Simos Panagiotis G, Sarkari Shirin, Castillo Eduardo M, Billingsley-Marshall Rebecca L, Pataraia Ekaterina, Clear Trustin, Papanicolaou Andrew C
Department of Psychology, University of Crete, Rethymno, Crete 74100, Greece.
Clin Neurophysiol. 2005 Oct;116(10):2381-91. doi: 10.1016/j.clinph.2005.06.019.
The purpose of this study was to evaluate the reproducibility of estimates of neurophysiological activity obtained with Magnetic Source Imaging.
Split-half data sets were obtained from 14 healthy volunteers during performance of a continuous recognition task for spoken words. The concurrent validity of spatiotemporal activation maps obtained with this task has been previously verified through comparisons with the Wada test and electrocortical stimulation mapping. Consecutive late activity sources (> 200 ms after stimulus onset) were modeled independently as equivalent current dipoles (ECDs) and used to identify the location of language-specific cortex in the left hemisphere (Wernicke's area).
Linear displacement of the geometric center of the cluster of ECDs in this region ranged between 2 and 8 mm across subjects. Intraparticipant variability (range) in the onset latency of activity was +/-50 ms, while the range of change in global field power for the entire set of ECDs in Wernicke's area was less than 17% in all cases.
The results indicate that despite its many conceptual limitations the ECD model can provide reliable estimates of regional cortical activity associated with the engagement of linguistic processes.
The results highlight the need for reproducibility studies when research questions pose particular requirements for precision of estimates of regional neurophysiological activity.
本研究旨在评估利用磁源成像获得的神经生理活动估计值的可重复性。
从14名健康志愿者在执行连续口语单词识别任务期间获取对分数据集。此前已通过与Wada测试和皮质电刺激图谱比较，验证了用该任务获得的时空激活图谱的同时效度。连续的晚期活动源（刺激开始后>200毫秒）被独立建模为等效电流偶极子（ECDs），并用于确定左半球语言特定皮层（韦尼克区）的位置。
该区域内ECDs簇几何中心的线性位移在不同受试者之间为2至8毫米。活动起始潜伏期的受试者内变异性（范围）为±50毫秒，而韦尼克区内所有ECDs的全局场功率变化范围在所有情况下均小于17%。
结果表明，尽管ECD模型有许多概念上的局限性，但它可以为与语言过程参与相关的区域皮层活动提供可靠的估计。
当研究问题对区域神经生理活动估计的精度有特殊要求时，结果突出了进行可重复性研究的必要性。
