'… the book is a comprehensive account of research and current thinking regarding the possibility of human tetrachromacy. By bringing together the literature in this way, the authors make a compelling case for a change in thinking and push the field to expand on the standard trichromatic model of human colour perception.' Stacey Aston, Elements in Perception

• 1. Introduction and Scope; 2. Investigating color perception in individuals with normal photopigment variations; 3. An Empirical Investigation of Tetrachromacy; 4. Summary and Discussion; 5. Conclusions

'… the book is a comprehensive account of research and current thinking regarding the possibility of human tetrachromacy. By bringing together the literature in this way, the authors make a compelling case for a change in thinking and push the field to expand on the standard trichromatic model of human colour perception.' Stacey Aston, Elements in Perception

• 1. Introduction and Scope; 2. Investigating color perception in individuals with normal photopigment variations; 3. An Empirical Investigation of Tetrachromacy; 4. Summary and Discussion; 5. Conclusions

'… the book is a comprehensive account of research and current thinking regarding the possibility of human tetrachromacy. By bringing together the literature in this way, the authors make a compelling case for a change in thinking and push the field to expand on the standard trichromatic model of human colour perception.' Stacey Aston, Elements in Perception

• 1. Introduction and Scope; 2. Investigating color perception in individuals with normal photopigment variations; 3. An Empirical Investigation of Tetrachromacy; 4. Summary and Discussion; 5. Conclusions