The duplicity theory of vision: from Newton to the present

The duplicity theory of vision concerns the comparisons (both differences and similarities) and interaction between the cone and rod systems in the visual pathways, with the assumption that the cone system is active during daylight vision and the rod system functions in low light (night time). Research on this aspect of vision dates back to the 17th century and the work of Newton, and is still ongoing today. This book describes the origin and development of this fundamental theory within vision research - whilst also examining the Young-Helmholtz trichromatic colour theory, and the opponent colour theory of Hering - and presents evidence and ideas in light of modern conceptions of the theory. Written for academic researchers and graduate students, the book brings back knowledge of the tradition of duplicity theory, inspiring questions related to anatomy, comparative biology, molecular biology, photochemistry, physiology, genetics, phylogenetics and psychophysics. Development of the basic ideas of the duplicity theory from Newton to G.E. Müller Newton tradition Schultze tradition Goethe tradition: the phenomenological approach Colour theories of Armin Tschermak Development of the duplicity theory from 1930-1966 Duplicity theory of Polyak Investigations of H.K. Hartline and S.W. Kuffler Duplicity theory of R. Granit Contributions of E.N. Willmer, P. Saugstad & A. Saugstad, and I. Lie Status of the duplicity theory in the mid 1960s and its further development Chromatic rod vision: a historical account - Night vision may appear bluish Mechanisms of chromatic rod vision in scotopic illumination Rod-cone interactions in mesopic vision Further exploration of chromatic rod vision Theories of sensitivity regulation of the rod and cone systems: a historical account Early photochemical explanations Contribution of S. Hecht Contribution of G. Wald: photochemical sensitivity Relationship between amount of rhodopsin and sensitivity during dark adaptation Post-receptor sensitivity regulation mechanisms Rushton's AGC model Contribution of H.B. Barlow Rushton and Barlow compared Dowling-Rushton equation refuted Several mechanisms involved in sensitivity regulation Sensitivity regulation due to rod-cone interaction Modern conceptions of sensitivity regulation Factors that triggered the paradigm shifts in the development of the duplicity theory Summary of K.R. Popper's and T.S. Kuhn's models of scientific development Development of the duplicity theory as a test of Popper's and Kuhn's models. This book describes the origin and development of the duplicity theory of vision - whilst also examining the Young-Helmholtz trichromatic colour theory, and the opponent colour theory of Hering - discussing the significance and implications of these findings and presenting evidence and ideas in light of modern conceptions of the theory.