"Perception as Controlled Hallucination": From Neurocentrism to Action-Perception Coupling

The Predictive Processing (PP) model outlines a "top-down" picture of mental operations, proposing the existence of bidirectional neural information flows that converge and match to generate prediction errors, with the brain consistently aiming to minimize these errors. While the predictive processing paradigm is comprehensive, this article focuses specifically on a counterintuitive proposition within PP—"perception as controlled hallucination." In contemporary discussions, the predictive processing model has developed into two main approaches: the neurocentric approach, led by Hohwy, and the action-perception coupling approach, championed by Clark. This paper aims to examine the justifications of the "perception as controlled hallucination" proposition within these two distinct PP theoretical approaches, discuss their divergences, and further compare their strengths and weaknesses. The study finds that the neurocentric justification, due to its internalist tendencies, faces skeptical challenges and issues of insufficient justification. In contrast, the action-perception coupling approach to predictive processing, which emphasizes embodiment, adopts an externalist stance that can uphold the everyday justificatory status of perception. Moreover, when perceptual experience serves as a channel coupling the mind and the world, the process reliability it entails is absent in hallucinatory experiences. Thus, while acknowledging the similarity between perception and hallucination, this approach successfully substantiates the argument that perception is "controlled hallucination."