Abstract
The purpose of this study is to investigate how we perceive temporal changes of illuminance when the illuminance is changed at a very slow rate. Subjects observed a test box in which the illuminance was gradually changed. Their task was to notified the experimenter as soon as they perceived the changes in illuminance of the test box. The results indicated that perception of the illuminance change was determined by the ratio of an increment or decrement of the detection illuminance and initial illuminance. It was also implied that a short- and/or long-term memory of brightness might influence the perception of illuminance changes.
