{'fraction_non_alphanumeric': 0.013959390862944163, 'fraction_numerical': 0.0, 'mean_word_length': 5.116279069767442, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Models for Pattern Formation in Development

We describe a number of general principles that underlie the formation of cortical maps such as occular dominance and orientation specificity. We show that most of the well-known mechanisms share certain generic properties. One question we address is what determines the periodicity of these maps. Models of Swindale and older models of Miller imposed the periodicity through cortical-cortical interactions. On the other hand the elastic map, the Kohonen model, and Dayan’s recent model all obtain the periodicity through an interaction of the cortical interactions and the input correlations. We show how and why these models differ and suggest some new models that operate on the same principles but do not require any imposed normalization.