adaptation level

n. A theoretical level of adaptation of a single dimension of a sensory system against which new levels of stimulation are judged. Thus a bucket of water isjudged as warm at 50 degrees Fahrenheit if a person has just removed his or her hand from a bucket of ice water. In this theory all dimensions of sensory perception have adaptation levels which change, resulting in differing perceptions of the same stimulus by the same person depending on the immediately preceding experience.