Several studies have shown that the benefits of working memory (WM) training can be attributed to functional and structural neural changes in the underlying neural substrate. In the current study, we investigated whether the functional connectivity of the brain at rest in the default mode network (DMN) changes with WM training. We varied the complexity of the training intervention so, that half of the participants attended dual n-back training whereas the other half attended single n-back training. This way we could assess the effects of different training task parameters on possible connectivity changes. After 16 training sessions, the dual n-back training group showed improved performance accompanied by increased functional connectivity of the ventral DMN in the right inferior frontal gyrus, which correlated with improvements in WM. We also observed decreased functional connectivity in the left superior parietal cortex in this group. The single n-back training group did not show significant training-related changes. These results show that a demanding short-term WM training intervention can alter the default state of the brain.

多项研究表明，工作记忆（WM）训练的好处可归因于基础神经基质中的功能性和结构性神经变化。在当前的研究中，我们调查了默认模式网络（DMN）中静止状态下大脑的功能连通性是否随着WM训练而改变。我们改变了培训干预的复杂性，因此，一半的参与者参加了两次n-back训练，而另一半参加了单个n-back训练。这样，我们可以评估不同训练任务参数对可能的连接性变化的影响。经过16次训练后，双n背部训练组显示出性能改善，同时右侧下额回的腹侧DMN的功能连接性增加，这与WM的改善相关。我们还观察到该组左上顶叶皮质的功能连接性降低。单个n背部训练组未显示与训练相关的重大变化。这些结果表明，要求苛刻的短期WM训练干预可以改变大脑的默认状态。