Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands.
J Neurosci. 2012 Feb 8;32(6):1981-8. doi: 10.1523/JNEUROSCI.3712-11.2011.
Practice-induced improvements in skilled performance reflect "offline " consolidation processes extending beyond daily training sessions. According to visual learning theories, an early, fast learning phase driven by high-level areas is followed by a late, asymptotic learning phase driven by low-level, retinotopic areas when higher resolution is required. Thus, low-level areas would not contribute to learning and offline consolidation until late learning. Recent studies have challenged this notion, demonstrating modified responses to trained stimuli in primary visual cortex (V1) and offline activity after very limited training. However, the behavioral relevance of modified V1 activity for offline consolidation of visual skill memory in V1 after early training sessions remains unclear. Here, we used neuronavigated transcranial magnetic stimulation (TMS) directed to a trained retinotopic V1 location to test for behaviorally relevant consolidation in human low-level visual cortex. Applying TMS to the trained V1 location within 45 min of the first or second training session strongly interfered with learning, as measured by impaired performance the next day. The interference was conditional on task context and occurred only when training in the location targeted by TMS was followed by training in a second location before TMS. In this condition, high-level areas may become coupled to the second location and uncoupled from the previously trained low-level representation, thereby rendering consolidation vulnerable to interference. Our data show that, during the earliest phases of skill learning in the lowest-level visual areas, a behaviorally relevant form of consolidation exists of which the robustness is controlled by high-level, contextual factors.
技能表现的练习诱导改善反映了“离线”巩固过程，这些过程超出了日常训练课程的范围。根据视觉学习理论，在需要更高分辨率时，由高级区域驱动的早期、快速学习阶段会被由低级、视网膜区域驱动的晚期、渐近学习阶段所取代。因此，在晚期学习之前，低级区域不会对学习和离线巩固做出贡献。最近的研究挑战了这一观点，证明了在初级视觉皮层（V1）中对训练刺激的反应发生了改变，并且在非常有限的训练后离线活动也发生了改变。然而，V1 中早期训练后 V1 中视觉技能记忆的离线巩固的 V1 活动的行为相关性仍然不清楚。在这里，我们使用神经导航经颅磁刺激（TMS）作用于经过训练的视网膜 V1 位置，以测试人类低级视觉皮层中与行为相关的巩固作用。在第一次或第二次训练后的 45 分钟内，将 TMS 应用于经过训练的 V1 位置会强烈干扰学习，表现为第二天的表现受损。这种干扰取决于任务上下文，并且仅在 TMS 靶向的训练位置之后在 TMS 之前在第二个位置进行训练时才会发生。在这种情况下，高级区域可能与第二个位置耦合，与之前训练的低级表示解耦，从而使巩固容易受到干扰。我们的数据表明，在最低级别的视觉区域的技能学习的最早阶段，存在一种与行为相关的巩固形式，其稳健性受到高级、上下文因素的控制。
