| dc.description.abstract | High-density electroencephalogram (EEG) was utilized longitudinally to study brain electrical activity in 10 full-term and 10 preterm participants at 4 months, 12 months, and 6 years of age, by investigating visual motion perception responses to structured optic flow and random visual motion. Analyses of visual evoked potentials (VEPs), temporal spectral evolution (TSE), and coherence connectivity were performed on EEG data recorded with 128/256-channel arrays. VEP results revealed significant improvements in full-term infants’ latencies at 12 months for forwards and reversed optic flow, and at 6 years for random visual motion. Preterm infants did not show increased sensitivity to visual motion during the first year of life. However, at 6 years of age, preterm children reduced their N2 latencies to the level of the full-term children. At 12 months, full-term infants differentiated between visual motion conditions, with increased latencies observed from forwards optic flow to reversed optic flow and the longest latencies displayed for random visual motion. Preterm participants, on the other hand, did not demonstrate improved differentiation between visual motion conditions at either 12 months or 6 years of age. Analysis of N2 peak amplitudes exhibited significantly higher values in response to structured optic flow compared to random visual motion for both full-term and preterm participants at all ages. Moreover, a significant age-related decline in amplitudes for visual motion was observed between 12 months and 6 years for both full-term and preterm participants. Differences in induced activities were noted in comparisons between TSEs of visual motion and static control condition, revealing desynchronized activities predominantly in the theta-band range for infants at 4 months, transitioning to the theta-alpha band range when they were 12 months, and further extending into the alpha and beta ranges when they were tested at 6 years of age. Synchronized alpha-beta band activities were observed only in full-term infants at 12 months, while synchronizations at higher frequencies were noted in the beta and early gamma band ranges in 6-year-olds, especially in full-term children. Coherence connectivity analysis demonstrated greater functional connectivity within occipital and parietal areas in full-term participants compared to their preterm peers when comparing visual motion to static control condition. Specifically, only full-term children at 6 years of age displayed interactions with the PM source. Overall, divergent developmental trajectories were evident between full-term and preterm individuals from infancy to early childhood. Progression in visual motion perception for full-term participants during the first year of life to school age can be attributed to neural maturation and the formation of specialized networks. In contrast, the observed neurodevelopmental delay in preterm infants that persisted into school age was potentially linked to their premature birth resulting in an impaired dorsal visual processing stream. | |
