Neurophysiological studies have shown a strong activation in visual areas in response to symmetry. Electrophysiological (EEG) studies, in particular, have confirmed that amplitude at posterior electrodes is more negative for symmetrical compared to asymmetrical patterns. This response is present even when observers perform tasks that do not require processing of symmetry. In this sense the activation is automatic. In this study we test this automaticity more directly by presenting stimuli that contain both symmetry and asymmetry, as overlapping patterns of dots of different colour (black and white). Observers were asked to respond to symmetry in only one of the two colours. If feature-based attention has no role the response should depend on properties of the image. If attention fully filters only the relevant colour the response should depend on properties of the relevant colour only. Neither of these models fully explained the data. We conclude that selective attention does modulate the neural response to symmetry, however we also found a significant contribution from the irrelevant pattern.

神经生理学研究表明，视觉区域对对称性有强烈的反应。尤其是电生理 (EEG) 研究已经证实，与不对称模式相比，对称模式后电极的振幅更负。即使当观察者执行不需要处理对称性的任务时，也会出现这种响应。从这个意义上说，激活是自动的。在这项研究中，我们通过将同时包含对称性和不对称性的刺激呈现为不同颜色（黑色和白色）点的重叠图案来更直接地测试这种自动性。观察者被要求仅对两种颜色中的一种颜色的对称性做出反应。如果基于特征的注意力没有作用，则响应应取决于图像的属性。如果注意力仅完全过滤相关颜色，则响应应仅取决于相关颜色的属性。这些模型都没有完全解释数据。我们得出结论，选择性注意确实会调节对对称性的神经反应，但是我们也发现了无关模式的重要贡献。