Moritz C H, Haughton V M, Cordes D, Quigley M, Meyerand M E
Department of Radiology, University of Wisconsin, Madison, USA.
AJNR Am J Neuroradiol. 2000 Oct;21(9):1629-35.
Independent component analysis (ICA), unlike other methods for processing functional MR (fMR) imaging data, requires no a priori assumptions about the hemodynamic response to the task. The purpose of this study was to analyze the temporal characteristics and the spatial mapping of the independent components identified by ICA when the subject performs a finger-tapping task.
Ten healthy subjects performed variations of the finger-tapping task conventionally used to map the sensorimotor cortex. The scan data were processed with ICA, and the temporal configuration of the components and their spatial localizations were studied. The locations with activation were tabulated and compared with locations known to be involved in the organization of motor functions in the brain.
Components were identified that correlated to varying degrees with the conventional boxcar reference function. One or more of these components mapped to the sensorimotor cortex, supplementary motor area (SMA), putamen, and thalamus. By means of ICA components, sensorimotor cortex, supplementary motor area, and superior cerebellar activation were identified bilaterally in 100% of the subjects; thalamus activation was contralateral to the active hand in 80%; and putamen activation was contralateral to the active hand in 60%.
ICA processing of multislice fMR imaging data acquired during finger tapping identifies the sensorimotor cortex, SMA, cerebellar, putamen, and thalamic activation. ICA appears to be a method that provides information on both the temporal and spatial characteristics of activation. Multiple task-related components can be identified by ICA, and specific activation maps can be derived from each separate component.
独立成分分析（ICA）与其他处理功能磁共振（fMR）成像数据的方法不同，它无需对任务的血流动力学反应进行先验假设。本研究的目的是分析当受试者执行手指轻敲任务时，由ICA识别出的独立成分的时间特征和空间映射。
10名健康受试者执行了常用于绘制感觉运动皮层的手指轻敲任务的变体。扫描数据用ICA进行处理，并研究成分的时间配置及其空间定位。将激活的位置制成表格，并与已知参与大脑运动功能组织的位置进行比较。
识别出与传统方波参考函数有不同程度相关性的成分。其中一个或多个成分映射到感觉运动皮层、辅助运动区（SMA）、壳核和丘脑。通过ICA成分，在100%的受试者中双侧识别出感觉运动皮层、辅助运动区和小脑上蚓部激活；80%的受试者丘脑激活与活动手对侧；60%的受试者壳核激活与活动手对侧。
对手指轻敲期间采集的多层fMR成像数据进行ICA处理可识别感觉运动皮层、SMA、小脑、壳核和丘脑激活。ICA似乎是一种能提供激活的时间和空间特征信息的方法。ICA可识别多个与任务相关的成分，并可从每个单独成分得出特定的激活图谱。
