School of Psychology and Bangor Imaging Unit, Bangor University, Bangor, Wales LL57 2AS, UK; Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK.
Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK; Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK.
Neuron. 2019 Mar 20;101(6):1166-1180.e3. doi: 10.1016/j.neuron.2019.01.018. Epub 2019 Feb 7.
Fluent retrieval and execution of movement sequences is essential for daily activities, but the neural mechanisms underlying sequence planning remain elusive. Here participants learned finger press sequences with different orders and timings and reproduced them in a magneto-encephalography (MEG) scanner. We classified the MEG patterns for each press in the sequence and examined pattern dynamics during preparation and production. Our results demonstrate the "competitive queuing" (CQ) of upcoming action representations, extending previous computational and non-human primate recording studies to non-invasive measures in humans. In addition, we show that CQ reflects an ordinal template that generalizes across specific motor actions at each position. Finally, we demonstrate that CQ predicts participants' production accuracy and originates from parahippocampal and cerebellar sources. These results suggest that the brain learns and controls multiple sequences by flexibly combining representations of specific actions and interval timing with high-level, parallel representations of sequence position.
流畅地检索和执行运动序列对于日常活动至关重要，但序列规划的神经机制仍难以捉摸。在这里，参与者学习了具有不同顺序和时间的手指按压序列，并在磁共振脑磁图（MEG）扫描仪中复制了这些序列。我们对序列中的每个按压进行了 MEG 模式分类，并在准备和生产过程中检查了模式动态。我们的结果表明，即将到来的动作表示存在“竞争排队”（CQ），这将先前的计算和非人类灵长类动物记录研究扩展到了人类的非侵入性测量中。此外，我们还表明，CQ 反映了一种有序模板，该模板在每个位置的特定运动动作上具有通用性。最后，我们证明 CQ 可以预测参与者的生产准确性，并且源自海马旁回和小脑的源。这些结果表明，大脑通过灵活地将特定动作和时间间隔的表示与序列位置的高级并行表示相结合，来学习和控制多个序列。
