SISSA - Cognitive Neuroscience, via Bonomea 265, 34136, Trieste, Italy.
Dip. Psicologia Renzo Canestrari, Univ. Bologna, Viale C. Berti-Pichat 5, 40126, Bologna, Italy.
Exp Brain Res. 2024 May;242(5):1101-1114. doi: 10.1007/s00221-024-06785-z. Epub 2024 Mar 14.
Under what conditions can prefrontal cortex direct the composition of brain states, to generate coherent streams of thoughts? Using a simplified Potts model of cortical dynamics, crudely differentiated into two halves, we show that once activity levels are regulated, so as to disambiguate a single temporal sequence, whether the contents of the sequence are mainly determined by the frontal or by the posterior half, or by neither, depends on statistical parameters that describe its microcircuits. The frontal cortex tends to lead if it has more local attractors, longer lasting and stronger ones, in order of increasing importance. Its guidance is particularly effective to the extent that posterior cortices do not tend to transition from state to state on their own. The result may be related to prefrontal cortex enforcing its temporally-oriented schemata driving coherent sequences of brain states, unlike the atemporal "context" contributed by the hippocampus. Modelling a mild prefrontal (vs. posterior) lesion offers an account of mind-wandering and event construction deficits observed in prefrontal patients.
在什么条件下，前额叶皮层可以指导大脑状态的组成，产生连贯的思维流？我们使用一个简化的皮质动力学 Potts 模型，粗略地分为两半，表明一旦活动水平得到调节，以便消除单个时间序列的歧义，序列的内容主要是由前半部分还是后半部分决定，或者两者都不决定，取决于描述其微电路的统计参数。如果前额叶皮层具有更多的局部吸引子，持续时间更长且更强，则倾向于领先，按重要性递增的顺序排列。它的指导作用特别有效，因为后皮质本身不太倾向于自行从一个状态过渡到另一个状态。其结果可能与前额叶皮层强制其时间导向的图式有关，这些图式驱动着大脑状态的连贯序列，而与海马体提供的无时间的“上下文”不同。模拟轻度前额叶（与后叶相比）损伤可以解释前额叶患者中观察到的思维漫游和事件构建缺陷。
