Yankouskaya Ala, Massey Heather, Totman John James, Lai Lin Hui, Williamson Ruth
Department of Psychology, Faculty of Science and Technology, Poole House, Bournemouth University, Fern Barrow, Poole, Dorset, UK.
Extreme Environments Laboratory, School of Sport Health and Exercise Science, Faculty of Science and Heath, Spinnaker Building, Cambridge Road, Portsmouth, Hampshire, UK.
Bio Protoc. 2023 Sep 5;13(17):e4794. doi: 10.21769/BioProtoc.4794.
An emerging body of behavioural studies indicates that regular swimming in cold water has positive effects on mental health and wellbeing, such as reducing fatigue, improving mood, and lessening depressive symptoms. Moreover, some studies reported immediate effects of cold-water immersion (CWI) on elevating mood and increasing a positive emotional state. However, the neural mechanisms underlying these effects remain largely unknown. The lack of studies using neuroimaging techniques to investigate how a whole-body CWI affects neural processes has partly resulted from the lack of a tested experimental protocol. Previous protocols administered tonic limb cooling (1-10 °C) while recording functional magnetic resonance (fMRI) signals. However, using very low water temperature constitutes points of contrast to painful experiences that are different from what we experience after a whole-body head-out CWI. In our protocol, healthy adults unhabituated to cold water were scanned twice: immediately before (pre-CWI) and after (post-CWI) immersion in cold water (water temperature 20 °C) for 5 min. We recorded cardiac and ventilatory responses to CWI and assessed self-reported changes in positive and negative affects. Our protocol showed reliable changes in brain connectivity after a short exposure to cold water, thus enabling its use as a tested experimental framework in future studies.
越来越多的行为学研究表明，经常在冷水中游泳对心理健康和幸福感有积极影响，比如减轻疲劳、改善情绪以及减轻抑郁症状。此外，一些研究报告了冷水浸泡（CWI）对提升情绪和增加积极情绪状态的即时效应。然而，这些效应背后的神经机制在很大程度上仍不为人知。缺乏使用神经成像技术来研究全身冷水浸泡如何影响神经过程的研究，部分原因是缺乏经过测试的实验方案。以往的方案在记录功能磁共振成像（fMRI）信号时采用了肢体强直性冷却（1至10摄氏度）。然而，使用极低的水温与痛苦体验形成对比，这与我们在全身头部露出的冷水浸泡后所经历的不同。在我们的方案中，对不习惯冷水的健康成年人进行了两次扫描：在全身浸入20摄氏度的冷水中5分钟之前（冷水浸泡前）和之后（冷水浸泡后）立即进行扫描。我们记录了对冷水浸泡的心脏和通气反应，并评估了自我报告的正负情绪变化。我们的方案显示，在短时间接触冷水后大脑连接性有可靠的变化，从而使其能够在未来的研究中作为经过测试的实验框架使用。
