Plebe Alessio
Department of Cognitive Science, Università degli Studi di Messina, v. Concezione 8, Messina, Italy.
Hist Philos Life Sci. 2018 Jun 15;40(3):40. doi: 10.1007/s40656-018-0205-2.
This paper addresses a fundamental line of research in neuroscience: the identification of a putative neural processing core of the cerebral cortex, often claimed to be "canonical". This "canonical" core would be shared by the entire cortex, and would explain why it is so powerful and diversified in tasks and functions, yet so uniform in architecture. The purpose of this paper is to analyze the search for canonical explanations over the past 40 years, discussing the theoretical frameworks informing this research. It will highlight a bias that, in my opinion, has limited the success of this research project, that of overlooking the dimension of cortical development. The earliest explanation of the cerebral cortex as canonical was attempted by David Marr, deriving putative cortical circuits from general mathematical laws, loosely following a deductive-nomological account. Although Marr's theory turned out to be incorrect, one of its merits was to have put the issue of cortical circuit development at the top of his agenda. This aspect has been largely neglected in much of the research on canonical models that has followed. Models proposed in the 1980s were conceived as mechanistic. They identified a small number of components that interacted as a basic circuit, with each component defined as a function. More recent models have been presented as idealized canonical computations, distinct from mechanistic explanations, due to the lack of identifiable cortical components. Currently, the entire enterprise of coming up with a single canonical explanation has been criticized as being misguided, and the premise of the uniformity of the cortex has been strongly challenged. This debate is analyzed here. The legacy of the canonical circuit concept is reflected in both positive and negative ways in recent large-scale brain projects, such as the Human Brain Project. One positive aspect is that these projects might achieve the aim of producing detailed simulations of cortical electrical activity, a negative one regards whether they will be able to find ways of simulating how circuits actually develop.
确定大脑皮层中一个假定的神经处理核心，该核心常被认为是“典型的”。这个“典型”核心将为整个皮层所共有，并能解释为何皮层在任务和功能方面如此强大且多样，但其结构却如此统一。本文旨在分析过去40年里对典型解释的探寻，讨论为该研究提供信息的理论框架。它将突出一种偏见，在我看来，这种偏见限制了这个研究项目的成功，即忽视了皮层发育的维度。最早将大脑皮层解释为典型的尝试是由大卫·马尔做出的，他从一般数学定律中推导假定的皮层回路，大致遵循演绎 - 律则的解释方式。尽管马尔的理论后来被证明是错误的，但其优点之一是将皮层回路发育问题置于其议程首位。在随后的许多关于典型模型的研究中，这一方面在很大程度上被忽视了。20世纪80年代提出的模型被构想为机械论的。它们确定了少量作为基本回路相互作用的组件，每个组件都被定义为一种功能。由于缺乏可识别的皮层组件，最近的模型被呈现为理想化的典型计算，有别于机械论解释。目前，提出单一典型解释的整个尝试已被批评为误入歧途，皮层统一性的前提也受到了强烈挑战。本文将分析这场辩论。典型回路概念的遗产在近期的大型脑项目（如人类脑计划）中以积极和消极的方式都有所体现。一个积极方面是这些项目可能实现对皮层电活动进行详细模拟的目标，消极方面则是它们是否能够找到模拟回路实际发育方式的方法。
