Can’t ignore surrounding shapes: Neural processing mechanisms of safety sign designs

Abstract

Effective safety sign design is one of the keys to accident prevention. However, the role of one design element, namely the surrounding shape, has been questioned. It may boil down to that the previous research of surrounding shapes did not reveal the net effect of shape per se. Meanwhile, the researches mostly use subjective measurement methods, such as questionnaires, which do not allow for studying the unconscious and conscious responses of people to the abstract shapes, resulting in less understanding of the role of the surrounding shape. In this study, we designed four tasks to reveal the neural processing mechanisms of pure surrounding shapes and shapes combined with pictorial symbols by using the neuroscience method (event-related potentials, ERPs). The results demonstrate that surrounding shape can convey emotional information without any context, and triangles convey negative emotion more and earlier than circles. Besides, incorporating neutral pictorial symbols into the shapes can make the cognitive processing of the combined signs earlier while not influence the degree of processing compared to pure shapes. Furthermore, the combined signs (shapes + symbols) exhibit effects on processing at two stages: early emotion perceptual processing of the surrounding shape and subsequent cognitive processing guided by neutral pictorial symbols. Therefore, the current study can deepen our understanding of surrounding shape effect and provide effective solutions for safety sign designers to facilitate the efficiency of safety signs and reduce the occurrence of hazards and accidents.