The three volume set LNCS 4232, LNCS 4233, and LNCS 4234 constitutes the refereed proceedings of the 13th International Conference on Neural Information Processing, ICONIP 2006, held in Hong Kong, China in October 2006. The 386 revised full papers presented were carefully reviewed and selected from 1175 submissions. The 126 papers of the first volume are organized in topical sections on neurobiological modeling and analysis, cognitive processing, mathematical modeling and analysis, learning algorithms, support vector machines, self-organizing maps, as well as independent component analysis and blind source separation. The second volume contains 128 contributions related to pattern classification, face analysis and processing, image processing, signal processing, computer vision, data pre-processing, forecasting and prediction, as well as neurodynamic and particle swarm optimization. The third volume offers 131 papers that deal with bioinformatics and biomedical applications, information security, data and text processing, financial applications, manufacturing systems, control and robotics, evolutionary algorithms and systems, fuzzy systems, and hardware implementations.