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.

既往研究表明，工作记忆（working-memory，WM）更新训练可提升被试在字母记忆标准任务上的表现，且能迁移至未经过训练的n-back任务，同时可增强标准任务执行过程中的纹状体多巴胺（striatal dopamine，DA）活性。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。研究共开展4次使用放射性配体雷氯必利（radioligand raclopride）的正电子发射断层扫描（positron emission tomography，PET）：其中2次在5周更新训练前评估了多巴胺D2受体结合（DAD2 binding）情况（对应字母记忆任务与n-back任务），训练后又完成了相同的2次扫描。核心研究结果包括：(a) 字母记忆标准任务中出现显著的训练相关行为学获益；(b) 训练后字母记忆任务执行期间的纹状体多巴胺D2受体结合潜能发生改变，提示训练诱导了多巴胺释放增加；(c) 干预后n-back迁移任务执行期间的纹状体多巴胺活性同样升高，但未伴随相应的行为学迁移效应。值得注意的是，迁移任务中训练相关的多巴胺改变并未伴随行为学迁移，这表明多巴胺释放增加可能是行为学迁移发生的必要而非充分条件。