Experience-Dependent Plasticity

Experience-dependent plasticity refers to changes in the anatomical or functional organization of the nervous system as a consequence of sensory input or motor output. This can be at the anatomical level of how different neurons project from one area to the next (e.g., how neurons from the eye [Page 408]send their axons to the brain). Alternatively, the gross anatomical projections themselves may not change; rather, the individual synapses are refined, or pruned, so that only restricted recipient neurons are contacted. Finally, there can be instances where functional changes occur in the absence of anatomical changes. In this case, certain synapses are strengthened, whereas other synapses are weakened, with the result that neurons that used to respond to a particular sensory input now respond to a ...