The Magnitude of Trial-By-Trial Neural Variability Is Reproducible over Time and across Tasks in Humans.
The Magnitude of Trial-By-Trial Neural Variability Is Reproducible over Time and across Tasks in Humans.
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DOI：
10.1523/eneuro.0292-17.2017
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发表时间：
2017-11
期刊：
影响因子：
3.4
通讯作者：
Dinstein I
中科院分区：
文献类型：
--
作者：
Arazi A;Gonen-Yaacovi G;Dinstein I
大量研究表明，感觉皮层的神经活动随着时间的推移和试验的不同而显著变化，即使受试者被呈现相同的重复刺激或任务。这种逐试验的神经变异性在刺激前阶段相对较大，而在刺激呈现后相对较小（淬灭）。先前的研究表明，神经变异性的大小会影响行为，因此在试验和变异性淬灭较大的个体中，感知表现更好。个体受试者的神经变异性在多大程度上是灵活的还是静态的？在这里，我们使用成年人的脑电图记录来证明视觉皮层的神经变异性大小在不同的任务和记录会话中是非常一致的。虽然个体受试者的神经变异性程度差异很大，但在四个具有不同刺激、时间结构和注意/认知需求的任务以及间隔一年的实验过程中，神经变异性却出奇地稳定。这些实验表明，在成人中，神经变异性的大小大多是固化的个体特征，随着任务或时间的变化很少，并且可能使个体受试者倾向于表现出不同的行为能力。
Numerous studies have shown that neural activity in sensory cortices is remarkably variable over time and across trials even when subjects are presented with an identical repeating stimulus or task. This trial-by-trial neural variability is relatively large in the prestimulus period and considerably smaller (quenched) following stimulus presentation. Previous studies have suggested that the magnitude of neural variability affects behavior such that perceptual performance is better on trials and in individuals where variability quenching is larger. To what degree are neural variability magnitudes of individual subjects flexible or static? Here, we used EEG recordings from adult humans to demonstrate that neural variability magnitudes in visual cortex are remarkably consistent across different tasks and recording sessions. While magnitudes of neural variability differed dramatically across individual subjects, they were surprisingly stable across four tasks with different stimuli, temporal structures, and attentional/cognitive demands as well as across experimental sessions separated by one year. These experiments reveal that, in adults, neural variability magnitudes are mostly solidified individual characteristics that change little with task or time, and are likely to predispose individual subjects to exhibit distinct behavioral capabilities.