During the first 24 months of the project, we have focused on tracing the developmental origins of bodily self-representation (BSR), from the prenatal stage through early infancy, and on identifying how atypical motor experience may alter this trajectory. Our approach combines behavioral and neurophysiological methods, applied across typical and clinical populations, to characterize when and how key components of BSR emerge and are supported by developing neural systems.
In the prenatal phase, we refined a novel method to track fetal eye-lens movement as an index of attentional orienting across sensory modalities. Our findings demonstrate that fetuses respond to visual, acoustic and tactile stimuli already at the beginning of the third trimester. For the multisensory stimulation protocol, data collection is now nearly complete and will allow us to assess, for the first time, the presence or absence of multisensory integration (MSI) in utero.
Postnatally, we conducted EEG studies in neonates and infants, focusing on both visual and multisensory paradigms. Using a fast periodic visual stimulation (FPVS) protocol, we found that 6 months old infants are able to visually discriminate images of body parts from objects, and this discrimination is associated with emerging fine motor abilities. These results suggest a functional link between motor development and the formation of visual body representations early in life. For what concerns multisensory integration paradigms, we developed an ERP protocol capable of capturing multisensory integration modulations induced by postural manipulations that ecologically mimic the motor milestones achieved by infants at different ages. Furthermore, we developed a new methodology for extracting kinematic parameters that describe infants' motor abilities at the various timepoints at which they were tested with the EEG protocol.
To validate and optimize the experimental paradigms for developmental neuroimaging, we piloted them in adults using fMRI and fNIRS. In an fMRI study targeting visual body perception, we employed inter-subject correlation analyses to identify common patterns of brain activity across participants. Results indicated increased engagement of somatosensory regions when participants viewed images of their own hand, suggesting early involvement of cross-modal networks in bodily self-processing. Then, we piloted an fMRI audio-tactile multisensory task designed to reveal the recruitment of the functional network involved in body-related multisensory integration without requiring active involvement of the participant. We revealed activation of the bodily-self representation network during a post-MSI training resting state, making it suitable for pre- and postnatal populations. A significant methodological advancement was the collaboration with the University of Tübingen (Prof. Preissl) to integrate fetal MEG into the project.
Finally, we initiated data collection in clinical populations to examine how early motor deprivation influences BSR development. We used the same experimental protocols as in the typical cohorts to assess both children with congenital motor impairments (e.g. cerebral palsy) and individuals with acquired motor deficits (e.g. post-stroke hemiplegia). Preliminary findings indicate that disrupted motor experience affects the emergence and integration of bodily self-related signals.
