Emotion differentiation through features of eye-tracking and pupil diameter for monitoring well-being

Emotions are an important contributor to human self-expression and well-being. However, many populations express their emotions differently from what is considered "typical". Previous literature has indicated a possible relationship between emotion and eye-movement. The objective of this paper is to further explore this proposed relationship by identifying specific features of eye-movement that relate to six emotion categories: joy, surprise, indifference, disgust, sadness, and fear. Features of eye-movement are extracted from measurements of pupil diameter, saccades, and fixations. These measurements are collected as participants view images from the International Affective Picture System, a validated image deck used to evoke known levels of pleasure, arousal, and dominance. Example features of eye-movement measurements such as pupil diameter include maximum or minimum values, means, and standard deviations. Statistical analyses indicate that the extracted features of eye-tracking in this paper can identify fear and sadness with relative accuracy, while more work is needed to differentiate among joy, indifference, disgust, and surprise. Future work aims to understand differences between typically developing populations such as the individuals included in this analysis, and clinical populations such as individuals with cerebral palsy.Clinical Relevance— This pilot study suggests a link between emotion and features of eye-movement. The information will later be used to develop assistive communication devices that better meet the self-expression needs of individuals with motor and communication challenges.