Title
Sparse representation of working memory processes based on fMRI data
Abstract
Cognitive processes, such as working memory, are widely considered as dynamic, and they are believed to involve complex functional information flows in large-scale brain networks. However, traditional voxel-based fMRI time series analysis methods, which essentially assume that the hemodynamic responses of involved brain regions follow the block or event-related paradigms, are limited in recognizing and modeling this complex process that has been changing in both spatial and temporal spaces. In this paper, we propose a novel computational framework to explore the potential mechanisms underlying the working memory process. Specifically, we adopt the Transfer Entropy (TE) as the measure to model the directional functional interactions based on a series of structurally-consistent cortical landmarks. Then an effective and carefully-designed sparsity learning procedure was applied to derive the most representative interaction patterns for further analysis. Our results show a few cortical landmarks displaying significantly higher interaction strength during the whole fMRI scan and suggest that they might act as hubs in coordinating working memory process. Moreover, four prominent interaction patterns associated with the Default Mode Network (DMN) are found to be attenuated in the task performance period.
Year
DOI
Venue
2014
10.1109/ISBI.2014.6867938
ISBI
Keywords
DocType
ISSN
directional functional interactions,event-related paradigms,cognition,image representation,interaction patterns,default mode network,cortical landmarks,large-scale brain networks,structurally-consistent cortical landmarks,sparse coding,DMN,transfer entropy,working memory processes,functional magnetic resonance imaging,biomedical MRI,voxel-based fMRI time series analysis methods,complex functional information,cognitive processes,brain,task performance,functional interaction,entropy,hemodynamic responses,time series,medical image processing,sparse representation,haemodynamics,sparsity learning procedure
Conference
1945-7928
Citations 
PageRank 
References 
0
0.34
0
Authors
3
Name
Order
Citations
PageRank
Dajiang Zhu132036.72
Xiang Li241.55
Tianming Liu31033112.95