JMIR Publications

ABSTRACT

Adolescence is a critical developmental period during which physical activity, sleep, digital-media engagement, cognition, and emotional health become increasingly interconnected. However, most studies rely on retrospective self-report or low-frequency longitudinal designs, limiting understanding of how these behaviors dynamically interact within individuals and families in daily life. Although ecological momentary assessment (EMA), passive sensing, and wearable technologies have advanced real-world behavioral measurement, few studies have integrated these approaches within mother-child dyads to examine temporal relationships among health behaviors, cognition, and anxiety. Lion Tracks is a prospective, observational, micro-longitudinal feasibility study designed to evaluate the integration of EMA, passive smartphone sensing, wearable monitoring, and mobile cognitive assessment to characterize real-world behavioral and emotional dynamics in mother-child dyads. Approximately 25 mother-child dyads (50 participants) will complete a four-week ambulatory monitoring protocol consisting of baseline assessments, continuous Garmin-based monitoring of physical activity, sleep, and physiological measures, passive smartphone sensing through MetricWire, repeated EMA of affect, anxiety, context, and behaviors, and brief mobile cognitive testing. The protocol incorporates a hybrid EMA design that combines fixed, pseudo-random, and behavior-contingent prompts to capture daily experiences while minimizing participant burden. The primary aim is to evaluate protocol feasibility, acceptability, participant adherence, wearable-device compliance, EMA completion, and data completeness to inform refinement of subsequent study phases. Secondary exploratory analyses will examine within-person and between-person associations among physical activity, sleep, smartphone-based digital-media engagement, physiological arousal, cognition, and momentary anxiety using multilevel mixed-effects models. Time-lagged and cross-lagged analyses will also explore temporal relationships and behavioral synchrony within mother-child dyads. Lion Tracks represents the first phase of a larger research program designed to progressively optimize ambulatory monitoring and ultimately incorporate mobile electroencephalography (EEG) to investigate neural mechanisms underlying daily health behaviors and emotional regulation. By establishing the feasibility of a scalable, multimodal ambulatory monitoring platform, this protocol provides a foundation for future precision behavioral health research and family-centered interventions targeting physical activity, mental health, and cognitive functioning in naturalistic settings.