FECHNER’S LAW

Fechner’s Law: Definition, History, and Characteristics

Fechner’s Law is a psychophysical law that states that the magnitude of a physical stimulus is proportional to the logarithm of its intensity. This law was first formulated by the German psychologist and physicist Gustav Fechner in 1860 and is also known as the Weber-Fechner law. Fechner’s law is important for understanding the relationship between physical stimuli and psychological perception.

Definition

Fechner’s Law states that the magnitude of a physical stimulus is proportional to the logarithm of its intensity. This means that for a given physical stimulus, the amount of perceived psychological response increases by a constant factor with each increase in the intensity of the stimulus. For example, if the intensity of a sound is doubled, the amount of perceived psychological response will increase by a constant amount regardless of the original intensity. This law applies to most forms of physical stimuli such as light, sound, taste, and smell.

History

Gustav Fechner was a German psychologist and physicist who first formulated the concept of Fechner’s Law in 1860. Fechner was researching the relationship between physical stimuli and psychological perception and discovered that the magnitude of a physical stimulus is proportional to the logarithm of its intensity. This discovery was based on the observation that the human perception of a physical stimulus does not increase linearly with its intensity.

Characteristics

Fechner’s Law is an important concept in psychophysics, which is the study of the relationship between physical stimuli and psychological perception. This law states that the magnitude of a physical stimulus is proportional to the logarithm of its intensity. This means that for a given physical stimulus, the amount of perceived psychological response increases by a constant factor with each increase in the intensity of the stimulus. This law is also known as the Weber-Fechner law.

References

Fechner, G. (1860). Elemente der Psychophysik. Leipzig: Breitkopf und Härtel.

Hecht, S., & Hakim, M. (1932). The Fechner Law. American Journal of Psychology, 44(3), 418-444.

Krantz, D. H., & Luce, R. D. (1971). Fechner’s Law and Weber’s Law. In R. D. Luce, R. R. Bush, & E. Galanter (Eds.), Handbook of Mathematical Psychology (Vol. 2, pp. 449-506). New York: Wiley.

Robb, R. A. (1994). Fechner’s Law and the Weber-Fechner Law. In K. B. Madsen (Ed.), Handbook of Perception and Cognition (Vol. 8, pp. 1-60). San Diego, CA: Academic Press.

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