Gray Michael J, Frey Hans-Peter, Wilson Tommy J, Foxe John J
The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York 10461, Behavioral and Cognitive Neuroscience Program, The Graduate Center of the City University of New York, New York, New York 10031.
The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center (CERC), Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York 10461, The Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Rose F. Kennedy Center, Bronx, New York 10461, and.
J Neurosci. 2015 Apr 8;35(14):5489-503. doi: 10.1523/JNEUROSCI.2891-14.2015.
Selective attention uses temporal regularity of relevant inputs to bias the phase of ongoing population-level neuronal oscillations. This phase entrainment streamlines processing, allowing attended information to arrive at moments of high neural excitability. How entrainment resolves competition between spatially segregated inputs during visuospatial tasks is not yet established. Using high-density electroencephalography in humans, a bilateral entrainment response to the rhythm (1.3 or 1.5 Hz) of an attended stimulation stream was observed, concurrent with a considerably weaker contralateral entrainment to a competing rhythm. That ipsilateral visual areas strongly entrained to the attended stimulus is notable because competitive inputs to these regions were being driven at an entirely different rhythm. Strong modulations of phase locking and weak modulations of single-trial power suggest that entrainment was primarily driven by phase-alignment of ongoing oscillatory activity. In addition, interhemispheric differences in entrained phase were found to be modulated by attended hemifield, implying that the bilateral nature of the response reflected a functional flow of information between hemispheres. This modulation was strongest at the third of at least four harmonics that were strongly entrained. Ipsilateral increases in alpha-band (8-12 Hz) power were also observed during bilateral entrainment, reflecting suppression of the ignored stimulation stream. Furthermore, both entrainment and alpha lateralization significantly affected task performance. We conclude that oscillatory entrainment is a functionally relevant mechanism that synchronizes endogenous activity across the cortical hierarchy to resolve spatial competition. We further speculate that concurrent suppression of ignored input might facilitate the widespread propagation of attended information during spatial attention.
选择性注意利用相关输入的时间规律性来使正在进行的群体水平神经元振荡的相位产生偏差。这种相位同步简化了处理过程，使被注意的信息能在神经兴奋性较高的时刻到达。在视觉空间任务中，同步是如何解决空间上分离的输入之间的竞争尚未明确。利用高密度脑电图对人类进行研究，观察到对被注意刺激流的节律（1.3或1.5赫兹）存在双侧同步反应，同时对竞争节律的对侧同步则明显较弱。同侧视觉区域强烈同步到被注意的刺激值得注意，因为输入到这些区域的竞争性信息是由完全不同的节律驱动的。锁相的强烈调制和单次试验功率的微弱调制表明，同步主要是由正在进行的振荡活动的相位对齐驱动的。此外，发现同步相位的半球间差异受到被注意半视野的调制，这意味着反应的双侧性质反映了半球之间功能性的信息流。这种调制在至少四个被强烈同步的谐波中的第三个谐波处最强。在双侧同步期间还观察到同侧α波段（8 - 12赫兹）功率增加，这反映了对被忽略刺激流的抑制。此外，同步和α侧化都显著影响任务表现。我们得出结论，振荡同步是一种功能相关的机制，它使整个皮质层级的内源性活动同步，以解决空间竞争。我们进一步推测，同时抑制被忽略的输入可能有助于在空间注意期间被注意信息的广泛传播。
