Wright James J, Bourke Paul D
Department of Psychological Medicine, School of Medicine, The University of Auckland Auckland, New Zealand.
EPICentre, The University of New South Wales Sydney, Australia.
Front Comput Neurosci. 2016 Dec 9;10:127. doi: 10.3389/fncom.2016.00127. eCollection 2016.
This paper furthers our attempts to resolve two major controversies-whether gamma synchrony plays a role in cognition, and whether cortical columns are functionally important. We have previously argued that the configuration of cortical cells that emerges in development is that which maximizes the magnitude of synchronous oscillation and minimizes metabolic cost. Here we analyze the separate effects in development of minimization of axonal lengths, and of early Hebbian learning and selective distribution of resources to growing synapses, by showing in simulations that these effects are partially antagonistic, but their interaction during development produces accurate anatomical and functional properties for both columnar and non-columnar cortex. The resulting embryonic anatomical order can provide a cortex-wide scaffold for postnatal learning that is dimensionally consistent with the representation of moving sensory objects, and, as learning progressively overwrites the embryonic order, further associations also occur in a dimensionally consistent framework. The role ascribed to cortical synchrony does not demand specific frequency, amplitude or phase variation of pulses to mediate "feature linking." Instead, the concerted interactions of pulse synchrony with short-term synaptic dynamics, and synaptic resource competition can further explain cortical information processing in analogy to Hopfield networks and quantum computation.
本文进一步推进了我们解决两个主要争议的尝试——γ同步是否在认知中发挥作用,以及皮质柱在功能上是否重要。我们之前曾提出,发育过程中出现的皮质细胞配置是使同步振荡幅度最大化并使代谢成本最小化的配置。在这里,我们通过模拟表明,轴突长度最小化、早期赫布学习以及向生长中的突触选择性分配资源在发育过程中的单独作用是部分拮抗的,但它们在发育过程中的相互作用为柱状和非柱状皮质产生了精确的解剖和功能特性。由此产生的胚胎解剖顺序可以为出生后的学习提供一个全皮质范围的支架,该支架在维度上与移动的感觉对象的表征一致,并且随着学习逐渐覆盖胚胎顺序,进一步的关联也会在维度一致的框架中发生。赋予皮质同步的作用并不要求脉冲有特定的频率、幅度或相位变化来介导“特征链接”。相反,脉冲同步与短期突触动力学的协同相互作用以及突触资源竞争可以类比霍普菲尔德网络和量子计算,进一步解释皮质信息处理。