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

Controversy exists regarding the influence of sleep state on the flash visu al evoked potential. This study recorded the visual evoked potential in a n ew-born infant in four different sleep states; wakefulness, drowsiness, act ive 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 t hat when this subject was awake the VEPs recorded differed substantially fr om those recorded when sleeping. Two of the four main components had shorte r peak latencies, one component was prolonged and one of the peak to trough amplitudes was consistently smaller when alert. This study highlights an i mportant and often overlooked aspect of developmental research that the sta te of the infant may affect developmental measures.