Synaptic rewiring for topographic mapping and receptive field development

✍ Scribed by Simeon A. Bamford; Alan F. Murray; David J. Willshaw

• Book ID: 104067254
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 770 KB
• Volume: 23
• Category: Article
• ISSN: 0893-6080
• DOI: 10.1016/j.neunet.2010.01.005

✦ Synopsis

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.