| The purpose of this study was to investigate the sensitivity of experimental (event-related potentials and visual paired comparison) and clinical approaches to cognitive assessment in reflecting individual differences in biological and environmental experience in a longitudinal sample of infants of diabetic mothers (IDMs) and typically developing infants. In addition, this study examined the predictive validity of experimental measures of infant cognition to scores on tests of intellectual functioning in early childhood. Participants were typically developing infants and infants of diabetic mothers born between 37 and 42 weeks gestation. Infants were assessed as newborns by recording event-related potentials (ERPs) to familiar and novel auditory stimuli and at age 6 months by recording ERPs to familiar and novel visual stimuli and measuring preferential looking time in a visual paired comparison task. Participants completed standardized assessments using the Bayley Scales of Infant Development, Second Edition (BSID-II) at 12 and 34 months of age and the Wechsler Preschool and Primary Scale of Intelligence, Revised (WPPSI-R) at 48 months of age. Statistical analyses were conducted using independent samples t-tests and a series of hierarchical multiple regression analyses. IDMs did not significantly differ from controls on ERP or behavioral measures of cognitive functioning. Obstetric complications and macrosomia were related to amplitude of the ERP slow wave at age 6 months. Socioeconomic status predicted performance on the BSID-II and WPPSI-R at 30 and 48 months of age. Results from this study indicated that cognitive functioning in infants born to diabetic mothers was related to biological risk variables in the first year of life, but became more strongly related to environmental experiences after age 2 years. IDM group status, independent of the metabolic effects that can occur in the context of poor maternal glycemic control, did not significantly affect cognitive outcomes. Event-related potentials showed promise as a means of assessing infant cognition that was uniquely sensitive to early biological risk variables relative to the visual paired comparison and standard clinical assessments. Characteristics of ERP waveforms in the newborn period were found to be associated with the rate of change in cognitive development from infancy to early childhood. |
