Department of Neuroscience, University Medical Center Groningen, Groningen, The Netherlands.
PLoS One. 2011;6(11):e27272. doi: 10.1371/journal.pone.0027272. Epub 2011 Nov 16.
Why does chanting, drumming or dancing together make people feel united? Here we investigate the neural mechanisms underlying interpersonal synchrony and its subsequent effects on prosocial behavior among synchronized individuals. We hypothesized that areas of the brain associated with the processing of reward would be active when individuals experience synchrony during drumming, and that these reward signals would increase prosocial behavior toward this synchronous drum partner. 18 female non-musicians were scanned with functional magnetic resonance imaging while they drummed a rhythm, in alternating blocks, with two different experimenters: one drumming in-synchrony and the other out-of-synchrony relative to the participant. In the last scanning part, which served as the experimental manipulation for the following prosocial behavioral test, one of the experimenters drummed with one half of the participants in-synchrony and with the other out-of-synchrony. After scanning, this experimenter "accidentally" dropped eight pencils, and the number of pencils collected by the participants was used as a measure of prosocial commitment. Results revealed that participants who mastered the novel rhythm easily before scanning showed increased activity in the caudate during synchronous drumming. The same area also responded to monetary reward in a localizer task with the same participants. The activity in the caudate during experiencing synchronous drumming also predicted the number of pencils the participants later collected to help the synchronous experimenter of the manipulation run. In addition, participants collected more pencils to help the experimenter when she had drummed in-synchrony than out-of-synchrony during the manipulation run. By showing an overlap in activated areas during synchronized drumming and monetary reward, our findings suggest that interpersonal synchrony is related to the brain's reward system.
为什么一起吟唱、击鼓或跳舞会让人感到团结？在这里，我们研究了人际同步的神经机制及其对同步个体亲社会行为的后续影响。我们假设，当个体在击鼓时体验到同步时，大脑中与奖励处理相关的区域会活跃起来，并且这些奖励信号会增加个体对这个同步鼓伴的亲社会行为。18 名非音乐家女性在功能磁共振成像扫描仪中接受扫描，同时她们与两名不同的实验者交替击鼓：一名实验者与参与者同步击鼓，另一名实验者与参与者不同步击鼓。在最后一部分扫描中，作为随后亲社会行为测试的实验操作，一名实验者与一半参与者同步击鼓，与另一半不同步击鼓。扫描后，这位实验者“不小心”掉了八支铅笔，参与者收集的铅笔数量作为亲社会承诺的衡量标准。结果显示，在扫描前轻松掌握新节奏的参与者在同步击鼓时尾状核活动增加。同一区域在同一参与者的局部定位任务中对金钱奖励也有反应。在体验同步击鼓时尾状核的活动也预测了参与者在实验操作中稍后收集的铅笔数量，以帮助同步实验者。此外，当实验者在操作中同步击鼓时，参与者会收集更多的铅笔来帮助她，而不是不同步击鼓时。通过显示同步击鼓和金钱奖励时激活区域的重叠，我们的发现表明人际同步与大脑的奖励系统有关。
