Are We Sensitive to Different Types of Safety Signs? Evidence from ERPs

PURPOSE: Safety signs are widely used to deliver safety-related information. There are many different types of safety signs. Although previous studies have paid attention to the design and effectiveness of safety signs, little attention has been devoted to investigating how people process the information conveyed by different types of safety signs. Accordingly, the current study is intended to explore the neural mechanisms underlying people’s perception of different types of safety signs. METHODS: Three types of safety signs (prohibition, mandatory and warning signs) were used in the study. We employed questionnaire and event-related potentials (ERPs) experiment with an implicit paradigm to probe how people perceive these three types of safety signs. RESULTS: Behaviorally, warning signs induced a higher level of perceived hazard than prohibition signs and mandatory signs, and prohibition signs induced a higher level of perceived hazard than mandatory signs. At the brain level, prohibition signs and warning signs led to reduced P2 amplitudes compared to mandatory signs. In addition, warning signs elicited larger N2 and N4 amplitudes than prohibition signs and mandatory signs, and prohibition signs elicited larger N2 and N4 amplitudes than mandatory signs, coinciding with the behavioral results. CONCLUSION: Different types of safety signs led to significant differences in individuals’ hazard perception. Based on the neural results, we suggest that the processing of safety signs consists of two stages: the rapid detection of hazard information (indicated by P2) and the conscious integration of hazard information in working memory (indicated by N2 and N4).