Psychophysics is the primary scientific tool for understanding how the physical world of colors, sounds, odors, movements and shapes translates into the sensory world of sight, hearing, touch, taste and smell - in other words, how matter translates into mind. This book is the first to combine into a single volume the principles underlying the science of psychophysical measurement and the practical tools necessary to analyze data from psychophysical experiments. Written in a style that makes even the trickiest concepts and procedures accessible to the non-expert, this book is essential reading.