Institut des Sciences Cognitives Marc Jeannerod, UMR5229 CNRS, Université de Lyon, 67 Boulevard Pinel, 69675, Bron Cedex, France.
Risk-Eraser, LLC, PO Box 376, West Falmouth, MA, 02574, USA.
Sci Rep. 2020 Oct 21;10(1):17940. doi: 10.1038/s41598-020-74954-5.
Heart rate (HR) is extremely valuable in the study of complex behaviours and their physiological correlates in non-human primates. However, collecting this information is often challenging, involving either invasive implants or tedious behavioural training. In the present study, we implement a Eulerian video magnification (EVM) heart tracking method in the macaque monkey combined with wavelet transform. This is based on a measure of image to image fluctuations in skin reflectance due to changes in blood influx. We show a strong temporal coherence and amplitude match between EVM-based heart tracking and ground truth ECG, from both color (RGB) and infrared (IR) videos, in anesthetized macaques, to a level comparable to what can be achieved in humans. We further show that this method allows to identify consistent HR changes following the presentation of conspecific emotional voices or faces. EVM is used to extract HR in humans but has never been applied to non-human primates. Video photoplethysmography allows to extract awake macaques HR from RGB videos. In contrast, our method allows to extract awake macaques HR from both RGB and IR videos and is particularly resilient to the head motion that can be observed in awake behaving monkeys. Overall, we believe that this method can be generalized as a tool to track HR of the awake behaving monkey, for ethological, behavioural, neuroscience or welfare purposes.
心率（HR）在非人类灵长类动物复杂行为及其生理相关性的研究中非常有价值。然而，收集这些信息通常具有挑战性，需要进行侵入性植入或繁琐的行为训练。在本研究中，我们在猕猴中结合使用了基于欧拉视频放大（EVM）的心脏跟踪方法和小波变换。这是基于由于血液流入引起的皮肤反射率图像到图像波动的测量。我们展示了 EVM 基于心脏跟踪和地面实况 ECG 之间的强时间相干性和幅度匹配，来自麻醉猕猴的彩色（RGB）和红外（IR）视频，达到了与人相当的水平。我们进一步表明，这种方法可以识别出呈现同种情感声音或面孔后一致的 HR 变化。EVM 用于提取人类的 HR，但从未应用于非人类灵长类动物。视频光体积描记术可从 RGB 视频中提取清醒猕猴的 HR。相比之下，我们的方法允许从 RGB 和 IR 视频中提取清醒猕猴的 HR，并且特别能够抵抗在清醒行为猴子中观察到的头部运动。总体而言，我们相信这种方法可以推广为一种工具，用于跟踪清醒行为猴子的 HR，用于行为学、行为学、神经科学或福利目的。
