Maturation of blink reflex in children.

The blink reflex was examined in 57 subjects aged from neonate to adult in the alert state. The ipsilateral late response (R2) was elicited in all subjects and considered most suitable to evaluate maturational changes of the blink reflex. In a few subjects older than 3 years and of adults, the ipsilateral early response (R1) was difficult to observe. The contralateral late response (R2') could not be obtained in 32% of neonates and infants. From the observation about developmental change of an interference pattern, a latency shortening of R2 and a latency difference between R2' and R2, the blink reflex in children may be considered as mature at no later than 5 years of age. In addition, the R2 latency tended to increase temporarily through 1 or 2 years from late infancy. The reflex circuit evaluated by the blink reflex in children may partially change its makeup after the early infantile period and is almost fully mature at no later than 5 years.