Event-related potentials and information processing in infants with and without Down syndrome.

Event-related brain potentials (ERPs) were recorded from 6-month-old infants with and without Down syndrome presented with a visual recognition memory task. The ERP morphology was the same for both groups. The chronometry of information processing by infants with Down syndrome was 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 opposed to more posterior processes. Infants with Down syndrome had an amplitude decrement in Nc over the central but not frontal cortex. The infants with Down syndrome also had similar visual fixation. Infants may have more subtle differences than those found in older individuals with Down syndrome.