Predictor for closed-loop Brain Computer Interface to facilitate perceptual learning in infants: A preliminary investigation

Background: With age, full-term infants develop efficient perceptual systems. However, due to insufficient neuronal development it is compromised in preterm newborns, putting them at risk for perceptual deficiencies. This study used high-density EEG for longitudinally investigating EEG power associated with the visual evoked potential as a function of visual looming motion in full-term and preterm infants. Methods: A total of 16 healthy infants, 8 full term and 8 preterm infants were recruited for this study and were tested twice, session 1 at 4-5 months, followed by session 2 at 11-12 months. The preterm infants were born at ≤ 33 weeks of gestation and tested corrected for prematurity. Encephalogram was recorded at 500 Hz with a 128-channel array while infants watched a looming ball approach them on a collision course under three different accelerations. Looming- related VEP responses registered during the final 1.5 s before the virtual collision at occipital electrodes (60-100) were considered for the three loom speeds, and average EEG power for theta, alpha and beta frequencies were computed. Results: Neural oscillations in the theta band were prominent in both full-term and preterm infants for both sessions. However mean EEG power in theta was more prominent for full-term than for preterm infants for both sessions. Longitudinal investigation showed that the mean energy for preterms in session 1 and 2 remained the same which might indicate slow development in premature infants. A significant two-way interaction of Frequency band × Group was found, F(2,28)=6.892, p=0.04, showing that full-term infants displayed higher EEG power compared to premature infants at both sessions, but only in the theta-band and not in the alpha and beta bands. Conclusion: Preliminary findings show that the average EEG power in the theta band can be used as one of several potential demarcators to distinguish between mature and immature brain responses to visual looming. Further research is needed to establish an acceptable theta power range during the first year of life, as an indicator of mature brain responses to looming stimuli.