Collerton Daniel, Tsuda Ichiro, Nara Shigetoshi
Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
AIT Center, Sapporo City University, Sapporo 005-0864, Japan.
Entropy (Basel). 2024 Jun 28;26(7):557. doi: 10.3390/e26070557.
Understandings of how visual hallucinations appear have been highly influenced by generative approaches, in particular Friston's Active Inference conceptualization. Their core proposition is that these phenomena occur when hallucinatory expectations outweigh actual sensory data. This imbalance occurs as the brain seeks to minimize informational free energy, a measure of the distance between predicted and actual sensory data in a stationary open system. We review this approach in the light of old and new information on the role of environmental factors in episodic hallucinations. In particular, we highlight the possible relationship of specific visual triggers to the onset and offset of some episodes. We use an analogy from phase transitions in physics to explore factors which might account for intermittent shifts between veridical and hallucinatory vision. In these triggered forms of hallucinations, we suggest that there is a transient disturbance in the normal one-to-one correspondence between a real object and the counterpart perception such that this correspondence becomes between the real object and a hallucination. Generative models propose that a lack of information transfer from the environment to the brain is one of the key features of hallucinations. In contrast, we submit that specific information transfer is required at onset and offset in these cases. We propose that this transient one-to-one correspondence between environment and hallucination is mediated more by aberrant discriminative than by generative inference. Discriminative inference can be conceptualized as a process for maximizing shared information between the environment and perception within a self-organizing nonstationary system. We suggest that generative inference plays the greater role in established hallucinations and in the persistence of individual hallucinatory episodes. We further explore whether thermodynamic free energy may be an additional factor in why hallucinations are temporary. Future empirical research could productively concentrate on three areas. Firstly, subjective perceptual changes and parallel variations in brain function during specific transitions between veridical and hallucinatory vision to inform models of how episodes occur. Secondly, systematic investigation of the links between environment and hallucination episodes to probe the role of information transfer in triggering transitions between veridical and hallucinatory vision. Finally, changes in hallucinatory episodes over time to elucidate the role of learning on phenomenology. These empirical data will allow the potential roles of different forms of inference in the stages of hallucinatory episodes to be elucidated.
对视觉幻觉如何出现的理解深受生成方法的影响，尤其是弗里斯顿的主动推理概念化。其核心观点是，当幻觉预期超过实际感官数据时，这些现象就会发生。这种失衡的出现是因为大脑试图将信息自由能降至最低，信息自由能是衡量静止开放系统中预测感官数据与实际感官数据之间距离的一种度量。我们根据关于环境因素在发作性幻觉中作用的新旧信息来审视这种方法。特别是，我们强调特定视觉触发因素与某些发作的起始和终止之间可能存在的关系。我们用物理学中相变的类比来探索可能导致真实视觉与幻觉视觉之间间歇性转换的因素。在这些由触发引起的幻觉形式中，我们认为在真实物体与相应感知之间正常的一一对应关系存在短暂干扰，以至于这种对应关系变成了真实物体与幻觉之间的对应关系。生成模型提出，从环境到大脑的信息传递不足是幻觉的关键特征之一。相比之下，我们认为在这些情况下，起始和终止时需要特定的信息传递。我们提出，环境与幻觉之间这种短暂的一一对应关系更多是由异常的辨别性推理而非生成性推理介导的。辨别性推理可以被概念化为在自组织非平稳系统中最大化环境与感知之间共享信息的过程。我们认为生成性推理在既定幻觉和个体幻觉发作的持续过程中发挥着更大作用。我们进一步探讨热力学自由能是否可能是幻觉为何是暂时的另一个因素。未来的实证研究可以富有成效地集中在三个领域。首先，在真实视觉与幻觉视觉之间的特定转换过程中，主观感知变化以及大脑功能的平行变化，以完善关于发作如何发生的模型。其次，系统研究环境与幻觉发作之间的联系，以探究信息传递在触发真实视觉与幻觉视觉之间转换中的作用。最后，随着时间推移研究幻觉发作的变化，以阐明学习对现象学的作用。这些实证数据将有助于阐明不同形式的推理在幻觉发作各阶段的潜在作用。
