Abstract It has been theorized that cortical feed-forward and recurrent neural activity support unconscious and conscious cognitive processes, respectively. Here we causally tested this proposition by applying event-related transcranial magnetic stimulation (TMS) at early and late times relative to visual stimuli, together with a pulse designed to suppress conscious detection. Consistent with pre-registered hypotheses, early TMS affected residual, reportedly ‘unseen’ capacity. However, conscious perception also appeared critically dependent upon feed-forward processing to a greater extent than the later recurrent phase. Additional exploratory analyses suggested that these early effects dissociated from top-down criterion measures, which were most affected by later TMS. These findings are inconsistent with a simple dichotomy where feed-forward and recurrent processes correspond to unconscious and conscious mechanisms. Instead, different components of awareness may correspond to different phases of cortical dynamics in which initial processing is broadly perceptual whereas later recurrent processing might relate to decision to report.

中文翻译：

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前馈和循环加工的因果操作差异影响意识测验

摘要从理论上讲，皮层前馈和循环神经活动分别支持无意识和有意识的认知过程。在这里，我们通过在相对于视觉刺激的早期和晚期应用事件相关的经颅磁刺激（TMS）以及旨在抑制有意识检测的脉冲，来对这一主张进行因果检验。与预先注册的假设一致，早期的TMS影响了残留的，据说是“看不见的”能力。但是，自觉感知还比下一个循环阶段更严重地依赖前馈处理。进一步的探索性分析表明，这些早期影响与自上而下的标准测量方法无关，后者受后期TMS的影响最大。这些发现与简单的二分法不一致，在二分法中，前馈和循环过程对应于无意识和有意识的机制。取而代之的是，意识的不同组成部分可能对应于皮质动力学的不同阶段，在该阶段中，初始处理在很大程度上是感知性的，而后来的循环处理可能与报告决策有关。