Tarow Indow

Scaling of dot numerosity

Subjective impression of numerosity of dots randomly scattered in an area of 19.5 × 24.5 cm, 36≈1,010 in number (ϕ), was scaled by four different methods with five subjects. The absolute identification showed that the number of dots is underestimated if ϕ > 10. Each of two scales based uponratio judgments is a power function of

An application of the τ scale of taste: Interaction among the four qualities of taste

with the exponent of 0.87, and each of two scales based upondifference judgments is also a power function of ϕ when the origin of the scale is appropriately defined. The relationship between the four scales and comparison with scales in other sense modalities were discussed from the viewpoint of scaling methodology.

Multidimensional mapping of visual space with real and simulated stars

A series of 10 standard solutions, spaced equidistant on the τ scale, were prepared for each of the basic tastes, sweet, bitter, sour, and salty. In addition, four other concentrations of each basic taste, plus 96 compound solutions of two different solutes, were prepared as test stimuli. The Ss, four specialists in taste testing and four laymen, were asked to specify the taste of each test stimulus by matching it with the standard series. In this way, both the precision of the matching procedure and the enhancement or masking of one taste by another were measured in terms of τ, which is a nearly logarithmic function of concentration. The average standard deviations of the matchings among the Ss were in the order of 0.3 to 0.5 units on the τ scale, which corresponds to a value between 1 and 2 decilogs of concentration. Among the interactions observed was the mutual masking of sucrose and quinine sulfate.

Scaling of Saturation and Hue Shift: Summary of Results and Implications

In each of five experiments Ss made direct assessments of interpoint distances within a stimulus configuration. A multidimensional scaling method was applied to make explicit the form of the subjective configuration. The stimulus configurations consisted of small light points arranged in a two- or three-dimensional array in a dark room, and of real stars in the sky. All the data were adequately accounted for by a configuration constructed in Euclidean space of the appropriate dimensionality. That was true even in the situation where alley experiments with the same Ss gave the result that is usually regarded as evidence for a hyperbolic binocular space. The Euclidean interpretation entails a more complicated form of correspondence between physical and visual spaces than the hyperbolic interpretation.

Scaling of saturation and hue in the nonspectral region

The results were reviewed of experiments in which a difference scale ψD, based upon equisection, and a magnitude scale ψM, based upon ratio judgments, were constructed for saturation of various hues as well as for hue shift between two adjacent primary hues of aperture colors. The same nonlinearity between ψD and ψM as in prothetic continua was found for the saturation and the hue shift; this seems to suggest that saturation is a quantitative change of balance between two components, chromatic and achromatic, and that the hue shift is between the two primary hue components. A number of anomalous results were observed with yellow. The implications of these results for opponent color theory are discussed.

Concept identification with natural material

The saturation of two nonspectral hues, magenta and violet, and the hue shift between red and blue through the nonspectral region were both scaled by two methods, equisection to produce a difference scale, ψD, and ratio judgments to produce a magnitude scale, ψM. The colored stimuli were viewed through apertures in a dark surround, with the luminance kept constant at one of three levels, 0.5, 2.5, and 12.6 cd/m2. As previously found with saturation and hue shift between two adjacent primary hues in the spectral region, WD was linear with colorimetric purity for the saturation of magenta or violet and with the mixture ratio of red or blue for the hue shift, whereas ψM was a power function of colorimetric purity for the saturations and of the mixture ratio for the hue shift with exponents larger than unity in both cases. The present results were combined with previous results to give the change of parameters for saturation functions over the entire hue circle.

Alleys in visual space

Phonetic letters in Japanese (Hiragana, 23 in number) written by 6 adults (Ws) were presented one by one and the S was asked to guess by which W it was written. Immediately after the S made the guess, the code of correct W was given on each trial. The Ss were Japanese housewives, students etc., 53 in number. Rate of correct identification increased during 23 × 6 trials, but only from 0.3 to 0.4 on the average. The learning transferred to the remaining 23 letters of the same kind but not to letters of the other kind (Katakana). On each trial, the S verbally described cues upon which the guess was made. When the data were separately analysed according to Ws, it was found that letters of the W who was most difficult to identify were most ‘diffused’ in characterization by the Ss. The relevance of the present experiment to study of concept identification in general was also discussed.