This project will study the development of brain-behavior organization and information processing in high-risk premature infants with birth weights less than 1200g and who have survived perinatal intracranial hemorrhage (ICH) and periventricular leukomalacia (PVL). A prospective short-term longitudinal design (study 1) will be used to investigate the developmental sequence of the late endogenous event-related potentials (ERP) of the brain and behavioral performance in visual information processing tasks during the first two years. Four groups of preterm infants will be followed for two years: (1) a group with persistent ventriculomegaly; (2) a group with periventricular morphological abnormalities (PVL) beyond the expected date of term birth; (3) a group of ICH preterm infants whose ventricular abnormalities are resolved by the expected data of term birth (ICH without ventriculomegaly); and (4) a group of non-ICH preterm controls. These infants have been assessed by a battery of radiographic and standardized developmental exams in a currently ongoing follow- up program of premature infants with less than 1200 g birth weights. Infants in each of the groups will receive repeated assessments with an ERP-behavioral protocol at corrected ages 1, 3, 6, 12, 18, and 24 months. The project brings together in a unique collaboration the study of both cognitive-related ERPs as functional neuro-behavioral assessment measures and an extensive on-going followup program utilizing serial ultrasonographic description of each infant's brain status.