## Introduction

The appendix consists of five sections. In Appendix section 1 I review several properties of shift-invariant linear systems and outline proofs of these properties. This appendix also includes a brief discussion of the Discrete Fourier Series, a method for representing functions as the weighted sum of harmonic functions. Appendix section 2 contains a review of the main aspects of visual display calibration for psychophysical experiments. Appendix section 3 contains a description of the basic results in classification theory, Bayes Rule and linear discriminant functions. Appendix section 4 provides a geometric interpretation of vector and matrix multiplication as well as a brief introduction to signal estimation. Appendix section 5 outlines how to compute a motion flow field that arises when an observer moves through a fixed environment.