Yang Yi, Ludwig Rita M, Wyngaarden James B, Dwamena Derrick, Hackett Katherine, Giovannetti Tania, Fareri Dominic S, Smith David V
Temple University, Philadelphia, USA.
University of Pennsylvania, Philadelphia, USA.
bioRxiv. 2025 Aug 18:2025.08.13.670194. doi: 10.1101/2025.08.13.670194.
The ability to navigate diverse social contexts, such as interacting with different individuals, is crucial across the lifespan and has implications for fraud susceptibility. However, the neural mechanisms supporting social decisions in older adults within varied social contexts remain largely unknown. This study investigated how age and partner similarity modulate neural activation and network connectivity during fairness-related decision making and whether individual differences in behavioral sensitivity to fairness norm violations correlate with neural activities.
Younger (18-35) and older (65-80) adults underwent fMRI while playing an ultimatum game with ostensible partners of a similar or dissimilar age. We used regression to model choice behavior and whole-brain fMRI analyses to examine functional activation and connectivity of the Default Mode (DMN) and Executive Control (ECN) networks.
Behaviorally, choices did not differ by age, partner similarity, or their interactions. In contrast, neuroimaging revealed interactions between age, partner similarity, and individual sensitivity to norm violation. Younger adults exhibited positive DMN-anterior cingulate connectivity when interacting with a similar-aged partner, whereas older adults showed a negative connectivity. Furthermore, younger adults demonstrated a negative correlation between their sensitivity to norm violation and the partner-identity effect in ECN-medial prefrontal cortex connectivity, whereas older adults showed a positive correlation.
Our findings indicate a brain-behavior dissociation where different neural mechanisms support similar behavioral outcomes across age groups. These opposing patterns of neural responses suggest age-related functional reorganizations, which may represent compensatory strategies that enable older adults to preserve behaviors similar to that of their younger counterparts.
在整个生命周期中，驾驭不同社会情境的能力，例如与不同个体互动，至关重要，且对欺诈易感性有影响。然而，支持老年人在不同社会情境下做出社会决策的神经机制在很大程度上仍不为人知。本研究调查了年龄和伙伴相似性如何在与公平相关的决策过程中调节神经激活和网络连通性，以及对公平规范违反行为的行为敏感性的个体差异是否与神经活动相关。
年轻（18 - 35岁）和年长（65 - 80岁）成年人在与年龄相似或不同的表面伙伴玩最后通牒游戏时接受功能磁共振成像（fMRI）检查。我们使用回归模型来分析选择行为，并通过全脑fMRI分析来检查默认模式网络（DMN）和执行控制网络（ECN）的功能激活和连通性。
在行为上，选择在年龄、伙伴相似性或它们的交互作用方面没有差异。相比之下，神经影像学显示年龄、伙伴相似性和个体对规范违反的敏感性之间存在交互作用。年轻成年人在与年龄相似的伙伴互动时，默认模式网络与前扣带回之间表现出正连通性，而年长成年人则表现出负连通性。此外，年轻成年人对规范违反的敏感性与执行控制网络 - 内侧前额叶皮质连通性中的伙伴身份效应之间呈负相关，而年长成年人则呈正相关。
我们的研究结果表明存在脑 - 行为分离，即不同的神经机制在不同年龄组中支持相似的行为结果。这些相反的神经反应模式表明与年龄相关的功能重组，这可能代表了补偿策略，使年长成年人能够保持与年轻同龄人相似的行为。
