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脑网络激活中重复模式的识别

Identification of Recurrent Patterns in the Activation of Brain Networks
课程网址: http://videolectures.net/machine_janoos_networks/  
主讲教师: Firdaus Janoos
开课单位: 埃克森美孚公司
开课时间: 信息不详。欢迎您在右侧留言补充。
课程语种: 英语
中文简介:
从大脑活动的神经影像记录中识别与个体不可观察的心理或精神状态相关的模式可以被视为一个无监督的模式识别问题。然而,对fmri数据进行这种分析的主要挑战是:a)定义一个具有生理意义的特征空间,用于表示随时间变化的空间模式;b)处理数据的高维性;以及c)对fmri时间序列中的各种伪影和混淆的鲁棒性。在本文中,我们提出了一个网络感知的特征空间来表示一个普通网络的状态,它能够以一种方式比较和聚类这些状态,即a)对网络连接结构有意义;b)计算效率;c)低维;d)对结构化和随机噪声伪影相对稳健。该特征空间是通过传输距离度量的球面松弛获得的,该度量通过网络传输“质量”以将一个函数转换为另一个函数的成本。通过理论和实证分析,证明了该近似方法的正确性和有效性,特别是对于大问题。虽然这里提出的应用是为了从fmri中识别出不同的大脑活动模式,但是这个特征空间可以应用于在许多不同类型的网络(包括传感器、控制和社交网络)上识别重复出现的模式和检测测量中的异常值的问题。
课程简介: Identifying patterns from the neuroimaging recordings of brain activity related to the unobservable psychological or mental state of an individual can be treated as a unsupervised pattern recognition problem. The main challenges, however, for such an analysis of fMRI data are: a) defining a physiologically meaningful feature-space for representing the spatial patterns across time; b) dealing with the high-dimensionality of the data; and c) robustness to the various artifacts and confounds in the fMRI time-series. In this paper, we present a network-aware feature-space to represent the states of a general network, that enables comparing and clustering such states in a manner that is a) meaningful in terms of the network connectivity structure; b)computationally efficient; c) low-dimensional; and d) relatively robust to structured and random noise artifacts. This feature-space is obtained from a spherical relaxation of the transportation distance metric which measures the cost of transporting ``mass'' over the network to transform one function into another. Through theoretical and empirical assessments, we demonstrate the accuracy and efficiency of the approximation, especially for large problems. While the application presented here is for identifying distinct brain activity patterns from fMRI, this feature-space can be applied to the problem of identifying recurring patterns and detecting outliers in measurements on many different types of networks, including sensor, control and social networks.
关 键 词: 无监督学习; 计算机科学; 机器学习; 半监督学习; 神经生物学
课程来源: 视频讲座网
最后编审: 2019-11-18:cwx
阅读次数: 38