Attention modulates neuronal correlates of interhemispheric integration and global motion perception
Attention modulates neuronal correlates of interhemispheric integration and global motion perception
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DOI：
10.1167/14.12.30
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发表时间：
2014-01-01
影响因子：
1.8
通讯作者：
Boyaci, Huseyin
中科院分区：
文献类型：
--
作者：
Akin, Burak;Ozdem, Ceylan;Boyaci, Huseyin
在人类视觉系统的早期视网膜视区中，来自左右视半野（VHF）的信息在两个半球中对侧处理。尽管有这种分离，我们还是有一个统一的、连贯的、不间断的单一视野的知觉体验。视觉系统如何准确地整合来自两个VHF的信息并实现这种感知体验仍然是未知的。在这项研究中，使用功能磁共振成像，我们探讨了候选地区，参与了大脑半球间的整合和知觉经验的统一，全球运动跨VHF。刺激是二维的，计算机生成的对象，部分在两个VHF。左侧VHF中的视网膜图像始终保持静止，但在实验条件下，由于物体的整体运动，它似乎具有局部运动。这种知觉效应可以通过一个苛刻的固定任务来引导注意力远离全局运动而减弱。结果表明，枕外侧区，包括内侧颞叶复合体，在整个VHF的统一的整体运动的知觉经验的过程中发挥了重要作用。在包括外侧膝状体核和V1在内的早期区域，我们观察到只有当注意力没有被引导离开物体时，这种感知体验才会发生关联。这些研究结果揭示了注意对运动知觉中半球间整合的影响，并暗示高级视觉区域的双侧活动和导致早期区域双侧活动的反馈机制在统一视野的知觉体验中发挥作用。
In early retinotopic areas of the human visual system, information from the left and right visual hemifields (VHFs) is processed contralaterally in two hemispheres. Despite this segregation, we have the perceptual experience of a unified, coherent, and uninterrupted single visual field. How exactly the visual system integrates information from the two VHFs and achieves this perceptual experience still remains largely unknown. In this study using fMRI, we explored candidate areas that are involved in interhemispheric integration and the perceptual experience of a unified, global motion across VHFs. Stimuli were two-dimensional, computer-generated objects with parts in both VHFs. The retinal image in the left VHF always remained stationary, but in the experimental condition, it appeared to have local motion because of the perceived global motion of the object. This perceptual effect could be weakened by directing the attention away from the global motion through a demanding fixation task. Results show that lateral occipital areas, including the medial temporal complex, play an important role in the process of perceptual experience of a unified global motion across VHFs. In early areas, including the lateral geniculate nucleus and V1, we observed correlates of this perceptual experience only when attention is not directed away from the object. These findings reveal effects of attention on interhemispheric integration in motion perception and imply that both the bilateral activity of higher-tier visual areas and feedback mechanisms leading to bilateral activity of early areas play roles in the perceptual experience of a unified visual field.