Longitudinal neural development of looming visual motion processing in full-term and premature infants and children

This longitudinal study investigated electrical brain responses to approaching visual motion in full-term and preterm infants and children at 4 months, 1 year, and 6 years. Participants viewed a virtual ball approaching head-on at fast, medium, and slow speeds. Full-term participants showed looming-related brain responses that occurred progressively closer to the point of virtual collision, with mean time-to-collision (TTC) values decreasing from -835 ms at 4 months to -575 ms at 1 year and -260 ms at 6 years. In contrast, preterm children exhibited only modest improvement between 1 year (-850 ms) and 6 years (-435 ms). At both 1 and 6 years, full-term children showed their responses at consistent TTC values across loom speeds, significantly nearer to collision than their preterm peers, who relied on a less efficient strategy based on loom visual angle during infancy. By 6 years, preterm children had also adopted a time-based strategy, yet their responses still occurred significantly earlier in the looming sequence than those of full-term children. Time-frequency analysis (Temporal Spectral Evolution, TSE) revealed synchronised gamma and desynchronised theta, alpha, and beta activity in response to looming motion in both groups during infancy. With age, full-term children showed stronger and more frequency-specific oscillatory activity than preterm children. Coherence connectivity analysis further demonstrated more extensive and organized functional connections in full-term participants at all ages. Together, these findings indicate persistent cortical immaturity and reduced dorsal-stream integrity in children born preterm, contributing to deficits in visual motion perception that extend from infancy into early childhood.