Eye movement entropy: a new metric for quantitative analysis of visual scanning

Abstract: Eye movement entropy (EME) is an objective measurement index for studying eye movement behavior, developed based on information entropy. It is primarily used to assess the complexity and randomness of visual scanning behavior, addressing the limitations of traditional eye movement metrics in comprehensively characterizing individuals’ complex visual scanning patterns. EME consists of two core indices: fixation entropy and heatmap entropy. Depending on the calculation method, fixation entropy can be further categorized into static fixation entropy, fixation transition entropy, and fixation duration entropy.  A review of previous studies reveals that EME has been widely applied in various fields, including mental disorders, driving safety, aviation safety, education and teaching, product design, and industrial safety. It demonstrates significant potential in assisting with mental disorder diagnosis, cognitive function assessment, safety monitoring, education evaluation, and human factors engineering. As a crucial tool for studying human visual cognition, behavioral patterns, and information processing, future research should focus on improving the robustness and ecological validity of EME measurements, continuously refining the EME index system, and promoting a shift in eye movement data analysis from static statistics to dynamic behavioral pattern exploration. This will enable a more comprehensive understanding of human visual cognition mechanisms and expand the practical value of EME across various application domains.