Complexity Digest 2002.12 - 17

25-Mar-2002

Slow Feature Analysis: Unsupervised Learning of Invariances, Neural Comp Bookmark and Share

Abstract: Invariant features of temporally varying signals are useful for analysis and classification. Slow feature analysis (SFA) is a new method for learning invariant or slowly varying features from a vectorial input signal. It is based on a nonlinear expansion of the input signal and application of principal component analysis to this expanded signal and its time derivative. (...) SFA is applied first to complex cell tuning properties based on simple cell output, including disparity and motion. (...) The same unstructured network can learn translation, size, rotation, contrast, or, to a lesser degree, illumination invariance for one-dimensional objects, depending on only the training stimulus. Surprisingly, only a few training objects suffice to achieve good generalization to new objects. The generated representation is suitable for object recognition. Performance degrades if the network is trained to learn multiple invariances simultaneously.