EVENT-RELATED POTENTIALS AND INFORMATION-PROCESSING IN INFANTS WITH AND WITHOUT DOWN-SYNDROME

Event-related brain potentials (ERPs) were recorded from 6-month-old i nfants with and without Down syndrome presented with a visual recognit ion memory task. The ERP morphology was the same for both groups. The chronometry of information processing by infants with Down syndrome wa s similar to or faster than that of the infants without Down syndrome, depending on ERP component. The amplitude differences between groups may implicate frontal attentional processes in Down syndrome as oppose d to more posterior processes. Infants with Down syndrome had an ampli tude decrement in Nc over the central but not frontal cortex. The infa nts with Down syndrome also had similar visual fixation. Infants may h ave more subtle differences than those found in older individuals with Down syndrome.