Past studies have reported that language-specific color focality has substantial influence on short-term memory (STM) performance of colors of the speakers of the language, which we call the “focality effect.” This study attempts to clarify the continuous patterns of this effect, that is, the manner in which correct recognition possibilities and misrecognition error distances of colors, which are two aspects of the STM performance of colors, change in a gradual fashion along the continuum of color focality. Our experiment, which tests the Japanese language, finds that a U-shaped relationship exists between the focality and the possibility of correct recognition, and that the misrecognition error distance increases as the focality decreases. We speculate that the subjects' frequent and conscious employment of the memorization strategy of coding colors using linguistic color categories is one important cause of the detected effect patterns.
To effectively design tactile textures of product surfaces, it is essential to specify the semantically multilayered and multidimensional structure of human perceptual, emotional, and preferential expressions pertaining to touching materials. We implemented a method to identify individual differences in the structure of these expressions, based on subjective reports of the mutual impacts among 29 adjective dyads used to describe tactile experiences of material samples. Results showed that the 11 university students who responded to 46 types of flat materials were clustered into three statistically different groups. The structures were largely composed of three layers of expressions: psychophysical (bottom), emotional or material attributes (middle), and preferential (top). All groups selected the same adjective dyads encompassed in the bottom layer, relating to percepts of physical quantities, which indicates the similarity of psychophysical percepts among the participants; however, the middle and top layers significantly differed across individuals. These results indicate that under the tested conditions, there are individual differences in the semantic structures of emotional and preferential experiences; however, such differences in psychophysical expressions are relatively minor.