Sensory Adaptation

Sensory adaptation is the reduction in a sensory receptor's responsiveness, and the resulting decline in a person's conscious awareness of a stimulus, following its constant or repeated presentation. It occurs at the level of the sense organs themselves, such as the eyes, ears, skin, and nose, rather than as a higher-level cognitive judgment, which is why a smell that is overpowering on entering a room fades from awareness within minutes even though the odor itself has not weakened. Because the nervous system is tuned to detect change, sensory adaptation lets attention shift toward new or changing stimuli rather than staying occupied by a constant background one.