State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China, Department of Psychological Brain Sciences, Dartmouth College, Hanover, New Hampshire 03755, and University of Chinese Academy of Sciences, Beijing, 100049, China.
J Neurosci. 2014 Apr 2;34(14):4837-44. doi: 10.1523/JNEUROSCI.4856-13.2014.
Neuronal oscillations are ubiquitous in the brain and contribute to perception and attention. However, most associated evidence derives from post hoc correlations between brain dynamics and behavior. Although a few recent studies demonstrate rhythms in behavior, it remains largely unknown whether behavioral performances manifest spectrotemporal dynamics in a neurophysiologically relevant manner (e.g., the temporal modulation of ongoing oscillations, the cross-frequency coupling). To investigate the issue, we examined fine spectrotemporal dynamics of behavioral time courses in a large sample of human participants (n = 49), by taking a high time-resolved psychophysical measurement in a precuing attentional task. We observed compelling dynamic oscillatory patterns directly in behavior. First, typical attentional effects are demonstrated in low-pass (0-2 Hz) filtered time courses of behavioral responses. Second, an uninformative peripheral cue elicits recurring α-band (8-20 Hz) pulses in behavioral performances, and the elicited α pulses for cued and uncued conditions are in a temporally alternating relationship. Finally, ongoing α-band power is phase locked to ongoing θ-bands (3-5 Hz) in behavioral time courses. Our findings constitute manifestation of oscillations at physiologically relevant rhythms and power-phase locking, as widely observed in neurophysiological recordings, in behavior. The findings suggest that behavioral performance actually consists of rich dynamic information and may reflect underlying neuronal oscillatory substrates. Our data also speak to a neural mechanism for item attention based on successive cycles (θ) of a sequential attentional sampling (α) process.
神经元振荡在大脑中普遍存在，有助于感知和注意。然而，大多数相关证据来自于大脑动力学和行为之间的事后相关性。尽管最近有几项研究表明行为存在节律，但行为表现是否以神经生理学上相关的方式表现出频谱-时间动力学（例如，正在进行的振荡的时间调制、跨频耦合）仍然很大程度上未知。为了研究这个问题，我们通过在一个预提示注意任务中进行高时间分辨率的心理物理测量，在大量人类参与者（n=49）中检查了行为时间过程的精细频谱-时间动力学。我们在行为中直接观察到了令人信服的动态振荡模式。首先，在行为反应的低通（0-2 Hz）滤波时间过程中显示出典型的注意效应。其次，一个无信息的外围线索在行为表现中引发了重复的α波段（8-20 Hz）脉冲，而提示和未提示条件下引发的α脉冲在时间上呈交替关系。最后，在行为时间过程中，正在进行的α波段功率与正在进行的θ波段（3-5 Hz）相位锁定。我们的发现构成了在生理相关节律和功率-相位锁定中观察到的振荡表现，这在神经生理记录中广泛存在，在行为中也是如此。这些发现表明，行为表现实际上包含了丰富的动态信息，可能反映了潜在的神经元振荡基础。我们的数据也为基于连续注意力采样（α）过程的θ循环的项目注意的神经机制提供了证据。
