The evolutionary and neural underpinnings of human prosociality are still being identified. A growing body of evidence suggests that some species find the sight of another individual receiving a reward reinforcing, called vicarious reinforcement, and that this capacity is supported by a network of brain areas including the anterior cingulate cortex (ACC) and the amygdala. At the same time, analyses of autonomic arousal have been increasingly used to contextualize and guide neural research, especially for studies of reward processing. Here, we characterized the autonomic pupil response of eight monkeys across two laboratories in two different versions of a vicarious reinforcement paradigm. Monkeys were cued as to whether an upcoming reward would be delivered to them, another monkey, or nobody and could accept or decline the offer. As expected, all monkeys in both laboratories showed a marked preference for juice to the self, together with a reliable prosocial preference for juice to a social partner compared to juice to nobody. However, contrary to our expectations, we found that pupils were widest in anticipation of juice to the self, moderately sized in anticipation of juice to nobody, and narrowest in anticipation of juice to a social partner. This effect was seen across both laboratories and regardless of specific task parameters. The seemingly paradoxical pupil effect can be explained by a model in which pupil size tracks outcome salience, prosocial tendencies track outcome valence, and the relation between salience and valence is U-shaped. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

中文翻译：

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自主唤醒跟踪猴子做出社会决策的结果显着性而不是效价。


人类亲社会性的进化和神经基础仍在研究中。越来越多的证据表明，一些物种发现另一个个体收到奖励强化，称为替代强化，并且这种能力得到了包括前扣带皮层（ACC）和杏仁核在内的大脑区域网络的支持。与此同时，自主神经唤醒的分析越来越多地用于情境化和指导神经研究，特别是奖励处理的研究。在这里，我们用两个不同版本的替代强化范例描述了两个实验室中八只猴子的自主瞳孔反应。猴子被提示即将到来的奖励是否会交付给他们、另一只猴子或任何人，并且可以接受或拒绝该提议。正如预期的那样，两个实验室中的所有猴子都对自己的果汁表现出明显的偏好，并且与对任何人的果汁相比，对社会伙伴的果汁表现出可靠的亲社会偏好。然而，与我们的预期相反，我们发现学生对自己喝果汁的预期最大，对没有人喝果汁的预期中等，对社会伙伴喝果汁的预期最窄。无论具体任务参数如何，两个实验室都可以看到这种效果。看似矛盾的瞳孔效应可以用一个模型来解释，其中瞳孔大小跟踪结果显着性，亲社会倾向跟踪结果效价，显着性和效价之间的关系呈 U 形。 （PsycInfo 数据库记录 (c) 2021 APA，保留所有权利）。