Investigating developmental changes in susceptibility to temporal audiovisual illusions on balance and sensorimotor function in children.

Balance and movement rely on multisensory input. In older adults, audiovisual integration-measured via the Sound-Induced Flash Illusion (SIFI)-has been linked to balance and motor performance, suggesting that multisensory perceptual measures may relate to functional motor abilities. This study explored whether similar links exist in childhood or emerge later in development. A total of 118 children aged 4-17 years of age completed (1) a balance task (standing on one leg, eyes open vs. closed), (2) a timed visuomotor task (maximum target hits in 2 min), and (3) the SIFI task (judging flashes paired with beeps at varying stimulus onset asynchronies, SOAs). Older children used vision more for balance, showed better visuomotor performance, and were less susceptible to SIFI illusions at longer SOAs, indicating developmental refinement in audiovisual integration. However, we found no strong evidence linking SIFI performance with balance or motor performance. Exploratory analyses revealed that children with dance training and those who found the task easier were slightly less susceptible to the illusion. These results suggest that links between multisensory integration and sensorimotor performance may not be present in early childhood or may require more sensitive measures to detect, offering a potential avenue for future research.