The developmental pattern of concurrent synaptogenesis in rhesus monkeys is consistent with a straightforward model of relations between brain and cognitive development. Concurrent synaptogenesis is hypothesized to lay the primary cortical foundation for a series of developmental levels in middle infancy that have been empirically documented in…

The study compared play among five groups of children (ages 3-7 years): normal children (N=41); those diagnosed with language delays (N=241), those with autism but normal intelligence (N=71), those with autism and mental retardation (N=97), and those with nonautistic mental deficiency (N=86). Each child was evaluated using a 25 minute structured…

Down Syndrome children (N=229), aged 1-83 months, from Australia, Canada, and Germany were tested using the Bayley Scales of Infant Development. Test performances on the Bayley's Mental and Motor scales were not dissimilar, leading to the conclusion that young Down Syndrome children from different countries with relatively comparable standards of…