Visual symmetry at fixation generates a bilateral Event Related Potential (ERP) called the Sustained Posterior Negativity (SPN). Symmetry presented in the left visual hemifield generates a contralateral SPN over the right hemisphere and vice versa. The current study examined whether the contralateral SPN is modulated by the focus of spatial attention. On each trial there were two dot patterns, one to the left of fixation, and one to the right of fixation. A central arrow cue pointed to one of the patterns and participants discriminated its regularity (symmetry or random). We compared contralateral SPN amplitude generated by symmetry at attended and unattended spatial locations. While the response to attended symmetry was slightly enhanced, the response to unattended symmetry was still substantial. Although visual symmetry detection is a computational challenge, we conclude that the brain processes visual symmetry in unattended parts of the visual field.

中文翻译：

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事件相关电位（ERP）揭示了无人看管视觉区域对视觉对称性的强烈反应

注视时的视觉对称性会产生双边事件相关电位 (ERP)，称为持续后后负性 (SPN)。左视觉半场的对称性会在右半球产生对侧 SPN，反之亦然。目前的研究检查了对侧 SPN 是否受到空间注意力焦点的调节。每次试验都有两种点图案，一种位于注视点左侧，一种位于注视点右侧。中心箭头提示指向其中一种模式，参与者可以辨别其规律性（对称性或随机性）。我们比较了有人值守和无人值守空间位置的对称性产生的对侧 SPN 振幅。虽然对有人参与对称性的反应略有增强，但对无人参与对称性的反应仍然很大。尽管视觉对称检测是一项计算挑战，但我们得出的结论是，大脑在视野中无人参与的部分处理视觉对称。