Jimenez Courtney A, Meyer Meghan L
Department of Psychology, Columbia University, New York, NY 10027.
Proc Natl Acad Sci U S A. 2024 Mar 19;121(12):e2309232121. doi: 10.1073/pnas.2309232121. Epub 2024 Mar 11.
Sociality is a defining feature of the human experience: We rely on others to ensure survival and cooperate in complex social networks to thrive. Are there brain mechanisms that help ensure we quickly learn about our social world to optimally navigate it? We tested whether portions of the brain's default network engage "by default" to quickly prioritize social learning during the memory consolidation process. To test this possibility, participants underwent functional MRI (fMRI) while viewing scenes from the documentary film, . This film shows footage of real people and places from around the world. We normed the footage to select scenes that differed along the dimension of sociality, while matched on valence, arousal, interestingness, and familiarity. During fMRI, participants watched the "social" and "nonsocial" scenes, completed a rest scan, and a surprise recognition memory test. Participants showed superior social (vs. nonsocial) memory performance, and the social memory advantage was associated with neural pattern reinstatement during rest in the dorsomedial prefrontal cortex (DMPFC), a key node of the default network. Moreover, it was during early rest that DMPFC social pattern reinstatement was greatest and predicted subsequent social memory performance most strongly, consistent with the "prioritization" account. Results simultaneously update 1) theories of memory consolidation, which have not addressed how social information may be prioritized in the learning process, and 2) understanding of default network function, which remains to be fully characterized. More broadly, the results underscore the inherent human drive to understand our vastly social world.
我们依靠他人来确保生存，并在复杂的社会网络中合作以蓬勃发展。是否存在有助于确保我们快速了解社会世界以最佳方式驾驭它的大脑机制？我们测试了大脑默认网络的某些部分在记忆巩固过程中是否“默认”参与，以便快速对社会学习进行优先排序。为了测试这种可能性，参与者在观看纪录片《》中的场景时接受了功能磁共振成像（fMRI）检查。这部电影展示了来自世界各地的真实人物和地点的镜头。我们对这些镜头进行了规范，以选择在社会性维度上有所不同的场景，同时在效价、唤醒度、趣味性和熟悉度方面进行匹配。在功能磁共振成像期间，参与者观看了“社会”和“非社会”场景，完成了一次静息扫描，以及一次惊喜识别记忆测试。参与者表现出卓越的社会（相对于非社会）记忆表现，并且社会记忆优势与默认网络的关键节点背内侧前额叶皮层（DMPFC）在静息期间的神经模式恢复有关。此外，正是在早期静息期间，DMPFC的社会模式恢复最为显著，并且对随后的社会记忆表现预测最强，这与“优先排序”观点一致。研究结果同时更新了1）记忆巩固理论，该理论尚未涉及社会信息在学习过程中如何被优先排序的问题，以及2）对默认网络功能的理解，其功能仍有待全面描述。更广泛地说，这些结果强调了人类理解我们广阔社会世界的内在驱动力。
