Critical Periods in Brain Development

Neuronal circuits are shaped by experience during 'critical periods' of early postnatal life. The ability to control the timing, duration, and closure of these heightened levels of brain plasticity has recently become experimentally accessible, especially in the developing visual system. This book summarizes for the first time our current neurobiological understanding of how critical periods work across several systems and species, including humans. It delineates a number of emerging fundamental principles: functional competition between inputs, role for neural activity, structural consolidation, regulation by experience (not simply age), special role for inhibition in the CNS, potent influence of attention and motivation, unique timing and duration as well as use of distinct molecular mechanisms across brain regions, and the potential for reactivation in adulthood. It is a timely piece, as the experimental data have mostly become available within the past five years while social demand to apply this information to human learning has risen dramatically.A deeper understanding of critical periods opens new avenues to "nurture the brain" - from nascent international efforts to link brain science and education to improving recovery from injury in adults, devising new strategies for therapy and for life-long learning.