Just-noticeable difference

The just-noticeable difference (JND), also known as the difference threshold or the minimal detectable difference, refers to the smallest change in a stimulus that can be detected by a sensory system. It represents the minimum amount of change that a person can perceive between two stimuli. The concept of JND is rooted in psychophysics, a field of study that examines the relationship between physical stimuli and the sensations and perceptions they produce.