The physical basis of consciousness remains one of the most elusive concepts in current science. One influential conjecture is that consciousness is to do with some form of causality, measurable through information. The integrated information theory of consciousness (IIT) proposes that conscious experience, filled with rich and specific content, corresponds directly to a hierarchically organised, irreducible pattern of causal interactions; i.e. an integrated informational structure among elements of a system. Here, we tested this conjecture in a simple biological system (fruit flies), estimating the information structure of the system during wakefulness and general anesthesia. Consistent with this conjecture, we found that integrated interactions among populations of neurons during wakefulness collapsed to isolated clusters of interactions during anesthesia. We used classification analysis to quantify the accuracy of discrimination between wakeful and anesthetised states, and found that informational structures inferred conscious states with greater accuracy than a scalar summary of the structure, a measure which is generally championed as the main measure of IIT. In stark contrast to a view which assumes feedforward architecture for insect brains, especially fly visual systems, we found rich information structures, which cannot arise from purely feedforward systems, occurred across the fly brain. Further, these information structures collapsed uniformly across the brain during anesthesia. Our results speak to the potential utility of the novel concept of an 'informational structure' as a measure for level of consciousness, above and beyond simple scalar values.

中文翻译：

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果蝇的综合信息结构因麻醉而失去意识唤醒而崩溃

意识的物理基础仍然是当前科学中最难以捉摸的概念之一。一个有影响力的推测是，意识与某种因果关系有关，可以通过信息来衡量。意识综合信息理论（IIT）提出，充满丰富而具体的内容的意识体验直接对应于因果互动的层次结构化，不可简化的模式。即系统元素之间的集成信息结构。在这里，我们在一个简单的生物系统（果蝇）中测试了这个猜想，估计了清醒和全身麻醉期间系统的信息结构。与此猜想一致，我们发现清醒时神经元群体之间的整合相互作用崩溃为麻醉过程中孤立的相互作用簇。我们使用分类分析来量化清醒状态和麻醉状态之间的区分准确度，发现信息结构比结构的标量摘要更准确地推断出意识状态，该方法通常被称为IIT的主要指标。与假定昆虫大脑（特别是飞行视觉系统）的前馈结构的观点形成鲜明对比的是，我们发现飞大脑中出现了丰富的信息结构，这些信息结构不能纯粹由前馈系统产生。此外，这些信息结构在麻醉期间会在整个大脑中均匀塌陷。