Does a visual percept emerge to consciousness in a graded manner (i.e. evolving through increasing degrees of clarity), or according to a dichotomous, “all-or-none” pattern (i.e. abruptly transitioning from unawareness to awareness)? The level of processing hypothesis (LoP; B. Windey and A. Cleeremans, 2015) recently proposed a theoretical framework where the transition from unaware to aware visual experience is graded for low-level stimulus representations (i.e. stimulus “energy” or “feature” levels) whereas it is dichotomous for high-level (i.e. the perception of “letters”, “words” or “meaning”) stimulus perception. Here, we will critically review current behavioral and brain-based evidence on the LoP hypothesis and discuss potential challenges (such as differences in LoP conceptualizations, awareness scale related issues, attentional confounds and divergences on experimental factors or statistical analyses) which might be of use for future research within the field. Overall, the LoP hypothesis is a recent and promising proposal that attempts to integrate divergent evidence on the graded vs. dichotomous emergence of awareness debate. Whereas current evidence validates some of the assumptions proposed by the LoP account, there is still much work to do on both methodological and experimental levels. Future neuroimaging studies might help to disentangle the current complex pattern of results found in LoP studies and, importantly, shed some light on the ongoing debate about the search for the Neural Correlates of Consciousness (NCC).

视觉知觉是以分级方式（即通过逐渐增加的清晰度演变），还是按照二分法、“全有或无”模式（即突然从无意识过渡到有意识）出现在意识中？该处理假设的水平（LoP；B. Windey 和 A. Cleeremans，2015）最近提出了一个理论框架，其中从无意识到有意识的视觉体验的过渡是针对低级刺激表示（即刺激“能量”或“特征”级别）进行分级的，而它是高层次（即“字母”、“单词”或“意义”的感知）刺激感知的二分法。在这里，我们将批判性地审查关于 LoP 假设的当前行为和基于大脑的证据，并讨论可能有用的潜在挑战（例如 LoP 概念化的差异、意识量表相关问题、注意力混淆和实验因素或统计分析的分歧）用于该领域的未来研究。总体而言，LoP 假设是最近提出的一项很有前途的提议，它试图整合分级与分级的不同证据。意识辩论的二分法出现。尽管目前的证据证实了 LoP 帐户提出的一些假设，但在方法论和实验水平上仍有许多工作要做。未来的神经影像学研究可能有助于解开当前在 LoP 研究中发现的复杂结果模式，更重要的是，可以阐明有关寻找意识神经相关性 (NCC) 的正在进行的辩论。