JMIR Publications

ABSTRACT

Background:

Adolescence is a critical developmental period during which physical activity, sleep, digital media engagement, cognition, and emotional health become increasingly interconnected. However, much of the existing literature relies on retrospective self-report or low-frequency longitudinal assessments, limiting understanding of how these behaviors dynamically interact in daily life. Ecological momentary assessment (EMA), passive smartphone sensing, wearable technologies, and mobile cognitive assessment provide opportunities to capture these processes in naturalistic settings, yet few studies have integrated these approaches within mother-child dyads.

Objective:

The Lion Tracks study aims to evaluate the feasibility and acceptability of a multimodal ambulatory monitoring protocol integrating EMA, passive smartphone sensing, wearable monitoring, and mobile cognitive assessment in mother-child dyads. A secondary objective is to explore within-person, between-person, and dyadic relationships among physical activity, sleep, digital media engagement, physiological arousal, cognition, and momentary anxiety.

Methods:

Lion Tracks is a prospective, observational, micro-longitudinal feasibility study involving approximately 25 mother-child dyads (50 participants). Participants will complete a 4-week ambulatory monitoring protocol that includes baseline assessments; continuous Garmin-based monitoring of physical activity, sleep, and physiological measures; passive smartphone sensing through MetricWire; repeated EMA assessing affect, anxiety, behavioral and social context, and health behaviors; and brief mobile cognitive assessments. A hybrid EMA design combining fixed, pseudo-random, and behavior-contingent prompts will be used to capture daily experiences while minimizing participant burden. Primary feasibility outcomes will include participant retention and adherence, wearable-device compliance, EMA completion, and multimodal data completeness, alongside participant-reported acceptability. Exploratory analyses will use multilevel mixed-effects models to examine within-person and between-person associations among behavioral, physiological, cognitive, and emotional measures. Time-lagged and cross-lagged analyses will further explore temporal relationships and behavioral synchrony within mother-child dyads.

Results:

Recruitment and data collection for the Lion Tracks study are planned to begin in September 2026. Approximately 25 mother-child dyads (50 participants) are expected to complete the 4-week protocol. Data collection is anticipated to be completed by January 2027, with findings used to evaluate protocol feasibility and guide refinement of subsequent phases of the Lion Tracks research program.

Conclusions:

Lion Tracks will establish the feasibility of integrating multimodal ambulatory assessment methods to characterize behavioral, cognitive, physiological, and emotional dynamics within mother-child dyads in naturalistic settings. Findings will inform optimization of the monitoring protocol and subsequent research incorporating mobile electroencephalography to investigate neural mechanisms underlying daily health behaviors and emotional regulation. This scalable platform may ultimately support precision behavioral health research and the development of family-centered interventions targeting physical activity, mental health, and cognitive functioning.