The motivation to approach or avoid incentives can change during adolescence. Advances in neuroimaging allow researchers to characterize specific brain circuits that underlie these developmental changes. Whereas activity in the nucleus accumbens (NAcc) can predict approach toward incentive gain, activity in anterior insula (AIns) is associated with avoidance of incentive loss. Recent research characterized the structural white-matter tract connecting the two brain regions, but the tract has neither been characterized in adolescence nor linked to functional activity during incentive anticipation. In this study, we collected diffusion MRI and characterized the tract connecting the AIns to the NAcc for the first time in early adolescents. We then measured NAcc functional activity during a monetary incentive delay task and found that structural coherence of the AIns-NAcc tract is correlated with decreased functional activity at the NAcc terminal of the tract during anticipation of no incentives. In adolescents who completed an assessment 2 years later, we found that AIns-NAcc tract coherence could predict greater future self-reported motivation, and that NAcc functional activity could statistically mediate this association. Together, the findings establish links from brain structure to function to future motivation and provide targets to study the reciprocal development of brain structure and function.

接近或避免激励的动机可能会在青春期发生变化。神经影像学的进步使研究人员能够表征这些发育变化背后的特定大脑回路。伏隔核 (NAcc) 的活动可以预测获得激励的途径，而前脑岛 (AIns) 的活动与避免激励损失有关。最近的研究表征了连接两个大脑区域的结构性白质束，但该束既没有在青春期表征，也没有与激励预期期间的功能活动相关联。在这项研究中，我们收集了弥散 MRI 并在早期青少年中首次表征了将 AIns 连接到 NAcc 的通道。然后，我们在货币激励延迟任务期间测量了 NAcc 功能活动，发现 AIns-NAcc 道的结构连贯性与在没有激励预期期间该道 NAcc 末端的功能活动减少有关。在 2 年后完成评估的青少年中，我们发现 AIns-NAcc 道连贯性可以预测更大的未来自我报告动机，并且 NAcc 功能活动可以在统计上调节这种关联。总之，这些发现建立了从大脑结构到功能到未来动机的联系，并为研究大脑结构和功能的相互发展提供了目标。在 2 年后完成评估的青少年中，我们发现 AIns-NAcc 道连贯性可以预测更大的未来自我报告动机，并且 NAcc 功能活动可以在统计上调节这种关联。总之，这些发现建立了从大脑结构到功能到未来动机的联系，并为研究大脑结构和功能的相互发展提供了目标。在 2 年后完成评估的青少年中，我们发现 AIns-NAcc 道连贯性可以预测更大的未来自我报告动机，并且 NAcc 功能活动可以在统计上调节这种关联。总之，这些发现建立了从大脑结构到功能到未来动机的联系，并为研究大脑结构和功能的相互发展提供了目标。