Neural plasticity and development in the first two years of life: Evidence from cognitive and socioemotional domains of research

Abstract Three models that can be used to investigate the effects of different environmental events on brain development and organization are explored. The insult model argues against brain plasticity, and the environmental model regards the brain as infinitely plastic. Our work is guided by the transactional model, which views brain development and organization as an interaction between (a) genetically coded programs for the formation and connectivity of brain structures and (b) environmental modifiers of these codes. Data are reported from our cognitive and socioemotional research studies that support the notion of plasticity during the first 2 years of life. From our work with normal developmental processes, we draw parallels to abnormal development and speculate how the transactional model can be used to explain abnormal brain organization and development.