In many products, the visual impressions of the product are extremely important components—sight accounts for 83 % of the five senses (An education apparatus editing committee in An industrial education apparatus system manual. JUS Press 1972). However, manufacturers still depend on the aspect of the effectiveness, efficiency, and usability for the design evaluation of products; yet, consumer emotion is hard to measure because the mental side of users such as visual impressions cannot be observed directly and the index to measure them has not been established. The function, performance, and usability can be measured by the behavioral index of users (e.g., operation time and error rate) (Nagashima and Kubo in The sensitivity and information for the new manufacturing. Morikita Shuppan Co., Ltd, 2007). In this study, we experimentally searched for indices to objectively detect the impression of appearance with car images as targets. We observed that MPFC activation is related to high “familiarity” and low “mechanical” features.