Fechner made conscious perception measurable and founded experimental psychology

Evidence

One of Weber’s students, Gustav Fechner (1801–1887), formalized Weber’s work with mathematics. He noted, in particular, that there was a way to measure the magnitude of sensation. Fechner’s work was revolutionary: his claim was that the conscious perception of a stimulus is related to size of the stimulus in the physical world and that perception and physical stimuli are, in some sense, interchangeable. This idea formed the foundation for all modern psychophysics and opened the door to the measurement of perception. Fechner coined the term “psychophysics” and published his experiments on sensory measurements in his 1860 book Elements of Psycho­physics, where he described psychophysical methods and psychophysical relationships. His book marked the beginning of experimental psychology because it brought sensation and perception, otherwise thought to be unmeasurable, under the requirements of measurement. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 60

Categorization

• DEFINE: Defines psychophysics, its founding premise that perception and stimulus magnitudes are interchangeable, and the 1860 origin text.
• XREF: Fechner’s interchangeability thesis underlies the Stevens Power Law and measurement debates familiar from psychophysics literature.