کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
945286 | 925775 | 2008 | 14 صفحه PDF | دانلود رایگان |
Global organizational principles are critical for understanding cortical functionality. Recently, we proposed a global sub-division of the posterior cortex into two large-scale systems. One system, labeled extrinsic, comprises the sensory–motor cortex, and is associated with the external environment. The second system, labeled intrinsic, overlaps substantially with the previously described “default-mode” network, and is likely associated with inner-oriented processing. This global partition of the cerebral cortex emerged from hemodynamic imaging data the analysis of which was constrained by pre-determined hypotheses. Here we applied a hypothesis-free, unsupervised two-class clustering algorithm (k-means) to a large set of fMRI data. The two clusters delineated by this unsupervised hypothesis-free procedure showed high anatomical consistency across individuals, and their cortical topography coincided largely with the previously determined extrinsic and intrinsic systems. These new clustering-based results confirm that the intrinsic–extrinsic subdivision constitutes a fundamental cortical divide.
Journal: Neuropsychologia - Volume 46, Issue 2, 2008, Pages 540–553