Since the discovery of orientation columns by Hubel and Wiesel (1962) the modality of their development is controversial. Much debated is the question whether the circuit is heavily predetermined at birth or if it is largely shaped by visual experience. Nowadays one knows that at birth only a limited number of neurons of the primary visual cortex display any orientation selectivity and that this property develops gradually during the early post natal life. The authors wondered whether this limited set of genetically wired connections could serve as a scaffolding for the construction of the adult map. In other words: does an orientation selective neuron behave as a seed that spreads the organization of its receptive field to neighboring units? The authors developed a neural network and a learning algorithm based on a Hebbian model of synaptic potentiation to explore the development of orientation maps in the presence of a variable number of seeds. The authors found that the presence of pre-wired seeds has a powerful effect on the formation of a properly organized map of orientation selectivity.
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