他们对志愿者的视觉任务进行了训练，并在随后的睡眠过程中测量了早期视觉区域的兴奋性和抑制性（E / I）平衡，以此作为可塑性的指标。不管是否进行睡前学习，在NREM睡眠期间，E / I平衡都会增加，但与睡前相对于睡后学习获益有关。相反，在REM睡眠期间，E / I平衡下降，但仅在睡前学习后下降，并且该下降与睡前学习的稳定有关。
Title: Complementary contributions of non-REM and REM sleep to visual learning
Author: Masako Tamaki, Zhiyan Wang, Tyler Barnes-Diana, DeeAnn Guo, Aaron V. Berard, Edward Walsh, Takeo Watanabe, Yuka Sasaki
Abstract: Sleep is beneficial for learning. However, it remains unclear whether learning is facilitated by non-rapid eye movement (NREM) sleep or by REM sleep, whether it results from plasticity increases or stabilization, and whether facilitation results from learning-specific processing. Here, we trained volunteers on a visual task and measured the excitatory and inhibitory (E/I) balance in early visual areas during subsequent sleep as an index of plasticity. The E/I balance increased during NREM sleep irrespective of whether pre-sleep learning occurred, but it was associated with post-sleep performance gains relative to pre-sleep performance. In contrast, the E/I balance decreased during REM sleep but only after pre-sleep training, and the decrease was associated with stabilization of pre-sleep learning. These findings indicate that NREM sleep promotes plasticity, leading to performance gains independent of learning, while REM sleep decreases plasticity to stabilize learning in a learning-specific manner. Tamaki et al. measured MRS changes in sleeping humans trained on a visual task. During NREM sleep, learning gains were associated with enhanced visual cortical plasticity that was also seen independent of learning. REM sleep stabilized plasticity only after pre-sleep learning.