Is coding a relevant metaphor for the brain?
Is coding a relevant metaphor for the brain?
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DOI：
10.1017/s0140525x19000049
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发表时间：
2019-01-01
影响因子：
29.3
通讯作者：
Brette, Romain
中科院分区：
文献类型：
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作者：
Brette, Romain
“神经编码”是神经科学中一个流行的比喻，世界的客观属性以尖峰的形式传达给大脑。在这里，我认为这种比喻往往是不恰当的和误导。首先，当神经元被称为编码实验参数时，神经代码取决于编码变量未携带的实验细节（例如，尖峰计数）。因此，神经代码的表征能力比通常所暗示的要有限得多。第二，神经代码只通过引用具有已知意义的事物来传递信息。相比之下，感知系统必须从感觉信号和动作之间的关系中构建信息，形成内部模型。神经代码不足以达到这个目的，因为它们是非结构化的，因此无法表示关系。第三，编码变量是与实验的时间性相关的可观测量，而尖峰是在分布式动力系统中调解耦合的定时动作。编码隐喻试图将大脑的动态、循环和分布式因果结构融入可观察事物之间的线性转换链中，但这两种因果结构是不一致的。我的结论是，神经编码隐喻不能提供一个有效的基础理论的大脑功能，因为它是不相容的因果结构的大脑和认知的表征要求。
"Neural coding" is a popular metaphor in neuroscience, where objective properties of the world are communicated to the brain in the form of spikes. Here I argue that this metaphor is often inappropriate and misleading. First, when neurons are said to encode experimental parameters, the neural code depends on experimental details that are not carried by the coding variable (e.g., the spike count). Thus, the representational power of neural codes is much more limited than generally implied. Second, neural codes carry information only by reference to things with known meaning. In contrast, perceptual systems must build information from relations between sensory signals and actions, forming an internal model. Neural codes are inadequate for this purpose because they are unstructured and therefore unable to represent relations. Third, coding variables are observables tied to the temporality of experiments, whereas spikes are timed actions that mediate coupling in a distributed dynamical system. The coding metaphor tries to fit the dynamic, circular, and distributed causal structure of the brain into a linear chain of transformations between observables, but the two causal structures are incongruent. I conclude that the neural coding metaphor cannot provide a valid basis for theories of brain function, because it is incompatible with both the causal structure of the brain and the representational requirements of cognition.