Kiebel Stefan, Friston Karl J
The Wellcome Department of Imaging Neuroscience, The Institute of Neurology, 12 Queen Square, WC1N 3BG London, United Kingdom.
Hum Brain Mapp. 2002 May;16(1):36-46. doi: 10.1002/hbm.10021.
We describe the use of anatomically informed basis functions (AIBF) in the analysis of multisubject functional imaging studies. AIBF are used to specify an anatomically informed spatial model that embodies anatomical knowledge for the statistical analysis of neuroimaging data. In a previous communication, we showed how AIBF can be used to incorporate prior anatomical constraints in single subject functional magnetic resonance image (fMRI) analyses to augment their anatomical precision. In this paper, we extend AIBF such that it can be applied to multisubject studies using fMRI or PET. The key concept is that, after spatial normalization, a canonical cortical surface can be used to generate a forward model of signal sources for all subjects. By estimating the hemodynamic signal in this canonical AIBF-space and then projecting it back into the voxel-space, one effectively extracts functional activity that is smooth, within and only within, the cortical sheet while attenuating other components unrelated to the physiological process of interest. The ensuing procedure can be considered as a highly non-stationary, anisotropic anatomically informed [de]convolution or smoothing. It is shown that this procedure offers various advantages compared to existing conventional methods for the analysis of multisubject studies, in particular it is more sensitive to underlying activations.
我们描述了解剖学信息基础函数（AIBF）在多受试者功能成像研究分析中的应用。AIBF用于指定一个体现解剖学知识的空间模型，以对神经影像数据进行统计分析。在之前的一篇通讯中，我们展示了AIBF如何用于在单受试者功能磁共振成像（fMRI）分析中纳入先验解剖学约束，以提高其解剖学精度。在本文中，我们扩展了AIBF，使其能够应用于使用fMRI或PET的多受试者研究。关键概念是，在空间归一化之后，一个标准的皮质表面可用于为所有受试者生成信号源的正向模型。通过在这个标准的AIBF空间中估计血液动力学信号，然后将其投影回体素空间，人们有效地提取了在皮质层内且仅在皮质层内平滑的功能活动，同时衰减了与感兴趣的生理过程无关的其他成分。随后的过程可被视为一种高度非平稳、各向异性的解剖学信息[去]卷积或平滑。结果表明，与现有的用于多受试者研究分析的传统方法相比，该过程具有多种优势，特别是它对潜在激活更敏感。
