The development of a flexible bodily representation: behavioural outcomes and brain oscillatory activity during the Rubber Hand Illusion in preterm and full-term school-age children

During childhood, the body undergoes rapid changes suggesting the need to constantlyupdate body representation based on the integration of multisensory signals. Sensoryexperiences in critical periods of early development may have a significant impact onthe neurobiological mechanisms underpinning the development of the sense of one’sown body. Specifically, preterm children are at risk for sensory processing difficulties,which may lead to specific vulnerability in binding together sensory information in orderto modulate the representation of the bodily self. The present study aims to investigatethe malleability of body ownership in preterm (N= 21) and full-term (N= 19) school-agechildren, as reflected by sensitivity to the Rubber Hand Illusion. The results revealedthat multisensory processes underlying the ability to identify a rubber hand as beingpart of one’s own body are already established in childhood, as indicated by a highersubjective feeling of embodiment over the rubber hand during synchronous visual-tactilestimulation. Notably, the effect of visual-tactile synchrony was related to the suppressionof the alpha band oscillations over frontal, central, and parietal scalp regions, possiblyindicating a greater activation of somatosensory and associative areas underpinning theillusory body ownership. Moreover, an interaction effect between visual-tactile conditionand group emerged, suggesting that preterm children showed a greater suppressionof alpha oscillatory activity during the illusion. This result together with lower scoresof subjective embodiment over the rubber hand reported by preterm children indicatethat preterm birth may affect the development of the flexible representation of the body.These findings provide an essential contribution to better understand the processesof identification and differentiation of the bodily self from the external environment, inboth full-term and preterm children, paving the way for a multisensory and embodiedapproach to the investigation of social and cognitive development.