A model of phototransduction by the human circadian system

The absolute and spectral sensitivities to light by the human cireadian system, measured through melatonin Suppression or phase shifting response, are beginning to emerge after a quarter century of active research. The present paper Outlines a hypothesized model of human circadian phototransduction that is consistent with the known neuroanatomy and physiology of the human Visual and circadian systems. Spectral opponency is fundamental to file model, providing a parsimonious explanation of some recently published data. The proposed model offers a framework for hypothesis testing and subsequent discussion Of file practical aspects of architectural lighting with respect to light and health. (c) 2005 Elsevier B.V. All rights reserved.