Event-related potentials reveal an early advantage for luminance contours in the processing of objects
Event-related potentials reveal an early advantage for luminance contours in the processing of objects
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DOI：
10.1167/11.7.1
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发表时间：
2011-01-01
影响因子：
1.8
通讯作者：
Wuerger, Sophie M.
中科院分区：
文献类型：
--
作者：
Martinovic, Jasna;Mordal, Justyna;Wuerger, Sophie M.
物体的检测和识别是视觉感知最重要的目标。我们研究了对象处理的亮度和色度信息的作用，通过比较熟悉的，有意义的对象轮廓与那些新的，非对象轮廓的性能。比较了全色和减色对象（或非对象）轮廓。全彩色刺激同时包含色度和亮度信息，而亮度信息是在减少颜色刺激缺席。所有的刺激都是同样突出的，通过将它们固定在辨别阈值对比度的倍数上。在随后的脑电图实验中，观察者被要求将轮廓分类为物体或非物体。一个优势，在准确性被发现为全彩色刺激减少的颜色刺激，但只有当轮廓描绘的对象，而不是非对象。事件相关电位揭示了这种物体特异性亮度优势的神经相关性。中央-枕叶N1成分的幅度被调制的刺激类的影响被驱动的亮度信息的存在。我们的结论是，高层次的歧视过程中的皮层开始相对较早，只有在亮度信息的存在下表现出对象选择性的影响。这与亮度在辅助对象识别过程中的优越性是一致的。
Detection and identification of objects are the most crucial goals of visual perception. We studied the role of luminance and chromatic information for object processing by comparing performance of familiar, meaningful object contours with those of novel, non-object contours. Comparisons were made between full-color and reduced-color object (or non-object) contours. Full-color stimuli contained both chromatic and luminance information, whereas luminance information was absent in the reduced-color stimuli. All stimuli were made equally salient by fixing them at multiples of discrimination threshold contrast. In a subsequent electroencephalographic experiment observers were asked to classify contours as objects or non-objects. An advantage in accuracy was found for full-color stimuli over the reduced-color stimuli but only if the contours depicted objects as opposed to non-objects. Event-related potentials revealed the neural correlate of this object-specific luminance advantage. The amplitude of the centro-occipital N1 component was modulated by stimulus class with the effect being driven by the presence of luminance information. We conclude that high-level discrimination processes in the cortex start relatively early and exhibit object-selective effects only in the presence of luminance information. This is consistent with the superiority of luminance in subserving object identification processes.