selection-time

from The Century Dictionary.

• noun In psychophysics: The duration of the selective reaction (discriminative or cognitive type).
• noun The duration of the selective reaction, minus the duration of the discriminative or cognitive reaction.
• noun where R is the reflecting power, k the coefficient of absorption, and n the index of refraction. In the case of metals, for example, which are nearly opaque, k has large values, and n(1 + k) is very large compared with 2n, so that R is almost equal to unity. The reflecting power of such substances is therefore very large compared with that of transparent media. Since k, where selective absorption occurs, may vary greatly for different colors, the reflected light from the surface of many metals, such as copper, is strongly colored. The dependence of the index of refraction, n, upon the value of k explains the anomalous dispersion of substances having strong absorption-bands. See anomalous dispersion.