Rondina Jane M, Hahn Tim, de Oliveira Leticia, Marquand Andre F, Dresler Thomas, Leitner Thomas, Fallgatter Andreas J, Shawe-Taylor John, Mourao-Miranda Janaina
IEEE Trans Med Imaging. 2014 Jan;33(1):85-98. doi: 10.1109/TMI.2013.2281398. Epub 2013 Sep 11.
Feature selection (FS) methods play two important roles in the context of neuroimaging based classification: potentially increase classification accuracy by eliminating irrelevant features from the model and facilitate interpretation by identifying sets of meaningful features that best discriminate the classes. Although the development of FS techniques specifically tuned for neuroimaging data is an active area of research, up to date most of the studies have focused on finding a subset of features that maximizes accuracy. However, maximizing accuracy does not guarantee reliable interpretation as similar accuracies can be obtained from distinct sets of features. In the current paper we propose a new approach for selecting features: SCoRS (survival count on random subsamples) based on a recently proposed Stability Selection theory. SCoRS relies on the idea of choosing relevant features that are stable under data perturbation. Data are perturbed by iteratively sub-sampling both features (subspaces) and examples. We demonstrate the potential of the proposed method in a clinical application to classify depressed patients versus healthy individuals based on functional magnetic resonance imaging data acquired during visualization of happy faces.
特征选择(FS)方法在基于神经影像学的分类中发挥着两个重要作用:通过从模型中消除无关特征,有可能提高分类准确性,并通过识别最能区分不同类别的有意义特征集来促进解释。尽管专门针对神经影像学数据调整的FS技术的开发是一个活跃的研究领域,但到目前为止,大多数研究都集中在寻找能使准确性最大化的特征子集上。然而,最大化准确性并不能保证可靠的解释,因为从不同的特征集中可以获得相似的准确性。在本文中,我们基于最近提出的稳定性选择理论,提出了一种新的特征选择方法:随机子样本生存计数(SCoRS)。SCoRS依赖于在数据扰动下选择稳定的相关特征的思想。通过对特征(子空间)和示例进行迭代子采样来扰动数据。我们在一个临床应用中展示了所提出方法的潜力,该应用基于在观看快乐面孔时获取的功能磁共振成像数据对抑郁症患者和健康个体进行分类。