On the ability to directly evaluate sensory ratios

Abstract

The study explored whether participants could directly evaluate sensory ratios. The results indicate that they did not exhibit this ability for the extensive continuum of length and the intensive continua of brightness and brightness difference. Functional measurement analysis, combined with a chronometric analysis of responses, indicated that participants used mental counting for length and used difference evaluation for brightness and brightness difference. The finding that participants evaluated brightness differences under instructions to evaluate brightness ratios suggests that difference judgments may be a general human capability. It resolves questions raised by prior tests of Torgerson's conjecture and by prior consistency tests of ratio evaluation.

Tests of the abilities to judge ratios of extensive and intensive sensory magnitudes

“…Empirically, the factorial curves relating J to B V have been found to be statistically parallel to each other (Masin, 2013(Masin, , 2014. Because Eq.…”

“…People can numerically judge ratios between pairs of lengths in the frontoparallel plane by very quickly counting how many times the shorter length is contained in the longer length (Hartley, 1977(Hartley, , 1981Krantz, 1972;Masin, 2013;Masin & Anali, 2011;Reed, Hock, & Lockhead, 1983). This ability receives support from the finding of a high correlation between judgments of ratios of perceived distance and the corresponding ratios of physical distance (Baird, 1970;Norman et al, 2017;Norman, Adkins, & Pedersen, 2016).…”

“…Each step of such concatenation takes time. For example, it normally takes about 1.5 s to report a length ratio of 1:3, and about 2.5 s to report a ratio of 1:8 (Masin, 2013). If we were equipped with a neural mechanism that directly converted ratios of sensory length into numerical responses, all judgments of ratios should instead take the same time.…”

“…That is, the time required to numerically judge the ratio between two brightness values seems to be independent of the ratio between these values. For example, unlike with judgments of length ratios, it takes about 1.5 s both to report a brightness ratio of 1:3 and to report one of 1:8 (Masin, 2013).…”

Test of the Ratio Judgment Hypothesis

“…For combinations of variable subjective intensities V with standard subjective intensities S, with S smaller than any V, Masin (2013) had participants judge how many times V was larger than S. If participants judge ratios, these judgments are…”