Laboratory of Psychophysics, Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
Institute for Systems and Robotics - Lisboa, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
Cereb Cortex. 2018 Oct 1;28(10):3740-3751. doi: 10.1093/cercor/bhy195.
Social dominance, the main organizing principle of social hierarchies, facilitates priority access to resources by dominant individuals. Throughout taxa, individuals are more likely to become dominant if they act first in social situations and acting fast may provide evolutionary advantage; yet whether fast decision-making is a behavioral predisposition of dominant persons outside of social contexts is not known. Following characterization of participants for social dominance motivation, we found that, indeed, men high in social dominance respond faster-without loss of accuracy-than those low in dominance across a variety of decision-making tasks. Both groups did not differ in a simple reaction task. Then, we selected a decision-making task and applied high-density electroencephalography (EEG) to assess temporal dynamics of brain activation through event related potentials. We found that promptness to respond in the choice task in dominant individuals is related to a strikingly amplified brain signal at approximately 240 ms post-stimulus presentation. Source imaging analyses identified higher activity in the left insula and in the cingulate, right inferior temporal and right angular gyri in high than in low dominance participants. Our findings suggest that promptness to respond in choice situations, regardless of social context, is a biomarker for social disposition.
社会支配地位是社会等级制度的主要组织原则,它使占优势的个体优先获得资源。在各个分类群中,如果个体在社交情境中率先行动,并且行动迅速,那么他们更有可能成为支配者,因为快速决策可能提供进化优势;然而,在社交情境之外,支配者是否具有快速决策的行为倾向尚不清楚。在对参与者的社会支配动机进行特征描述后,我们发现,确实,在各种决策任务中,高社会支配力的男性比低社会支配力的男性反应更快——而且准确性没有降低。在简单反应任务中,两组没有差异。然后,我们选择了一个决策任务,并应用高密度脑电图(EEG)通过事件相关电位来评估大脑激活的时间动态。我们发现,在支配个体中,在选择任务中快速做出反应与大约刺激呈现后 240 毫秒时大脑信号的显著放大有关。源成像分析确定,在高支配力参与者中,左侧脑岛和扣带、右侧下颞叶和右侧角回的活动更高。我们的研究结果表明,在选择情境中快速做出反应,无论社交情境如何,都是社会倾向的生物标志物。