WASICA: An effective wavelet-shrinkage based ICA model for brain fMRI data analysis

Nizhuan Wang, Weiming Zeng (Corresponding Author), Yingchao Shi, Tianlong Ren, Yanshan Jing, Jun Yin, Jiajun Yang (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)


Background: Researches declared that the super-Gaussian property contributed to the success of some spatial independent component analysis (ICA) algorithms in brain fMRI source separation (e.g., Infomax and FastICA), which implied that sparse approximation transforming the sources (super-Gaussian or Gaussian-like) with stronger super-Gaussian feature would possibly improve the separation performance of these algorithms. New method: This paper presented a novel wavelet-shrinkage based ICA (WASICA) model, an extension of our previous SACICA, for single-subject analysis. In contrast, two main aspects had been effectively enhanced: (1) sparse approximation coefficients set formation, made up of two sub-procedures: the wavelet-shrinkage of wavelet packet (WP) tree nodes, and the automatic nodes selection and integration based on the relative WP energy; (2) ICA-based decomposition and reconstruction, composed of temporal dynamics extraction using ICA, WP reconstruction based on the sparse approximation coefficients set and least-square-based functional networks reconstruction. Results: The wavelet-shrinkage and the automatic nodes selection and integration simultaneously transformed both the mixtures and underlying sources into effective sparse approximation coefficients sets, exhibiting stronger super-Gaussian distribution; WP projected-back approximation with nuisance-exclusion contributed to networks reconstruction. Comparison with existing methods: Simulation 1 revealed WASICA successfully recovered super-Gaussian and some Gaussian-like sources. Simulation 2 and hybrid data experiments showed that WASICA with good temporal performance had stronger source recovery ability and signal detection sensitivity spatially than FastICA, Infomax and SACICA did; the higher intra-consistency in task-related experiments denoted WASICA occupied stronger spatial robustness against smooth kernels. Conclusions: WASICA was a promising brain signal separation model with charming spatial-temporal performance.

Original languageEnglish
Pages (from-to)75-96
Number of pages22
JournalJournal of Neuroscience Methods
Early online date16 Mar 2015
Publication statusPublished - 15 May 2015
Externally publishedYes


  • FMRI
  • ICA
  • Sparse approximation
  • Wavelet packet decomposition
  • Wavelet shrinkage

ASJC Scopus subject areas

  • General Neuroscience


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