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）更新训练可提升受试者在字母记忆标准任务中的表现，且能迁移至未经过训练的n-back任务，并在标准任务执行期间增强纹状体多巴胺（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。我们采用放射性配体雷氯必利开展了4次正电子发射断层扫描（positron emission tomography，PET）：其中2次在5周的更新训练前，分别评估了字母记忆任务与n-back任务下的多巴胺D2受体结合情况；训练结束后，又重复完成了相同的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提升；(b) 训练后受试者执行字母记忆任务时，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) 干预后受试者执行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。