Powers Albert R, Kelley Megan, Corlett Philip R
Department of Psychiatry, Yale University.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2016 Sep;1(5):393-400. doi: 10.1016/j.bpsc.2016.04.003.
The problem of whether and how information is integrated across hierarchical brain networks embodies a fundamental tension in contemporary cognitive neuroscience, and by extension, cognitive neuropsychiatry. Indeed, the penetrability of perceptual processes in a 'top-down' manner by higher-level cognition-a natural extension of hierarchical models of perception-may contradict a strictly modular view of mental organization. Furthermore, some in the cognitive science community have challenged cognitive penetration as an unlikely, if not impossible, process. We review the evidence for and against top-down influences in perception, informed by a predictive coding model of perception and drawing heavily upon the literature of computational neuroimaging. We extend these findings to propose a way in which these processes may be altered in mental illness. We propose that hallucinations - perceptions without stimulus - can be understood as top-down effects on perception, mediated by inappropriate perceptual priors.
信息是否以及如何在分层脑网络中整合的问题体现了当代认知神经科学乃至认知神经精神病学中的一个基本矛盾。事实上，高级认知以“自上而下”的方式对感知过程的渗透性——这是感知分层模型的自然延伸——可能与心智组织的严格模块化观点相矛盾。此外，认知科学界的一些人对认知渗透性提出了质疑，认为这是一个即便并非不可能但也不太可能的过程。我们以感知的预测编码模型为依据，并大量借鉴计算神经成像文献，回顾了支持和反对感知中自上而下影响的证据。我们扩展这些发现，提出一种在精神疾病中这些过程可能被改变的方式。我们认为，幻觉——无刺激的感知——可以被理解为由不适当的感知先验介导的对感知的自上而下的影响。
