This article focuses on the problem of predicting a response variable based on a network-valued predictor. Our particular motivation is developing interpretable and accurate predictive models for cognitive traits and neuro-psychiatric disorders based on an individual's brain connection network (connectome). Current methods focus on reducing the complex and high-dimensional brain network into a low-dimensional set of pre-specified features prior to applying standard predictive algorithms. Such methods are sensitive to feature choice and inevitably discard information. We instead propose a nonparametric Bayes class of models that utilize information from the entire adjacency matrix defining connections among brain regions in adaptively defining flexible predictive algorithms, while maintaining interpretability. The proposed Bayesian Connectomics (BaCon) model class utilizes Poisson-Dirichlet processes to detect a lower-dimensional, bidirectional (covariate, subject) pattern in the adjacency matrix. The small n, large p problem is transformed into a "small n, small q" problem, facilitating an effective stochastic search of the predictors. A spike-and-slab prior for the cluster predictors strikes a balance between regression model parsimony and flexibility, resulting in improved inferences and test case predictions. We describe basic properties of the BaCon model class and develop efficient algorithms for posterior computation. The resulting methods are shown to outperform existing approaches in simulations and applied to a creative reasoning data set.
翻译:本文侧重于基于网络价值预测器预测响应变量的预测问题。 我们的特殊动机是在个人大脑连接网络(连接网)的基础上,为认知特征和神经精神紊乱开发可解释和准确预测的模型。 目前的方法重点是在应用标准预测算法之前,将复杂和高维的大脑网络缩小为一套低维的预设特征。 这种方法对选择和不可避免地丢弃信息具有敏感性。 我们建议采用非对称的Bayes类模型,利用来自整个相邻矩阵的信息,确定脑区域在适应性界定灵活预测算法方面的连接,同时保持可解释性。 拟议的Bayesian Connectomic(Bacon)模型(Bacon)类模型利用Poisson-Drichlet进程在应用标准预测算法之前,将复杂和高空的大脑(Cobisson,subilate,subject) 模式模式和逻辑分析模型分析模型分析结果分析模型分析模型分析模型分析结果之间, 分析结果分析模型分析结果分析模型分析模型分析结果, 分析模型分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果分析结果。