Effect of sleep state on the flash visual evoked potential. A case study.

Controversy exists regarding the influence of sleep state on the flash visual evoked potential. This study recorded the visual evoked potential in a new-born infant in four different sleep states; wakefulness. drowsiness, active sleep and quiet sleep over a five hour period. The infant's heart rate, breathing rate and breathing regularity were also recorded. It was clear that when this subject was awake the VEPs recorded differed substantially from those recorded when sleeping. Two of the four main components had shorter peak latencies, one component was prolonged and one of the peak to trough amplitudes was consistently smaller when alert. This study highlights an important and often overlooked aspect of developmental research that the state of the infant may affect developmental measures.