Abstract
Though we can discriminate different material categories (e.g., metal, fabric, glass, etc.) at a glance, perceptual surface qualities (e.g., glossiness, transparency, texture, etc.) effective for the material category discrimination are unclear. We investigated the effects of stimulus durations on a material discrimination task and surface quality judgment tasks to know the relationship between perceptual surface qualities and material discrimination. In the experiments, the observers were presented with two object images with an identical three-dimensional shape but made of different materials from seven categories (metal, plastic, glass, stone, wood, leather and fabric) for 30 ~ 100 ms. They performed two kinds of tasks after the stimulus presentation: a material discrimination task and surface quality judgment tasks. In the material discrimination task, they responded if the material categories of the two objects were the same or not. In the surface quality judgment tasks, they responded which of the two objects was more glossy, rougher, or heavier (glossiness, roughness, and heaviness tasks, respectively). First, the performance of all the tasks increased with the stimulus duration as expected. However, the increase rate was much lower for the heaviness tasks than the other two surface quality tasks, even when the task difficulties were equalized between the three tasks. Second, the correlation between the performance of the material discrimination task and perceptual scores for different surface qualities measured in another experiment increased with the stimulus duration for glossiness and roughness scores, but not for heaviness scores at all. These temporal properties of surface quality perception suggest at least two kinds of surface qualities: one quickly processed and utilized for higher-order material perception (e.g., material categorization), and the other slowly processed and not utilized for higher-order material perception. The latter might be derived only via top-down processes from material recognition.
Meeting abstract presented at VSS 2013