The development of the bodily self: Children’s responses to the Rubber Hand Illusion

Abstract

The bodily self is constructed from multisensory information. However, little is known of the relationship between multisensory development and the emerging sense of self. We investigated how multisensory processes underpin the developing sense of bodily self by measuring the strength of the ‘Rubber Hand Illusion’ in young children (4 to 9 years old) and adults. Stroking mode (synchronous vs asynchronous) was varied between subjects. Following this visuotactile stimulation, we measured processes of body localisation using intermanual pointing, and feelings of body ownership using questionnaire responses. Intermanual pointing showed that children were as sensitive as adults to visual-tactile synchrony cues for hand position. Similarly, explicit feelings of embodiment, measured by questionnaire items, were sensitive to visual-tactile integration independent of age. These converging results indicate a visual-tactile pathway to the bodily self which matures by at least 4 years of age. However, regardless of synchrony cues, children’s pointing was more captured by the fake hand than adults, indicating a second, later-maturing process based on visual-proprioceptive information. These findings demonstrate two dissociable processes underlying body representation in early life: an early-maturing visual tactile process controlling hand localisation and ownership, and a later-developing visual-proprioceptive process controlling localisation only. The findings further suggest that hand localisation and ownership may not always be so intimately bound together as adult data would suggest, and therefore call for a reassessment of the systems involved in adult own-body perception.