Neuroscience Center, University of Helsinki, FIN-00014 Helsinki, Finland.
Proc Natl Acad Sci U S A. 2013 Feb 26;110(9):3585-90. doi: 10.1073/pnas.1216855110. Epub 2013 Feb 11.
Scale-free fluctuations are ubiquitous in behavioral performance and neuronal activity. In time scales from seconds to hundreds of seconds, psychophysical dynamics and the amplitude fluctuations of neuronal oscillations are governed by power-law-form long-range temporal correlations (LRTCs). In millisecond time scales, neuronal activity comprises cascade-like neuronal avalanches that exhibit power-law size and lifetime distributions. However, it remains unknown whether these neuronal scaling laws are correlated with those characterizing behavioral performance or whether neuronal LRTCs and avalanches are related. Here, we show that the neuronal scaling laws are strongly correlated both with each other and with behavioral scaling laws. We used source reconstructed magneto- and electroencephalographic recordings to characterize the dynamics of ongoing cortical activity. We found robust power-law scaling in neuronal LRTCs and avalanches in resting-state data and during the performance of audiovisual threshold stimulus detection tasks. The LRTC scaling exponents of the behavioral performance fluctuations were correlated with those of concurrent neuronal avalanches and LRTCs in anatomically identified brain systems. The behavioral exponents also were correlated with neuronal scaling laws derived from a resting-state condition and with a similar anatomical topography. Finally, despite the difference in time scales, the scaling exponents of neuronal LRTCs and avalanches were strongly correlated during both rest and task performance. Thus, long and short time-scale neuronal dynamics are related and functionally significant at the behavioral level. These data suggest that the temporal structures of human cognitive fluctuations and behavioral variability stem from the scaling laws of individual and intrinsic brain dynamics.
无标度波动在行为表现和神经元活动中普遍存在。在从秒到数百秒的时间尺度内，心理物理动力学和神经元振荡的幅度波动受幂律形式的长程时间相关性 (LRTC) 支配。在毫秒时间尺度上，神经元活动包括级联式神经元爆发，其具有幂律大小和寿命分布。然而，尚不清楚这些神经元标度法则是否与那些描述行为表现的法则相关，或者神经元 LRTC 和爆发是否相关。在这里，我们表明神经元标度法则彼此之间以及与行为标度法则都具有很强的相关性。我们使用源重建的磁和脑电图记录来描述静息状态下皮质活动的动力学。我们在静息状态数据和视听阈刺激检测任务期间发现了神经元 LRTC 和爆发中稳健的幂律标度。行为表现波动的 LRTC 标度指数与解剖学上确定的大脑系统中同时发生的神经元爆发和 LRTC 的标度指数相关。行为指数还与从静息状态条件得出的神经元标度法则以及类似的解剖结构相关。最后，尽管时间尺度不同，但在休息和任务执行期间，神经元 LRTC 和爆发的标度指数都具有很强的相关性。因此，长时和短时神经元动力学在行为水平上是相关的并且具有功能意义。这些数据表明，人类认知波动和行为可变性的时间结构源自个体和内在大脑动力学的标度法则。
