Individual differences in perceptual space for tactile textures: Evidence from multidimensional scaling

Ratio scaling was used to obtain from 5 subjects estimates of the subjectiv e dissimilarity between the members of all possible pairs of 17 tactile sur faces. The stimuli were a diverse array of everyday surfaces, such as cordu roy, sandpaper, and synthetic fur. The results were analyzed using the mult idimensional scaling (MDS) program ALSCAL. There was substantial, but not c omplete, agreement across subjects in the spatial arrangement of perceived textures. Scree plots and multivariate analysis suggested that, for some su bjects, a two-dimensional space was the optimal MDS solution, whereas for o ther subjects, a three-dimensional space was indicated. Subsequent to their dissimilarity scaling, subjects rated each stimulus on each of five adject ive scales. Consistent with earlier research. two of these (rough/smooth an d soft/hard) were robustly related to the space for all subjects. A third s cale, sticky/slippery, was more variably related to the dissimilarity data: regressed into three-dimensional MDS space, it was angled steeply into the third dimension only for subjects whose scree plots favored a nonplanar so lution. We conclude that the sticky/slippery dimension is perceptually weig hted less than the rough/smooth and soft/hard dimensions, materially contri buting to the structure of perceptual space only in some individuals.