ICA-based spatiotemporal approach for single-trial analysis of postmovement MEG beta synchronization

Po Lei Lee, Yu Te Wu, Li Fen Chen, Yong-Sheng Chen, Chou Ming Cheng, Tzu Chen Yeh, Low Tone Ho, Mau Song Chang, Jen Chuen Hsieh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


The extraction of event-related oscillatory neuromagnetic activities from single-trial measurement is challenging due to the non-phase-locked nature and variability from trial to trial. The present study presents a method based on independent component analysis (ICA) and the use of a template-based correlation approach to extract Rolandic beta rhythm from magnetoencephalographic (MEG) measurements of right finger lifting. A single trial recording was decomposed into a set of coupled temporal independent components and corresponding spatial maps using ICA and the reactive beta frequency band for each trial identified using a two-spectrum comparison between the postmovement interval and a reference period. Task-related components survived dual criteria of high correlation with both the temporal and the spatial templates with an acceptance rate of about 80%. Phase and amplitude information for noise-free MEG beta activities were preserved not only for optimal calculation of beta rebound (event-related synchronization) but also for profound penetration into subtle dynamics across trials. Given the high signal-to-noise ratio (SNR) of this method, various methods of source estimation were used on reconstructed single-trial data and the source loci coherently anchored in the vicinity of the primary motor area. This method promises the possibility of a window into the intricate brain dynamics of motor control mechanisms and the cortical pathophysiology of movement disorder on a trial-by-trial basis.

Original languageEnglish
Pages (from-to)2010-2030
Number of pages21
Issue number4
StatePublished - 1 Jan 2003


  • Event-related synchronization
  • Independent component analysis (ICA)
  • Magnetoencephalography
  • Motor cortex
  • Rolandic rhythm
  • Single-trial


Dive into the research topics of 'ICA-based spatiotemporal approach for single-trial analysis of postmovement MEG beta synchronization'. Together they form a unique fingerprint.

Cite this