Neuroscience Center, University of Helsinki, 00014 Helsinki, Finland, and BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Central Hospital, 00029 Helsinki, Finland.
J Neurosci. 2013 Nov 27;33(48):19023-33. doi: 10.1523/JNEUROSCI.1666-13.2013.
Human capability to concurrently attend and perceive multiple visual objects has a limited and individual capacity of 2-4 objects. Neuronal mechanisms that support the perception of multiple objects and underlie these attentional capacity limits have remained unclear. We investigated the role of neuronal oscillations in multiobject visual perception and in limiting the attentional capacity. To this end, we used parametric multiobject tracking tasks, MEG and EEG recordings, and data-driven source-space analyses to localize the neuronal substrates of task performance. Three lines of evidence suggested a mechanistic role for neuronal oscillations in multiobject attention. First, oscillation amplitudes preceding target events were distinct for subsequently detected and undetected targets and also predicted reaction times to the target events. Second, suppression of θ to low-β (<20 Hz) and strengthening of high-β to γ (20-90 Hz) oscillations in frontoparietal and visual regions were correlated with attentional load. Third, the load-dependent strengthening of γ (30-90 Hz) band oscillations in lateral prefrontal, posterior parietal, and visual cortices predicted interindividual variability in attentional capacity. A progressive recruitment of γ oscillations in sensory, attentional, and executive networks is thus directly correlated with multiobject attentional demands and, in particular, with the individual capability to consciously attend and perceive multiple visual objects concurrently. These data support the hypothesis that γ oscillations contribute both to neuronal object representations and to attentional and executive processing.
人类同时注意和感知多个视觉对象的能力具有有限的个体容量，为 2-4 个对象。支持感知多个对象的神经机制以及这些注意力容量限制的基础仍然不清楚。我们研究了神经元振荡在多目标视觉感知和限制注意力容量中的作用。为此，我们使用参数化多目标跟踪任务、MEG 和 EEG 记录以及数据驱动的源空间分析来定位任务表现的神经元基质。有三条证据表明神经元振荡在多目标注意力中具有机械作用。首先，目标事件之前的振荡幅度对于随后检测到和未检测到的目标是不同的，并且也预测了对目标事件的反应时间。其次，额顶叶和视觉区域中的θ到低-β（<20 Hz）和β到高-β（20-90 Hz）振荡的抑制与注意力负荷相关。第三，外侧前额叶、后顶叶和视觉皮层中γ（30-90 Hz）波段振荡与注意力负荷相关的增强与注意力容量的个体差异相关。因此，γ 振荡在感觉、注意和执行网络中的逐渐招募与多目标注意力需求直接相关，特别是与同时有意识地注意和感知多个视觉对象的个体能力相关。这些数据支持了γ 振荡既有助于神经元对象表示，也有助于注意和执行处理的假设。
