stimulus magnitude

psychology

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July 14, 2026

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Psychophysics is the study of the relationship between psychological experiences and physical stimuli. It seeks to understand how we perceive the world by measuring the quantitative relationship between sensations and the stimuli that cause them.1

A key concept is the stimulus magnitude, which refers to the intensity of a physical stimulus. Psychophysics investigates the absolute stimulus threshold, the minimum stimulus magnitude needed to produce a sensation. It also explores Weber's law, which states that the change in stimulus magnitude required to produce a just-noticeable difference in sensation is proportional to the original stimulus magnitude. This field, established by Gustav Theodor Fechner, uses scientific methods to quantify sensory experiences.1

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Gustav Fechner
…in relation to the physical magnitude of stimuli. Most important, he devised an equation to express the theory of the just-noticeable difference, advanced earlier by Ernst Heinrich Weber. This theory concerns the sensory ability to discriminate when two stimuli (e.g., two weights) are just noticeably different from each other. Later…
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…in relation to the physical magnitude of stimuli. Most important, he devised an equation to express the theory of the just-noticeable difference, advanced earlier by Ernst Heinrich Weber. This theory concerns the sensory ability to discriminate when two stimuli (e.g., two weights) are just noticeably different from each other. Later…
Read More

psychophysics
By determining the stimulus magnitude that is just sufficient to produce a sensation (or a response), it is possible to specify the minimum perceptible stimulus, or the absolute stimulus threshold (stimulus limen), for the various senses. The central inquiry of psychophysics pertains to the search for a lawful,…
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By determining the stimulus magnitude that is just sufficient to produce a sensation (or a response), it is possible to specify the minimum perceptible stimulus, or the absolute stimulus threshold (stimulus limen), for the various senses. The central inquiry of psychophysics pertains to the search for a lawful,…
Read More