Clustering fMRI data with a robust unsupervised learning algorithm for neuroscience data mining

• Published in: Journal of neuroscience methods Vol. 299; pp. 45 - 54
• Main Authors: Aljobouri, Hadeel K., Jaber, Hussain A., Koçak, Orhan M., Algin, Oktay, Çankaya, Ilyas
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2018
• Subjects: Algorithms; Brain - physiology; Brain Mapping - methods; Cluster Analysis; Clustering technique; Data mining; Data Mining - methods; Growing neural gas (GNG); Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Neural Networks (Computer); Neurosciences - methods; Robust growing neural gas (RGNG); Signal Processing, Computer-Assisted; Unsupervised Machine Learning; Robust growing neural gas (RGNG); Clustering technique; Data mining; Growing neural gas (GNG)
• ISSN: 0165-0270; 1872-678X
• DOI: 10.1016/j.jneumeth.2018.02.007

•A novel application of the robust unsupervised learning approach is proposed in the current study. Robust growing neural gas (RGNG) algorithm was fed into fMRI data and compared with growing neural gas (GNG) algorithm, which has not been used for this purpose or any other medical application.•Learning algorithms proposed in the current study are fed with real and free auditory fMRI datasets.•Another comparison was conducted with the model-based (hypothesis) data analysis approach using the statistical parametric mapping (SPM) package, which is based on the general linear model.•The fMRI result obtained by running RGNG was within the expected outcome and is similar to those found with the hypothesis method in detecting active areas within the expected auditory cortices.•Results show that the fMRI application of the presented RGNG approach is clearly superior to other approaches in terms of its insensitivity to different initializations and the presence of outliers, as well as its ability to determine the actual number of clusters successfully, as indicated by its performance measured by minimum description length (MDL) and receiver operating characteristic (ROC) analysis. Clustering approaches used in functional magnetic resonance imaging (fMRI) research use brain activity to divide the brain into various parcels with some degree of homogeneous characteristics, but choosing the appropriate clustering algorithms remains a problem. A novel application of the robust unsupervised learning approach is proposed in the current study. Robust growing neural gas (RGNG) algorithm was fed into fMRI data and compared with growing neural gas (GNG) algorithm, which has not been used for this purpose or any other medical application. Learning algorithms proposed in the current study are fed with real and free auditory fMRI datasets. The fMRI result obtained by running RGNG was within the expected outcome and is similar to those found with the hypothesis method in detecting active areas within the expected auditory cortices. The fMRI application of the presented RGNG approach is clearly superior to other approaches in terms of its insensitivity to different initializations and the presence of outliers, as well as its ability to determine the actual number of clusters successfully, as indicated by its performance measured by minimum description length (MDL) and receiver operating characteristic (ROC) analysis. The RGNG can detect the active zones in the brain, analyze brain function, and determine the optimal number of underlying clusters in fMRI datasets. This algorithm can define the positions of the center of an output cluster corresponding to the minimal MDL value.