Martin-Loeches M, Barceló F, Rubia F J
Brain Mapping Unit, Complutense University, Madrid, Spain.
Brain Topogr. 1997 Fall;10(1):9-22. doi: 10.1023/a:1022254822290.
This study aimed to finding modality-independent event-related potentials (ERP) modulations related to spatial attention by minimising several possible methodological constrains which may account for the rareness of this finding in past spatial attention ERP research. ERP were recorded while subjects performed a shifting spatial attention task of either auditory, visual or mixed (both auditory and visual) modality. Task requirements and stimulation devices were identical for either modality. Stimuli could appear (80%, valid trials) or not (invalid trials) at predicted locations, and subjects had to perform a speeded response to every stimulus. Reaction time benefits were found for valid trials. Instead of the usually found enhancement of sensory-evoked modality-specific components for valid trials, ERP showed modality-independent modulations as a function of attention. They consisted of a fronto-central activity starting 240 ms after stimulus onset and originated in the anterior cingulate gyrus, followed 40 ms later by a bilateral parietal cortex activation. These processes would be reflecting the activity, respectively, of the anterior and posterior attention systems postulated in Posner's model (Posner and Peterson 1990), which showed a higher degree of participation during invalid trials. P300-like processes were also observed for invalid trials. These results demonstrate that supramodal effects of spatial attention of ERP can be obtained. Furthermore, they extend Posner's model by indicating the timings of implication of the attention subsystems.
本研究旨在通过最小化几种可能的方法学限制来寻找与空间注意相关的模态独立事件相关电位（ERP）调制，这些限制可能是过去空间注意ERP研究中这一发现罕见的原因。在受试者执行听觉、视觉或混合（听觉和视觉）模态的空间注意转移任务时记录ERP。对于任何一种模态，任务要求和刺激设备都是相同的。刺激可能出现在预测位置（80%，有效试验）或不出现在预测位置（无效试验），受试者必须对每个刺激做出快速反应。在有效试验中发现了反应时间优势。与通常在有效试验中发现的感觉诱发模态特异性成分增强不同，ERP显示出与模态无关的注意调制。它们包括刺激开始后240毫秒开始的额中央活动，起源于前扣带回，40毫秒后是双侧顶叶皮层激活。这些过程分别反映了波斯纳模型（波斯纳和彼得森，1990年）中假设的前注意系统和后注意系统的活动，在无效试验中它们的参与程度更高。在无效试验中也观察到了类似P300的过程。这些结果表明，可以获得ERP空间注意的超模态效应。此外，它们通过指出注意子系统的作用时间扩展了波斯纳模型。
