Graduate School of Education, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan; Japan Society for the Promotion of Science, Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan; Center of Baby Science, Doshisha University, 4-1-1 Kizugawadai, Kizugawashi, Kyoto, 619-0225, Japan.
Graduate School of Education, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
Neuropsychologia. 2021 Apr 16;154:107787. doi: 10.1016/j.neuropsychologia.2021.107787. Epub 2021 Feb 9.
Preferring fair resource distribution reflects human cooperative nature, but its neural correlates in young children are not well known. We investigated the neural mechanism of egalitarian resource sharing in five-to six-year-old children to examine the possibility that early egalitarianism requires behavioral control to inhibit selfish impulses. In Study 1, children participated in a behavioral control task in which they either needed or did not need to inhibit their impulsive behavioral responses in order to quickly press a key. They subsequently allocated their resources to strangers by choosing a 2:2, 3:1, or 4:0 distribution. The activation of the dorsolateral prefrontal (dlpfc) regions was recorded by functional near-infrared spectroscopy measurements. We found that dlpfc regions were activated during cognitive tasks involving behavioral control and also during the equal, but not the more selfish, allocations. There was no difference among these allocations. The results did not show evidence of an ego depletion effect on children's sharing behavior, which predicts that children will share less after their behavioral control is taxed in a cognitive task (i.e., their self-control resource depleted). Study 2 showed no activation of the dlpfc regions during third-party equal allocations in which there was no conflict between fairness and self-interest in the distribution of resources. Overall, we showed that costly equal sharing in young children relates to the activation of dlpfc regions. These results suggest that costly equal allocation has a common neural basis with behavioral control in five-to six-year-old children, implying that early egalitarian sharing requires dealing with conflicts between maximizing self-interest and following moral norms.
偏好公平的资源分配反映了人类的合作本性，但在幼儿中，其神经相关性尚不清楚。我们研究了五到六岁儿童平等分配资源的神经机制，以检验早期平等主义是否需要行为控制来抑制自私冲动的可能性。在研究 1 中，儿童参与了一项行为控制任务，在该任务中，他们要么需要要么不需要抑制冲动的行为反应，以便快速按下一个键。然后，他们通过选择 2:2、3:1 或 4:0 的分配来为陌生人分配资源。通过功能近红外光谱测量记录背外侧前额叶（dlpfc）区域的激活。我们发现，dlpfc 区域在涉及行为控制的认知任务中以及在平等但不是更自私的分配中被激活。这些分配之间没有差异。结果没有显示出儿童分享行为的自我损耗效应的证据，这表明儿童在认知任务中（即他们的自我控制资源耗尽）进行行为控制后，分享会减少。研究 2 表明，在第三方平等分配中，dlpfc 区域没有被激活，在资源分配中公平与自身利益之间没有冲突。总体而言，我们表明，年幼儿童的高成本平等分配与 dLPFC 区域的激活有关。这些结果表明，在五到六岁的儿童中，高成本平等分配与行为控制具有共同的神经基础，这意味着早期平等的分享需要处理最大化自身利益和遵循道德规范之间的冲突。
