DEVELOPMENT AND PLASTICITY IN THE BRAIN

Abstract

This paper examines different aspects of the development of the brain before birth, and the subsequent plasticity after birth. First, rough outlines of the pre-natal formation of the neural structures are presented: cell identity, neuron migration, axon formation and initial synapse formation. Second, the paper looks at the post-natal plasticity with regard to critical periods. A short introduction to the visual system serves as a starting point for a description of Hubel and Wiesel’s pioneering experiments on cats and monkeys. In addition, Harlow’s experiments with sensory deprivation of monkeys are described. This leads to an attempt to link these results to a computational strategy for the analysis and representation of the connections between sensory input and motor output: feed-forward neural units that are dynamically re-grouped by reciprocal connections. The conclusion attempts to place development and plasticity in a broader context within the brain.