Martinovic Jasna, Gruber Thomas, Müller Matthias M
Institut für Psychologie I, Universität Leipzig, Leipzig, Germany.
J Cogn Neurosci. 2007 Jun;19(6):921-34. doi: 10.1162/jocn.2007.19.6.921.
Neural mechanisms of object recognition seem to rely on activity of distributed neural assemblies coordinated by synchronous firing in the gamma-band range (>20 Hz). In the present electroencephalogram (EEG) study, we investigated induced gamma band activity during the naming of line drawings of upright objects and objects rotated in the image plane. Such plane-rotation paradigms elicit view-dependent processing, leading to delays in recognition of disoriented objects. Our behavioral results showed reaction time delays for rotated, as opposed to upright, images. These delays were accompanied by delays in the peak latency of induced gamma band responses (GBRs), in the absence of any effects on other measures of EEG activity. The latency of the induced GBRs has thus, for the first time, been selectively modulated by an experimental manipulation that delayed recognition. This finding indicates that induced GBRs have a genuine role as neural markers of late representational processes during object recognition. In concordance with the view that object recognition is achieved through dynamic learning processes, we propose that induced gamma band activity could be one of the possible cortical markers of such dynamic object coding.
物体识别的神经机制似乎依赖于由伽马波段范围（>20赫兹）的同步放电所协调的分布式神经集合的活动。在当前的脑电图（EEG）研究中，我们调查了在直立物体和在图像平面中旋转的物体的线条图命名过程中诱发的伽马波段活动。这种平面旋转范式引发了依赖于视角的处理，导致对方向错乱物体的识别延迟。我们的行为结果显示，与直立图像相比，旋转图像的反应时间延迟。这些延迟伴随着诱发伽马波段反应（GBR）峰值潜伏期的延迟，而对EEG活动的其他指标没有任何影响。因此，诱发GBR的潜伏期首次通过延迟识别的实验操作被选择性地调节。这一发现表明，诱发GBR作为物体识别过程中晚期表征过程的神经标记具有真正的作用。与物体识别是通过动态学习过程实现的观点一致，我们提出诱发伽马波段活动可能是这种动态物体编码的可能的皮层标记之一。
