Department of Education Sciences for Motor Activity and Sport, University of Rome Foro Italico, Rome, Italy.
Hum Brain Mapp. 2012 Jun;33(6):1334-51. doi: 10.1002/hbm.21285. Epub 2011 Apr 15.
Recordings of event-related potentials (ERPs) were combined with structural and functional magnetic resonance imaging (fMRI) to investigate the timing and localization of stimulus selection processes during visual-spatial attention to pattern-reversing gratings. Pattern reversals were presented in random order to the left and right visual fields at a rapid rate, while subjects attended to the reversals in one field at a time. On separate runs, stimuli were presented in the upper and lower visual quadrants. The earliest ERP component (C1, peaking at around 80 ms), which inverted in polarity for upper versus lower field stimuli and was localized in or near visual area V1, was not modulated by attention. In the latency range 80-250 ms, multiple components were elicited that were increased in amplitude by attention and were colocalized with fMRI activations in specific visual cortical areas. The principal anatomical sources of these attention-sensitive components were localized by fMRI-seeded dipole modeling as follows: P1 (ca. 100 ms-source in motion-sensitive area MT+), C2 (ca. 130 ms-same source as C1), N1a (ca. 145 ms-source in horizontal intraparietal sulcus), N1b (ca. 165 ms-source in fusiform gyrus, area V4/V8), N1c (ca. 180 ms-source in posterior intraparietal sulcus, area V3A), and P2 (ca. 220 ms-multiple sources, including parieto-occipital sulcus, area V6). These results support the hypothesis that spatial attention acts to amplify both feed-forward and feedback signals in multiple visual areas of both the dorsal and ventral streams of processing.
记录事件相关电位 (ERPs) 并结合结构和功能磁共振成像 (fMRI)，以研究在视觉空间注意模式反转光栅时刺激选择过程的时间和定位。模式反转以随机顺序快速呈现到左右视野，而受试者一次只注意一个视野中的反转。在单独的运行中，刺激呈现在上下视觉象限。最早的 ERP 成分 (C1，峰值约 80 ms)，其极性对于上下场刺激反转，定位于或靠近视觉区域 V1，不受注意调制。在 80-250 ms 的潜伏期范围内，诱发出多个成分，这些成分的振幅被注意增强，并且与特定视觉皮质区域的 fMRI 激活重合。通过 fMRI 引导偶极子建模定位这些注意敏感成分的主要解剖学来源如下：P1（约 100 ms-运动敏感区 MT+ 的源）、C2（约 130 ms-C1 的相同源）、N1a（约 145 ms-水平顶内沟的源）、N1b（约 165 ms-梭状回，V4/V8 区的源）、N1c（约 180 ms-后顶内沟，V3A 区的源）和 P2（约 220 ms-多个源，包括顶枕沟，V6 区）。这些结果支持了这样的假设，即空间注意作用于放大背侧和腹侧处理流的多个视觉区域中的前馈和反馈信号。
