Designing App Interfaces to Elicit Specific Emotional Responses and Improve Attention and Short-Term Memory in Patients With Insomnia Undergoing Brief Cognitive Behavioral Therapy: Within-Subject Eye-Tracking Experimental Pilot Study.

Background: Patients with insomnia have difficulty in both falling asleep and maintaining sleep. Individuals with long-term sleep deprivation are prone to poor concentration and impaired memory; however, these problems can be alleviated following brief behavioral treatment for insomnia (BBT-I). This study involved the design of an app called "Sleep Well" that enables individuals with insomnia to easily record their sleep behavior. The app guides users to recall and record sleep-related information, acquire sleep hygiene knowledge, and communicate with therapists online. Objective: This study examined how specific sleep diary interface design features in a brief cognitive behavioral therapy for insomnia (BBT-I) app influence users' attention and short-term memory. Using a combination of objective eye-tracking measures and subjective attention assessments, the study compared 3 interface designs to determine how visual layout, input modality, and interaction style interact with insomnia symptoms to affect attentional performance, memory accuracy, and user preference. Methods: Three sleep diary interfaces were designed, varying background mode (day vs night), color scheme (blue vs green), box shape (circular, rounded rectangular, or rectangular), and input method (slide-in, tap, or type-in). A total of 33 participants completed standardized diary-entry tasks while eye movements were recorded using an eye tracker to capture gaze trajectories and visual attention patterns during app interaction. User experience, subjective attention, and interface preferences were assessed using structured questionnaires. Data were analyzed using descriptive statistics, nonparametric tests, Pearson correlation analysis, cross-tabulation analysis, and exploratory factor analysis to examine associations among interface design, attentional performance, memory accuracy, and user characteristics. Results: A total of 33 participants (n=13, 39.4% male and n=20, 60.6% female) aged 20 to 64 years completed this study. Based on the Insomnia Severity Index, 6 of 33 (18.2%) participants had clinical insomnia and 13 of 33 (39.4%) reported insomnia symptoms. Most participants reported staying up late (22/33, 66.7%), and more than half of participants reported drinking tea (17/33, 51.5%). Interface design significantly influenced objective attentional performance, as measured by eye-tracking indicators of task efficiency and visual allocation. Sleep quality and insomnia symptoms were consistently associated with attentional and short-term memory outcomes, with memory accuracy varying across interfaces and showing particular sensitivity to sleep maintenance difficulties. Subjective attentional control was strongly associated with both eye-tracking metrics and memory performance, and interface preferences differed by insomnia status. Conclusions: Interface design significantly modulates attention and short-term memory performance in users with insomnia. Eye-tracking revealed that insomnia symptoms and sleep quality influence visual attention and task efficiency, whereas subjective attentional control showed stronger and more consistent associations with memory accuracy than physiological eye-movement indicators. These findings suggest that cognitive processing during sleep diary completion relies more on internal attentional states than on observable gaze behavior. Designing low-load, attention-supportive interfaces may therefore improve usability and data accuracy in digital BBT-I interventions.