Visual attention during neonatal pain assessment: A 2‐s exposure to a facial expression is sufficient

Abstract Newborn infants are exposed to painful experiences, routinely practised clinically, that might increase their short‐ and long‐term morbidity and mortality. Facial expression has been widely used in clinical practice to assess pain in newborns. However, the inherent human visual attention required to make such vital inference is poorly understood. It is also unknown whether this inference occurs differently when comparing health professionals with non‐health ones. To investigate these issues, the authors have recorded and monitored the pupil size signal of 102 subjects (44 experts, 29 parents, and 29 non‐experts) while visually analyzing 20 frontal face images of 10 distinct newborns after a painful procedure (positive stimulus) and at painless rest (negative stimulus). Our experimental results show that neonatal pain assessment is more cognitively demanding when analyzing the presence of pain rather than its absence. In addition, the pupil responses for both positive and negative stimuli and all sample groups of subjects present experimentally a common temporal pattern, disclosing that a 2‐s exposure to a facial expression is sufficient to make this assessment, regardless of whether performed by health professionals or non‐health ones.