To Perceive or Not Perceive: The Role of Gamma-band Activity in Signaling Object Percepts
To Perceive or Not Perceive: The Role of Gamma-band Activity in Signaling Object Percepts
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DOI：
10.1371/journal.pone.0066363
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发表时间：
2013-06-13
期刊：
影响因子：
3.7
通讯作者：
Castelo-Branco, Miguel
中科院分区：
文献类型：
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作者：
Castelhano, Joao;Rebola, Jose;Castelo-Branco, Miguel
γ-波段同步性与整体知觉的关系涉及感觉加工、高级知觉完形形成、运动计划和反应的影响，目前仍存在争议。为了提供一个更直接的联系，新兴的知觉状态，我们使用了整体EEG/ERP范式的时刻知觉“发现”的一个全球模式是可变的。使用一个快速的视觉呈现的短命的穆尼对象，我们发现增加的伽马波段活动锁定的感知事件。使用动态穆尼刺激的其他实验表明，伽马活动在紧急整体感知报告之前就增加了。为了以数据驱动的方式确认这些发现，我们进一步使用了支持向量机分类方法，基于时频特征来区分感知状态与非感知状态。敏感性、特异性和准确性均在95%以上。在30-75 Hz范围内的调制对于感知状态更大。有趣的是，相位同步对于高频带的感知状态更大。通过关注全局完形机制而不是局部处理，我们得出结论，γ-波段活动和同步性提供了变量发作的整体感知状态的签名，这是可分离的感觉和运动处理。
The relation of gamma-band synchrony to holistic perception in which concerns the effects of sensory processing, high level perceptual gestalt formation, motor planning and response is still controversial. To provide a more direct link to emergent perceptual states we have used holistic EEG/ERP paradigms where the moment of perceptual "discovery'' of a global pattern was variable. Using a rapid visual presentation of short-lived Mooney objects we found an increase of gamma-band activity locked to perceptual events. Additional experiments using dynamic Mooney stimuli showed that gamma activity increases well before the report of an emergent holistic percept. To confirm these findings in a data driven manner we have further used a support vector machine classification approach to distinguish between perceptual vs. non perceptual states, based on time-frequency features. Sensitivity, specificity and accuracy were all above 95%. Modulations in the 30-75 Hz range were larger for perception states. Interestingly, phase synchrony was larger for perception states for high frequency bands. By focusing on global gestalt mechanisms instead of local processing we conclude that gamma-band activity and synchrony provide a signature of holistic perceptual states of variable onset, which are separable from sensory and motor processing.