1. Synaptic rewiring for topographic mapping and receptive field development
- Author
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Bamford, Simeon A., Murray, Alan F., and Willshaw, David J.
- Subjects
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NEURAL transmission , *NEUROPLASTICITY , *MATHEMATICAL mappings , *SYNAPSES , *TOPOGRAPHIC maps , *SPATIAL variation , *ANALYSIS of variance , *COMPUTER networks , *MATHEMATICAL models - Abstract
Abstract: A model of topographic map refinement is presented which combines both weight plasticity and the formation and elimination of synapses, as well as both activity-dependent and activity-independent processes. The question of whether an activity-dependent process can refine a mapping created by an activity-independent process is addressed statistically. A new method of evaluating the quality of topographic projections is presented which allows independent consideration of the development of the centres and spatial variances of receptive fields for a projection. Synapse formation and elimination embed in the network topology changes in the weight distributions of synapses due to the activity-dependent learning rule used (spike-timing-dependent plasticity). In this model, the spatial variance of receptive fields can be reduced by an activity-dependent mechanism with or without spatially correlated inputs, but the accuracy of receptive field centres will not necessarily improve when synapses are formed based on distributions with on-average perfect topography. [Copyright &y& Elsevier]
- Published
- 2010
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