Longitudinal high-density EEG study of looming in full-term and preterm infants

Abstract

Electroencephalogram (EEG) was used on full-term and preterm infants at the age of 5 months and again at the age of 12 months to investigate brain electrical activity as a function of looming visual stimuli on a collision course. Analyses of visual evoked potential (VEP) were performed on EEG data recorded with a 128-channel sensor array. VEP results showed that prematurity affects the brain processing of looming visual stimuli under three different accelerations. Preterm infants at the age of 12 months respnded to the looming visual stimuli early in the looming sequence on average -1.12 s before virtual contact as compared to 12 month-old full term infants who responded on average -0.43 s before contact. In addition, full-term infants at the age of 12 months had switched to a strategy based on time, whereas preterm infants at the age of 12 months still appeared to be using a strategy based on visual angle. The results further showed that with growing age, both full-term abd preterm infants showed significantly shorter VEP durations for all three looming conditions compared to when they were 5 months old. However, full-term infants at the age of 12 months showed larger negative brain activity in the Pz electrode than at the age 5 months, but preterm infants did not show increased brain activity in the Pz electrode with age. Preterm infants showed poorer performance in looming visual stream which is specialized in processing visual motion. As the infants grow older they will face tasks with higher demands and complexity. The small deviations shown at an early age could possibly be a predictor of later visual processing disabilities.