Visualization of Learning in Multi-layer Perceptron Networks using PCA

This article is concerned with the use of scientific visualization methods for the analysis of feedforward neural networks. Inevitably, the kinds of data associated with the design and implementation of neural networks are of very high dimensionality, presenting a major challenge for visualization. A method is described using the well-known statistical technique of Principal Component Analysis. This is found to be an effective and useful method of visualizing the learning trajectories of many learning algorithms such as backpropagation, and can also be used to provide insight into the learning process and the nature of the error surface. Keywords—Visualization, Multi-layer Perceptron, Error Surface, Artificial Neural Network, Principal Component Analysis.