Department of Psychology, University of Alberta, Edmonton, Alberta, Canada.
Department of Psychology, Boston College, Chestnut Hill, Massachusetts, USA.
Psychophysiology. 2018 Apr;55(4). doi: 10.1111/psyp.13005. Epub 2017 Sep 21.
Heart rate, measured in beats per minute, can be used as an index of an individual's physiological state. Each time the heart beats, blood is expelled and travels through the body. This blood flow can be detected in the face using a standard webcam that is able to pick up subtle changes in color that cannot be seen by the naked eye. Due to the light absorption spectrum of blood, we are able to detect differences in the amount of light absorbed by the blood traveling just below the skin (i.e., photoplethysmography). By modulating emotional and physiological stress-that is, viewing arousing images and sitting versus standing, respectively-to elicit changes in heart rate, we explored the feasibility of using a webcam as a psychophysiological measurement of autonomic activity. We found a high level of agreement between established physiological measures, electrocardiogram, and blood pulse oximetry, and heart rate estimates obtained from the webcam. We thus suggest webcams can be used as a noninvasive and readily available method for measuring psychophysiological changes, easily integrated into existing stimulus presentation software and hardware setups.
心率以每分钟的跳动次数来衡量，可以作为个体生理状态的指标。每次心脏跳动，血液都会被排出并流经全身。通过标准的网络摄像头可以检测到面部的这种血液流动，这种网络摄像头能够捕捉到肉眼无法看到的细微颜色变化。由于血液的光吸收光谱，我们能够检测到流经皮肤下方的血液吸收光的量的差异（即光体积描记法）。通过调节情绪和生理压力——即观看令人兴奋的图像和分别坐着和站着——来引起心率的变化，我们探讨了使用网络摄像头作为自主活动的心理生理测量的可行性。我们发现，网络摄像头获取的心率估计值与心电图和血液脉搏血氧仪等既定生理测量值之间具有高度一致性。因此，我们建议网络摄像头可作为一种非侵入性且易于获得的测量心理生理变化的方法，可轻松集成到现有的刺激呈现软件和硬件设置中。
