Discrimination between real-time and delayed visual feedback of self-performed leg movements in the first year of life

The current study investigated the role of timing on infant self-perception. We tested whether 3-, 6- and 9-month-olds are able to discriminate between real-time and delayed visual feedback of their leg movements. Infants watched their legs simultaneously on two monitors. Initially both monitors presented their legs in real time. After 60 seconds one monitor switched to the presentation of visual feedback delayed by 3 seconds. Preferential looking was coded. Three-month-olds looked equally long at both displays. Although, the 6-month-olds tended to look longer at the delayed presentation, only the 9-month-old infants significantly preferred the delayed video display, indicating that they detected the difference in the timing of the feedback. This finding suggests that the use of timing in self-perception becomes increasingly robust by the end of the first year of life