Department of Neuroscience and Biomedical Engineering, Aalto University, P.O. Box 12200, FI-00076 Aalto, Finland; Aalto NeuroImaging, Aalto University, FI-00076 Aalto, Finland.
Department of Neuroscience and Biomedical Engineering, Aalto University, P.O. Box 12200, FI-00076 Aalto, Finland; Department of Psychology, University of Jyväskylä, FI-40014, Finland.
Neuroimage. 2021 Feb 15;227:117651. doi: 10.1016/j.neuroimage.2020.117651. Epub 2020 Dec 15.
Reliable paradigms and imaging measures of individual-level brain activity are paramount when reaching from group-level research studies to clinical assessment of individual patients. Magnetoencephalography (MEG) provides a direct, non-invasive measure of cortical processing with high spatiotemporal accuracy, and is thus well suited for assessment of functional brain damage in patients with language difficulties. This MEG study aimed to identify, in a delayed picture naming paradigm, source-localized evoked activity and modulations of cortical oscillations that show high test-retest reliability across measurement days in healthy individuals, demonstrating their applicability in clinical settings. For patients with a language disorder picture naming can be a challenging task. Therefore, we also determined whether a semantic judgment task ('Is this item living?') with a spoken response ("yes"/"no") would suffice to induce comparably consistent activity within brain regions related to language production. The MEG data was collected from 19 healthy participants on two separate days. In picture naming, evoked activity was consistent across measurement days (intraclass correlation coefficient (ICC)>0.4) in the left frontal (400-800 ms after image onset), sensorimotor (200-800 ms), parietal (200-600 ms), temporal (200-800 ms), occipital (400-800 ms) and cingulate (600-800 ms) regions, as well as the right temporal (600-800 ms) region. In the semantic judgment task, consistent evoked activity was spatially more limited, occurring in the left temporal (200-800 ms), sensorimotor (400-800 ms), occipital (400-600 ms) and subparietal (600-800 ms) regions, and the right supramarginal cortex (600-800 ms). The delayed naming task showed typical beta oscillatory suppression in premotor and sensorimotor regions (800-1200 ms) but other consistent modulations of oscillatory activity were mostly observed in posterior cortical regions that have not typically been associated with language processing. The high test-retest consistency of MEG evoked activity in the picture naming task testifies to its applicability in clinical evaluations of language function, as well as in longitudinal MEG studies of language production in clinical and healthy populations.
当从群体研究转向个体患者的临床评估时，可靠的个体脑活动范式和成像测量至关重要。脑磁图（MEG）提供了一种直接的、非侵入性的皮质处理测量方法，具有很高的时空准确性，非常适合评估语言障碍患者的功能性脑损伤。这项 MEG 研究旨在确定延迟图片命名范式中源定位诱发活动和皮质振荡调制，这些活动和调制在健康个体的测量日之间具有高度的测试-重测可靠性，证明了它们在临床环境中的适用性。对于语言障碍患者来说，图片命名可能是一项具有挑战性的任务。因此，我们还确定了一个语义判断任务（“这个项目是活的吗？”）是否足以在与语言产生相关的脑区引起类似的一致活动，该任务要求口语回答“是”/“否”。MEG 数据是在两个不同的日子里从 19 名健康参与者中收集的。在图片命名中，诱发活动在测量日之间是一致的（组内相关系数（ICC）>0.4），在左侧额（图像出现后 400-800 毫秒）、感觉运动（200-800 毫秒）、顶（200-600 毫秒）、颞（200-800 毫秒）、枕（400-800 毫秒）和扣带回（600-800 毫秒）区域，以及右侧颞（600-800 毫秒）区域。在语义判断任务中，一致的诱发活动在空间上更有限，发生在左侧颞（200-800 毫秒）、感觉运动（400-800 毫秒）、枕（400-600 毫秒）和下顶（600-800 毫秒）区域，以及右侧缘上回（600-800 毫秒）。延迟命名任务显示了运动前和感觉运动区域典型的β振荡抑制（800-1200 毫秒），但其他一致的振荡活动调制主要发生在通常与语言处理无关的后皮质区域。图片命名任务中 MEG 诱发活动的高度测试-重测一致性证明了其在语言功能临床评估中的适用性，以及在临床和健康人群中语言产生的纵向 MEG 研究中的适用性。
