Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 15, 00135, Rome, Italy.
University Niccolò Cusano, Rome, Italy.
Brain Struct Funct. 2018 Apr;223(3):1343-1355. doi: 10.1007/s00429-017-1560-6. Epub 2017 Nov 9.
Using two independent electrical neuroimaging techniques (BESA and sLORETA), we tested a fMRI-seeded source modeling indicating that in visual discriminative tasks the anterior insula (aIns) participates in the generation of three prefrontal ERP components: the pN1 (at 115 ms), the pP1 (at 170 ms), and the pP2 (at 300 ms). This latter component represented the focus of the present study. Results showed that the pP2 had different activation profiles across hemispheres. The left aIns activity peaked at 420 ms (30 ms before the response) for both Go and No-go trials, that is independently from the ultimate choice (response or inhibition). The right aIns activity started at about 250 ms and progressively increased for a time interval extending after the motor response; its amplitude was larger in case of Go than No-go stimuli. We suggest that the activation of the left aIns reflected the timing of the decision, and the right aIns the categorization and the performance monitoring processes. A control experiment requiring simple (not discriminative) motor response revealed that the pP2 and the aIns activity were nearly absent after the 250 ms; this result confirmed that the aIns activity at this stage is associated with the decisional processes, and not with the motor response per se. The present investigation shed new lights on the insular contribution to perceptual decision-making, and opens to the possibility of assessing the aIns activity via ERP analysis.
使用两种独立的电神经影像学技术（BESA 和 sLORETA），我们测试了 fMRI 种子源建模，表明在前瞻性的 ERP 成分（pN1 在 115ms，pP1 在 170ms，和 pP2 在 300ms）生成过程中，前岛叶（aIns）在前瞻性的 fMRI 种子源建模中参与视觉判别任务。后一个成分是本研究的重点。结果表明，pP2 在半球之间具有不同的激活模式。左前岛叶的活动在 Go 和 No-go 试验中都在 420ms（反应前 30ms）达到峰值，这与最终的选择（反应或抑制）无关。右前岛叶的活动在大约 250ms 开始，并在反应后一段时间内逐渐增加；对于 Go 刺激，其幅度大于 No-go 刺激。我们认为，左前岛叶的激活反映了决策的时间，而右前岛叶的激活反映了分类和绩效监测过程。一个需要简单（非判别）运动反应的控制实验表明，pP2 和 aIns 活动在 250ms 后几乎不存在；这一结果证实，该阶段的 aIns 活动与决策过程有关，而不是与运动反应本身有关。本研究为岛叶对知觉决策的贡献提供了新的见解，并为通过 ERP 分析评估 aIns 活动开辟了可能性。
