Freunberger Roman, Klimesch Wolfgang, Sauseng Paul, Griesmayr Birgit, Höller Yvonne, Pecherstorfer Thomas, Hanslmayr Simon
Department of Psychology, University of Salzburg, Austria.
Brain Res Bull. 2007 Mar 30;71(6):593-600. doi: 10.1016/j.brainresbull.2006.11.014. Epub 2006 Dec 27.
We tested the hypothesis whether images of real objects elicit stronger gamma (>25 Hz) synchronization, when compared with scrambled objects. The background of this study is a recent debate about the functional meaning of evoked and induced gamma oscillations. Brain electrical source analysis (BESA) and low resolution electromagnetic tomography analysis (LORETA) was performed on the basis of the event-related potential (ERP) data. A component at around 230 ms (termed C230) showed strongest differences between objects and scrambled objects. Time-frequency analyses were run across electrodes and within the dipole sources. We found increased gamma event-related synchronization (ERS) between 200 and 300 ms for real objects. This effect was strongest in a fronto-medial source. Induced gamma, as also shown in previous studies, reflects the more task-relevant mechanism where object representations become activated.
我们检验了一个假设，即与杂乱物体相比，真实物体的图像是否会引发更强的伽马（>25赫兹）同步。本研究的背景是近期关于诱发和诱导伽马振荡功能意义的一场争论。基于事件相关电位（ERP）数据进行了脑电源分析（BESA）和低分辨率电磁断层扫描分析（LORETA）。一个约230毫秒的成分（称为C230）在物体和杂乱物体之间表现出最大差异。在电极之间以及偶极源内部进行了时频分析。我们发现真实物体在200至300毫秒之间伽马事件相关同步（ERS）增加。这种效应在额内侧源中最为强烈。如先前研究中所示，诱导伽马反映了与任务更相关的机制，即物体表征被激活。
