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The Psychophysical Law

Building upon the classical works of Weber and Fechner in the last century about relative perceptual thresholds, which culminated in the model of the logarithmic law, a better fit to the experimental data for a number of sensory channels has been demonstrated by Stevens with a psychophysical power law [325]:

where is the subjective magnitude, S is the physical stimulus intensity and m is a modality-dependent exponent. Table 1.3 summarizes some values of the exponent estimated by Stevens:

Table 1.3 : Exponents for the psychophysical law (taken from [325])

Esprit Project 8579/MIAMI (Schomaker et al., '95)
Thu May 18 16:00:17 MET DST 1995