Biology Reference
In-Depth Information
Three different contributory factors were mentioned: (1) the 'dark
light' of rods was generally much lower than that of cones, (2) rods
had a much greater spatial and temporal summation capability due to
the properties of neural connections between receptors and ganglion
cells (by improving the conditions for spatial and temporal summation
maximally, the relative sensitivity difference between rods and cones
may increase by more than 1 log unit), and (3) the rhodopsin of rods
had a greater total optical density than the cone photopigments. The
latter factor, however, was assumed to play only a minor role.
