We are so used to our senses that we do not actually think about how we use them and how complex the processes are that serve them. They mostly remain hidden within our brains. Senses and their nuances have captured the attention of scientists from a variety of disciplines for centuries. Psychologists, physicians, philosophers, and engineers are focusing their attention on our immanent companions: the senses.

In this book, the author guides the reader through an exciting exploration of the senses, illuminating the explanations with extensive details from anatomy, biology, physics, and mathematics.

The book is divided into 12 chapters. Chapter 1 describes the structure of the book and introduces some fundamental concepts that are used throughout. Chapter 2 is devoted to sensory systems and their relation to information processing, pattern recognition, and brain science. It also briefly introduces the connections between sensory systems, computer games, and virtual worlds.

Chapters 3 and 4 provide some mathematical concepts used here and there throughout the book. Chapter 3 introduces Fourier theory and chapter 4 is devoted to information theory. In my opinion, these two chapters are too technical for readers without previous knowledge; they do not succeed in explaining the concepts. Although it is clear that there is a fundamental relationship between Fourier and information theories and sensing, these two chapters contribute only collaterally to the book and could easily be skipped.

Chapter 5 is where the real meat about senses starts to appear. This chapter provides an excellent explanation of hearing. The author manages to interweave anatomy and engineering in a very appealing way. Chapter 6 explores the strategies of vision. In this chapter, the reader encounters the physical limitations of vision, the neural flows from the retina to the brain, and the role of photoreceptors, among other topics. The chapter ends with a brief overview of man-made visual devices. Chapter 7 elaborates on the correspondence problem. If you have ever wondered why vertebrates have two eyes and two ears instead of only one, this chapter provides clues to answer this question. Concepts like stereopsis and binaural hearing are properly explained and related to artificial systems with stereovision and 3D audio.

Chapter 8 explores the nuances of color and texture. In fact, most of the chapter is devoted to color; only a few pages elaborate on texture. The reader will be presented with surprising facts. For example, although humans have trichromatic vision (red, green, blue), some animals, like cats, seem to be colorblind, while others, such as turtles, possess tetrachromatic vision and may see ultraviolet light. The chapter includes some notes on artificial color and its relation to robotics and games.

Chemical senses are analyzed in chapter 9. We humans mainly use audiovisual information to guide our lives, but olfaction appears to play a key role in the way we unconsciously judge people. The secrets of olfaction and taste are revealed here, but be advised that chemical senses are yet to be fully understood and there is much research to do in this field. Chapter 10 considers the somatosensory system, which includes touch, thermal sensations, pain, and proprioceptive signals. As in the other chapters, the author concludes with some notes on artificial systems (in this case for touch). Chapter 11 elaborates on nonhuman sensory systems, including electrical sense, heat sense, magnetic sense, and navigation and sonar. The author briefly comments on how to enhance human senses with implants, and considers improvements to animats as well. Chapter 12 concludes the book with a discussion of sensory integration.

Reading this book gave me several hours of intellectual pleasure. Discovering the nuances of the senses is extremely exciting, and the author presents the concepts in a didactic manner that, most of the time, makes them appear natural to the reader. The distance between the fields of biology and engineering and computer science is generally regarded as great. However, after reading this book, it seems like the distance is quickly shrinking and the line that separates the fields is narrowing.

This book is intended for a wide audience, from nontechnical readers interested in the secrets of senses, to engineers and computer scientists with a keen interest in mimicking the sensing processes of humans and animals.