Data from: Increased dopamine release after working-memory updating training: neurochemical correlates of transfer

Previous work demonstrates that working-memory (WM) updating training results in improved performance on a letter-memory criterion task, transfers to an untrained n-back task, and increases striatal dopamine (DA) activity during the criterion task. Here, we sought to replicate and extend these findings by also examining neurochemical correlates of transfer. Four positron emission tomography (PET) scans using the radioligand raclopride were performed. Two of these assessed DAD2 binding (letter memory; n-back) before 5 weeks of updating training, and the same two scans were performed post training. Key findings were (a) pronounced training-related behavioral gains in the letter-memory criterion task, (b) altered striatal DAD2 binding potential after training during letter-memory performance, suggesting training-induced increases in DA release, and (c) increased striatal DA activity also during the n-back transfer task after the intervention, but no concomitant behavioral transfer. The fact that the training-related DA alterations during the transfer task were not accompanied by behavioral transfer suggests that increased DA release may be a necessary, but not sufficient, condition for behavioral transfer to occur.

过往研究证实，工作记忆（working-memory, WM）更新训练可提升个体在字母记忆标准任务中的表现，且能向未经过训练的n-back任务（n-back task）发生迁移，同时可增强标准任务执行过程中的纹状体多巴胺（dopamine, DA）活动。本研究旨在复现并拓展上述研究结论，同时考察迁移效应的神经化学关联。本研究共开展4次正电子发射断层扫描（positron emission tomography, PET），所用放射性配体为雷氯必利（raclopride）。其中2次扫描在5周的更新训练前完成，分别针对字母记忆任务与n-back任务评估DAD2结合情况，训练结束后又完成了相同的2次扫描。核心研究结果包括：(a) 字母记忆标准任务中出现了显著的训练相关行为学增益；(b) 训练后执行字母记忆任务时，纹状体DAD2结合电位发生改变，提示训练可诱导多巴胺释放增加；(c) 干预后执行n-back迁移任务时，纹状体多巴胺活动同样增强，但未伴随相应的行为学迁移效应。迁移任务中与训练相关的多巴胺改变并未伴随行为学迁移，这一结果提示，多巴胺释放增加或许是行为学迁移发生的必要而非充分条件。