Madden-Rusnak Anna, Micheletti Megan, Bailey Loryn, de Barbaro Kaya
Department of Psychology, the University of Texas at Austin, Austin, TX 78712, United States.
Department of Psychology, the University of Texas at Austin, Austin, TX 78712, United States.
Infant Behav Dev. 2025 Mar;78:102021. doi: 10.1016/j.infbeh.2024.102021. Epub 2024 Dec 18.
Physical contact between infants and caregivers is crucial for attachment development. Previous research shows that skin-to-skin contact after birth and frequent baby wearing in the first year predict secure attachment at 12-months. This relationship is thought to be mediated by the activation of infants' parasympathetic nervous system through caregiver touch. However, little is known about everyday touch behaviors and their impact on infants' real-time parasympathetic activity. Laboratory observations may not accurately represent real-world interactions, highlighting the need for ecologically valid studies. To address this, we examined everyday dyadic touch behaviors and their real-time effects on infant parasympathetic activation. We video recorded N = 28 infants (1-10 months old) and their mothers at home for behavioral analyses. All infants wore wireless ECG sensors (1024 Hz) during video recordings, and n = 21 infants had high-quality ECG data that could be used for Respiratory Sinus Arrhythmia analyses. We used a dynamic measure of RSA (updated every 200 ms) as an index for real-time parasympathetic activation. We found that dyads touch interactions at home involve short, though highly variable bouts of physical contact, that change with infant age. Younger infants spent more time remaining stationary during contact and receiving more soothing touch compared to older infants. Only soothing touch - i.e., rocking, patting, bouncing, or stroking- led to immediate, significant increases in parasympathetic activity (RSA), and this effect was driven by younger infants. This study provides new insights into the ecological patterns of touch in early development and the biobehavioral mechanisms promoting secure attachment.
婴儿与照顾者之间的身体接触对依恋关系的发展至关重要。先前的研究表明，出生后的皮肤接触以及第一年频繁的背抱行为可预测12个月大时的安全依恋。这种关系被认为是通过照顾者的触摸激活婴儿的副交感神经系统来介导的。然而，对于日常触摸行为及其对婴儿实时副交感神经活动的影响知之甚少。实验室观察可能无法准确反映现实世界中的互动，这凸显了进行生态有效研究的必要性。为了解决这个问题，我们研究了日常的二元触摸行为及其对婴儿副交感神经激活的实时影响。我们对N = 28名1至10个月大的婴儿及其母亲在家中进行了录像，以便进行行为分析。在录像过程中，所有婴儿都佩戴了无线心电图传感器（1024Hz），其中n = 21名婴儿拥有可用于呼吸性窦性心律不齐分析的高质量心电图数据。我们使用了动态的呼吸性窦性心律不齐测量方法（每200毫秒更新一次）作为实时副交感神经激活的指标。我们发现，在家中的二元触摸互动涉及短暂但高度可变的身体接触回合，且会随着婴儿年龄的变化而变化。与年龄较大的婴儿相比，年龄较小的婴儿在接触过程中保持静止的时间更长，接受的安抚性触摸更多。只有安抚性触摸，即摇晃、轻拍、弹跳或抚摸，会导致副交感神经活动（呼吸性窦性心律不齐）立即显著增加，且这种效果在年龄较小的婴儿中更为明显。这项研究为早期发育中触摸的生态模式以及促进安全依恋的生物行为机制提供了新的见解。
