Cognitive Biology, Center for Behavioral Brain Sciences, Otto von Guericke University, 39106 Magdeburg, Germany and Department of Technologies and Health, Istituto Superiore di Sanità, 00161 Roma, Italy.
Cognitive Biology, Center for Behavioral Brain Sciences, Otto von Guericke University, 39106 Magdeburg, Germany.
Phys Rev Lett. 2014 Aug 29;113(9):098103. doi: 10.1103/PhysRevLett.113.098103. Epub 2014 Aug 27.
The timing of certain mental events is thought to reflect random walks performed by underlying neural dynamics. One class of such events--stochastic reversals of multistable perceptions--exhibits a unique scalar property: even though timing densities vary widely, higher moments stay in particular proportions to the mean. We show that stochastic accumulation of activity in a finite number of idealized cortical columns--realizing a generalized Ehrenfest urn model--may explain these observations. Modeling stochastic reversals as the first-passage time of a threshold number of active columns, we obtain higher moments of the first-passage time density. We derive analytical expressions for noninteracting columns and generalize the results to interacting columns in simulations. The scalar property of multistable perception is reproduced by a dynamic regime with a fixed, low threshold, in which the activation of a few additional columns suffices for a reversal.
某些心理事件的时间被认为反映了潜在神经动力学的随机游走。这类事件之一——多稳定感知的随机反转——表现出一个独特的标量性质：尽管时间密度变化很大，但更高阶矩与平均值保持特定的比例。我们表明，在有限数量的理想化皮质柱中的活动的随机积累——实现广义 Ehrenfest urn 模型——可以解释这些观察结果。将随机反转建模为阈值数量的活动柱的首次通过时间，我们得到了首次通过时间密度的更高阶矩。我们为非相互作用的柱导出了解析表达式，并在模拟中将结果推广到相互作用的柱。多稳定感知的标量性质是通过一个具有固定低阈值的动态状态再现的，在这种状态下，几个额外的柱的激活就足以发生反转。
