Over the past several decades a large and impressive body of work from developmental neurobiology has provided a picture of mammalian brain development as the product of dynamic and adaptive processes operating within highly constrained, but constantly changing biological and environmental contexts. Data from both animal and human studies have fundamentally changed the way we think about development. The debate over the priority of nature or nurture is becoming outmoded as the evidence for the essential role of the interaction between biology and experience grows. Development reflects the gradual commitment of neural resources to stable functional systems, while retaining the capacity for adaptation to meet normally fluctuating environmental demands, or even extraordinary circumstances. The capacity for adaptive development continues through at least adolescence, and likely extends throughout the lifespan. The study of children with prenatal focal brain injury provides a model for articulating and specifying this dynamic view of development in humans. The children's injuries often affect substantial portions of one cerebral hemisphere, resulting in damage that would compromise cognitive ability in adults. However, longitudinal behavioral studies of this population have revealed only mild deficits. It is argued that the children's capacity for adaptation reflects normal developmental processes operating against a backdrop of serious neural perturbation. Four examples describing spatial cognitive development in this population of children provide evidence for adaptive change.
Keywords: prenatal lesions, focal brain injury, spatial cognition