The orbitofrontal cortex (OFC) is a key brain region involved in complex cognitive functions such as reward processing and decision making. Neuroimaging studies have reported unilateral OFC response to reward-related variables; however, those studies rarely discussed this observation. Nevertheless, some lesion studies suggest that the left and right OFC contribute differently to cognitive processes. We hypothesized that the OFC asymmetrical response to reward could reflect underlying hemispherical difference in OFC functional connectivity. Using resting-state and reward-related functional MRI data from humans and from rhesus macaques, we first identified an asymmetrical response of the lateral OFC to reward in both species. Crucially, the subregion showing the highest reward-related asymmetry (RRA) overlapped with the region showing the highest functional connectivity asymmetry (FCA). Furthermore, the two types of asymmetries were found to be significantly correlated across individuals. In both species, the right lateral OFC was more connected to the default mode network compared to the left lateral OFC. Altogether, our results suggest a functional specialization of the left and right lateral OFC in primates.

眶额皮质 (OFC) 是一个关键的大脑区域，涉及复杂的认知功能，如奖励处理和决策。神经影像学研究报告了对奖励相关变量的单侧 OFC 反应；然而，这些研究很少讨论这一观察结果。然而，一些病变研究表明左右 OFC 对认知过程的贡献不同。我们假设 OFC 对奖励的不对称反应可以反映 OFC 功能连接中潜在的半球差异。使用来自人类和恒河猴的静息状态和奖励相关的功能 MRI 数据，我们首先确定了两个物种的侧向 OFC 对奖励的不对称反应。至关重要的是，显示最高奖励相关不对称（RRA）的子区域与显示最高功能连接不对称（FCA）的区域重叠。此外，发现这两种类型的不对称在个体之间存在显着相关性。在这两个物种中，与左侧 OFC 相比，右侧 OFC 与默认模式网络的连接更多。总而言之，我们的结果表明灵长类动物左侧和右侧OFC的功能特化。