Development of visual evoked potentials and photic driving responses in normal full term, low risk premature, and Trisomy-21 infants during the first year of life.

Stroboscopic visual evoked potentials (SVEPs) and photic driving responses were recorded during the first week of life post term and at 4, 13, 26 and 52 weeks in normal full term, low risk premature, and Trisomy-21 infants. The age effect on SVEP P2 peak latency was significant (P less than 0.001). P2 latency for the Trisomy-21 group was significantly prolonged at 1 week of age only. Voltages and interhemispheric symmetry were highly variable, with no significant age or group effects. There is considerable variability in photic driving effects, even within sessions. Maximal driving frequencies are difficult to determine; they may be near 15 Hz at term. The age effect on optimal driving frequency (3-4 Hz at week 1 increasing to 5 Hz at 12 months) was significant (P less than 0.001). The between-groups effect was not significant. The results are discussed in terms of (1) our own previous results, (2) previous results reported in the literature, and (3) significance in clinical applications.