Effects of Visual Expectation on Perceived Tactile Perception: An Evaluation Method of Surface Texture with Expectation Effect

Hideyoshi Yanagisawa, Kenji Takatsuji

Human beings predict modal perceptions using a prior modality; for example, they might predict a product’s tactile quality based on its appearance before they have touched it. In this paper, we propose a method for evaluating the quality of surface textures by focusing on the effects of a prior visual prediction on posterior tactual experience, a phenomenon known as the expectation effect. Using a half-mirror apparatus, we synthesized differing combinations of visual and tactile samples. We then compared the expectation effects on perceptual responses to texture samples synthesized using different visual samples. This method was used in an experiment in which participants responded to tactile quality (“nice to touch”) and perceived features (e.g., roughness, hardness, stickiness) of plastic textures under three conditions: visual expectation (V), touch alone (T), and touch following a visual expectation (VT). For the VT condition, participants were asked to evaluate congruent combinations (i.e., identical visual and tactile samples) and incongruent combinations (i.e., tactile samples synthesized with different visual samples). Responses to the tactile samples differed depending on the synthesized visual sample. Comparisons of the responses for V and T conditions revealed expectation effects for contrast and assimilation. It was found that the qualities of both “roughness” and “stickiness” significantly affected tactile quality evaluations. Thus, it is shown that our proposed method can help identify visual-tactile combinations that can improve perceived tactile texture quality.