BN Seminar - Phil Nelson (Upenn): 'Old and new news about single-photon sensitivity in human vision'



16:00 hrs


One often hears that human vision is “sensitive to single photons,” but in fact the faintest flash of light that can reliably be reported by human subjects is closer to 100 photons. Nevertheless, there is a sense in which the familiar claim is true. Experiments conducted long after the seminal work of de Vries, Hecht, Shlaer, and Pirenne now admit a more precise, and in some ways even more remarkable, conclusion to be drawn about our visual apparatus. A simple model that incorporates both old news (response of single rod cells) and newer news (loss at the first synapse) can account in detail for both old and new psychophysical data.