Du Yue, Prashad Shikha, Schoenbrun Ilana, Clark Jane E
Department of Kinesiology, University of MarylandCollege Park, MD, USA; Applied Mathematics and Statistics, and Scientific Computation Program, University of MarylandCollege Park, MD, USA.
Department of Kinesiology, University of MarylandCollege Park, MD, USA; Neuroscience and Cognitive Science Program, University of MarylandCollege Park, MD, USA.
Front Hum Neurosci. 2016 Mar 2;10:87. doi: 10.3389/fnhum.2016.00087. eCollection 2016.
It is well acknowledged that motor sequences can be learned quickly through online learning. Subsequently, the initial acquisition of a motor sequence is boosted or consolidated by offline learning. However, little is known whether offline learning can drive the fast learning of motor sequences (i.e., initial sequence learning in the first training session). To examine offline learning in the fast learning stage, we asked four groups of young adults to perform the serial reaction time (SRT) task with either a fixed or probabilistic sequence and with or without preliminary knowledge (PK) of the presence of a sequence. The sequence and PK were manipulated to emphasize either procedural (probabilistic sequence; no preliminary knowledge (NPK)) or declarative (fixed sequence; with PK) memory that were found to either facilitate or inhibit offline learning. In the SRT task, there were six learning blocks with a 2 min break between each consecutive block. Throughout the session, stimuli followed the same fixed or probabilistic pattern except in Block 5, in which stimuli appeared in a random order. We found that PK facilitated the learning of a fixed sequence, but not a probabilistic sequence. In addition to overall learning measured by the mean reaction time (RT), we examined the progressive changes in RT within and between blocks (i.e., online and offline learning, respectively). It was found that the two groups who performed the fixed sequence, regardless of PK, showed greater online learning than the other two groups who performed the probabilistic sequence. The groups who performed the probabilistic sequence, regardless of PK, did not display online learning, as indicated by a decline in performance within the learning blocks. However, they did demonstrate remarkably greater offline improvement in RT, which suggests that they are learning the probabilistic sequence offline. These results suggest that in the SRT task, the fast acquisition of a motor sequence is driven by concurrent online and offline learning. In addition, as the acquisition of a probabilistic sequence requires greater procedural memory compared to the acquisition of a fixed sequence, our results suggest that offline learning is more likely to take place in a procedural sequence learning task.
人们普遍认为，运动序列可以通过在线学习快速习得。随后，运动序列的初始习得会通过离线学习得到增强或巩固。然而，关于离线学习是否能推动运动序列的快速学习（即第一次训练 session 中的初始序列学习），我们知之甚少。为了研究快速学习阶段的离线学习，我们让四组年轻人执行序列反应时（SRT）任务，任务序列分为固定序列或概率序列，且被试对是否存在序列有或没有先验知识（PK）。通过操纵序列和 PK，以强调程序性（概率序列；无先验知识（NPK））或陈述性（固定序列；有 PK）记忆，发现这两种记忆分别促进或抑制离线学习。在 SRT 任务中，有六个学习块，每个连续块之间有 2 分钟的休息时间。在整个实验过程中，刺激遵循相同的固定或概率模式，但在第 5 块中除外，其中刺激以随机顺序出现。我们发现，PK 促进了固定序列的学习，但对概率序列没有促进作用。除了通过平均反应时（RT）衡量的总体学习外，我们还检查了块内和块间 RT 的渐进变化（即分别为在线学习和离线学习）。结果发现，执行固定序列的两组，无论是否有 PK，都比执行概率序列的另外两组表现出更大的在线学习。执行概率序列的两组，无论是否有 PK，在学习块内的表现下降表明他们没有显示出在线学习。然而，他们在 RT 上确实表现出明显更大的离线改善，这表明他们正在离线学习概率序列。这些结果表明，在 SRT 任务中，运动序列的快速习得是由并发的在线学习和离线学习驱动的。此外，由于与固定序列的习得相比，概率序列的习得需要更多的程序性记忆，我们的结果表明离线学习更有可能发生在程序性序列学习任务中。
