Aging Research Center, Karolinska Institute, Stockholm, Sweden.
Department of Psychology, Åbo Akademi University, Turku, Finland.
Sci Rep. 2017 Aug 2;7(1):7160. doi: 10.1038/s41598-017-07577-y.
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.
先前的研究表明，工作记忆（WM）更新训练可提高字母记忆标准任务的表现，可转移到未训练的 n 回任务，并增加标准任务期间纹状体多巴胺（DA）的活性。在这里，我们试图通过检查转移的神经化学相关性来复制和扩展这些发现。使用放射性配体[raclopride]进行了 4 次正电子发射断层扫描（PET）。其中两项评估了 DAD2 结合（字母记忆；n 回）在 5 周的更新训练之前，并且对相同的两项扫描进行了训练后评估。主要发现包括：（a）字母记忆标准任务中表现出明显的训练相关行为增益；（b）训练后字母记忆过程中纹状体 DAD2 结合潜能发生改变，表明 DA 释放增加；（c）干预后 n 回转移任务期间纹状体 DA 活性增加，但无伴随的行为转移。在转移任务中，与训练相关的 DA 改变不伴有行为转移的事实表明，增加的 DA 释放可能是行为转移发生的必要但非充分条件。
