 Researchers excluded a number of items that implicated language, motor, attentional and social functioning from the original measures the modified form was administered to 17 infants with Down syndrome and to 41 typically developing infants.Results suggested the modified version provided a meaningful and stable measure of cognitive functioning in infants with Down syndrome.Researchers assessed the predictive validity of the BSID-II Mental Development Index (MDI) for cognitive function at school age for infants born with extremely low birth weight (ELBW).