Tallon-Baudry C, Bertrand O, Delpuech C, Pernier J
Brain Signals and Processing Laboratory, Institut National de la Santé et de la Recherche Médicale, Lyon, France.
J Neurosci. 1996 Jul 1;16(13):4240-9. doi: 10.1523/JNEUROSCI.16-13-04240.1996.
Considerable interest has been raised by non-phase-locked episodes of synchronization in the gamma-band (30-60 Hz). One of their putative roles in the visual modality is feature-binding. We tested the stimulus specificity of high-frequency oscillations in humans using three types of visual stimuli: two coherent stimuli (a Kanizsa and a real triangle) and a noncoherent stimulus ("no-triangle stimulus"). The task of the subject was to count the occurrences of a curved illusory triangle. A time-frequency analysis of single-trial EEG data recorded from eight human subjects was performed to characterize phase-locked as well as non-phase-locked high-frequency activities. We found in early phase-locked 40 Hz component, maximal at electrodes Cz-C4, which does not vary with stimulation type. We describe a second 40 Hz component, appearing around 280 msec, that is not phase-locked to stimulus onset. This component is stronger in response to a coherent triangle, whether real or illusory: it could reflect, therefore, a mechanism of feature binding based on high-frequency synchronization. Because both the illusory and the real triangle are more target-like, it could also correspond to an oscillatory mechanism for testing the match between stimulus and target. At the same latencies, the low-frequency evoked response components phase-locked to stimulus onset behave differently, suggesting that low- and high-frequency activities have different functional roles.
γ波段（30 - 60赫兹）的非锁相同步事件引发了人们相当大的兴趣。它们在视觉模态中的一个假定作用是特征绑定。我们使用三种视觉刺激对人类高频振荡的刺激特异性进行了测试：两种连贯刺激（一个卡尼萨三角和一个真实三角形）以及一种非连贯刺激（“无三角形刺激”）。受试者的任务是数出弯曲的虚幻三角形出现的次数。对八名人类受试者记录的单次试验脑电图数据进行了时频分析，以表征锁相和非锁相的高频活动。我们在早期锁相的40赫兹成分中发现，在电极Cz - C4处达到最大值，且该成分不随刺激类型变化。我们描述了第二个40赫兹成分，出现在大约280毫秒左右，它与刺激开始不同步。该成分对连贯三角形（无论是真实的还是虚幻的）的反应更强：因此，它可能反映了基于高频同步的特征绑定机制。由于虚幻三角形和真实三角形都更像目标，它也可能对应于一种用于测试刺激与目标之间匹配度的振荡机制。在相同的潜伏期，与刺激开始锁相的低频诱发反应成分表现不同，这表明低频和高频活动具有不同的功能作用。
