School of Psychology, University of Sydney, Sydney, New South Wales, Australia.
PLoS One. 2012;7(8):e44014. doi: 10.1371/journal.pone.0044014. Epub 2012 Aug 28.
Oxytocin (OT) plays a key regulatory role in human social behaviour. While prior studies have examined the effects of OT on observable social behaviours, studies have seldom examined the effects of OT on psychophysiological markers such as heart rate variability (HRV), which provides an index of individual's motivation for social behaviour. Furthermore, no studies have examined the impact of OT on HRV under resting conditions, which provides an index of maximal capacity for social engagement.
To examine the effects of OT on HRV measures in healthy male participants while at rest. OT was hypothesised to increase HRV, compared to placebo, and that the effects would be greatest for a non-linear measure of HRV (the detrended fluctuation scaling exponent).
Twenty-one male participants were recruited for this study. Participants were non-smokers, not on any medications and reported no history of psychiatric illness, neurological disorder, or any other serious medical condition (e.g. diabetes, cardiovascular disease). The study employed a randomised, placebo-controlled, within-subject, crossover, experimental design.
HRV was calculated from electrocardiography under a standardized, 10-minute, resting state condition.
As hypothesised, OT increased HRV and these effects were largest using the detrended fluctuation scaling exponent, a non-linear measure. These changes were observed in the absence of any change in state mood, as measured by the profile of mood states. Importantly, participants were unable to correctly guess which treatment they had been assigned at either of the two assessments.
Together with the broader literature on OT and HRV, findings suggest that acute administration of OT may facilitate a fundamental psychophysiological feature of social behaviour, increasing capacity for social engagement. Findings also suggest that HRV changes may provide a novel biomarker of response to OT nasal spray that can be incorporated into research on response to treatment.
催产素（OT）在人类社会行为中起着关键的调节作用。虽然先前的研究已经检验了 OT 对可观察到的社会行为的影响，但很少有研究检验 OT 对心理生理标志物的影响，如心率变异性（HRV），它提供了个体社会行为动机的指标。此外，没有研究在静息状态下检查 OT 对 HRV 的影响，这提供了最大社交参与能力的指标。
在健康男性参与者静息时，检查 OT 对 HRV 测量的影响。假设 OT 会增加 HRV，与安慰剂相比，而对 HRV 的非线性测量（去趋势波动标度指数）的影响最大。
这项研究招募了 21 名男性参与者。参与者不吸烟，没有服用任何药物，也没有报告过精神疾病、神经障碍或任何其他严重疾病的病史（如糖尿病、心血管疾病）。该研究采用了随机、安慰剂对照、单盲、交叉、实验设计。
在标准化的 10 分钟静息状态下，从心电图计算 HRV。
正如假设的那样，OT 增加了 HRV，这些影响在使用去趋势波动标度指数（一种非线性测量）时最大。这些变化是在没有任何情绪状态变化的情况下观察到的，情绪状态的特征是通过测量来评估的。重要的是，参与者在两次评估中都无法正确猜测他们被分配了哪种治疗。
结合催产素和 HRV 的更广泛文献，研究结果表明，急性给予 OT 可能有助于促进社会行为的基本心理生理特征，增加社交参与能力。研究结果还表明，HRV 变化可能为 OT 鼻喷剂反应的新型生物标志物提供依据，可纳入治疗反应的研究中。
