A Protocol to Acquire Infant Heart Rate Variability in the Rohingya Camps and Surrounding Communities in Cox's Bazar, Bangladesh.

Regulation of autonomic arousal during infancy is critical for the development of self-regulation, socioemotional development and cognitive functioning. High frequency heart rate variability (HRV), a key indicator of parasympathetic nervous system function, supports physiological regulation and emerging behaviors that foster social engagement during this critical developmental period. However, research on HRV has largely been confined to controlled settings with highly resourced populations, limiting its applicability to culturally and contextually diverse populations. This study presents a protocol for collecting HRV data from 1-month-old infants in remote and low-resource field contexts, specifically, the Rohingya camps and surrounding host communities in Cox's Bazar, Bangladesh. We present a three-step process to address challenges inherent to working in such contexts while ensuring ecological validity and cultural sensitivity, navigating logistical challenges, and optimizing data quality. Data quality metrics in 148 infants showed high usability, with 86% of data being usable when infants were held by their mothers (joint condition), and 80% when they were alone (solo condition). Aligning with theoretical expectations, higher respiratory sinus arrhythmia (RSA, extracted from HRV) was negatively correlated with behavioral arousal (e.g., more alert, exhibiting motor activity) in both conditions. RSA also remained stable across 30-s segments within each baseline condition, indicating no systematic change in mean RSA levels across time. This study demonstrates a scalable, ethical approach to collecting HRV data in remote field settings, providing a foundation for exploring how early autonomic development intersects with proximal processes such as caregiving across diverse cultural contexts. This protocol aims to advance equity and inclusivity in developmental psychophysiology while maintaining rigorous scientific standards.