Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands.
Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam (UvA), Amsterdam, The Netherlands.
Sci Rep. 2020 Feb 17;10(1):2763. doi: 10.1038/s41598-020-59680-2.
Emotional contagion, the ability to feel what other individuals feel without necessarily understanding the feeling or knowing its source, is thought to be an important element of social life. In humans, emotional contagion has been shown to be stronger in women than men. Emotional contagion has been shown to exist also in rodents, and a growing number of studies explore the neural basis of emotional contagion in male rats and mice. Here we explore whether there are sex differences in emotional contagion in rats. We use an established paradigm in which a demonstrator rat receives footshocks while freezing is measured in both the demonstrator and an observer rat. The two rats can hear, smell and see each other. By comparing pairs of male rats with pairs of female rats, we found (i) that female demonstrators froze less when submitted to footshocks, but that (ii) the emotional contagion response, i.e. the degree of influence across the rats, did not depend on the sex of the rats. This was true whether emotional contagion was quantified based on the slope of a regression linking demonstrator and observer average freezing, or on Granger causality estimates of moment-to-moment freezing. The lack of sex differences in emotional contagion is compatible with an interpretation of emotional contagion as serving selfish danger detection.
情绪感染，即无需理解某种感受或知晓其来源而能够感受到他人感受的能力，被认为是社会生活的一个重要元素。在人类中，情绪感染在女性中比男性更强。情绪感染也存在于啮齿动物中，越来越多的研究探索了雄性大鼠和小鼠情绪感染的神经基础。在这里，我们探讨了大鼠中是否存在情绪感染的性别差异。我们使用了一种已建立的范式，在该范式中，一只示范大鼠接受电击，同时测量示范大鼠和观察大鼠的冻结行为。两只大鼠可以听到、闻到和看到彼此。通过比较雄性大鼠和雌性大鼠的配对，我们发现：（i）当接受电击时，雌性示范大鼠冻结的程度较低，但（ii）情绪感染反应，即大鼠之间的影响程度，并不取决于大鼠的性别。无论是基于将示范和观察大鼠平均冻结值关联起来的回归斜率来量化情绪感染，还是基于对大鼠冻结的逐点进行格兰杰因果关系估计，结果都是如此。情绪感染中不存在性别差异，这与情绪感染作为一种自私的危险检测机制的解释是一致的。
