Empirical Inference Conference Paper 2010

Source Separation and Higher-Order Causal Analysis of MEG and EEG

PDF Web
Thumb ticker sm thumb kun zhang
Empirical Inference

Separation of the sources and analysis of their connectivity have been an important topic in EEG/MEG analysis. To solve this problem in an automatic manner, we propose a twolayer model, in which the sources are conditionally uncorrelated from each other, but not independent; the dependence is caused by the causality in their time-varying variances (envelopes). The model is identified in two steps. We first propose a new source separation technique which takes into account the autocorrelations (which may be time-varying) and time-varying variances of the sources. The causality in the envelopes is then discovered by exploiting a special kind of multivariate GARCH (generalized autoregressive conditional heteroscedasticity) model. The resulting causal diagram gives the effective connectivity between the separated sources; in our experimental results on MEG data, sources with similar functions are grouped together, with negative influences between groups, and the groups are connected via some interesting sources.

Author(s): Zhang, K. and Hyvärinen, A.
Links:
Journal: Uncertainty in Artificial Intelligence: Proceedings of the Twenty-Sixth Conference (UAI 2010)
Pages: 709-716
Year: 2010
Month: July
Day: 0
Editors: Gr{\"u}nwald, P. , P. Spirtes
Publisher: AUAI Press
Bibtex Type: Conference Paper (inproceedings)
Address: Corvallis, OR, USA
Event Name: 26th Conference on Uncertainty in Artificial Intelligence (UAI 2010)
Event Place: Catalina Island, CA, USA
Digital: 0
Electronic Archiving: grant_archive
ISBN: 978-0-9749039-6-5
Language: en
Organization: Max-Planck-Gesellschaft
School: Biologische Kybernetik

BibTex

@inproceedings{6630,
  title = {Source Separation and Higher-Order Causal Analysis of MEG and EEG},
  journal = {Uncertainty in Artificial Intelligence: Proceedings of the Twenty-Sixth Conference (UAI 2010)},
  abstract = {Separation of the sources and analysis of their connectivity have been an important topic in EEG/MEG analysis. To solve this problem in an automatic manner, we propose a twolayer model, in which the sources are conditionally uncorrelated from each other, but not independent; the dependence is caused by the causality in their time-varying variances (envelopes). The model is identified in two steps. We first propose a new source
  separation technique which takes into account the autocorrelations (which may be time-varying) and time-varying variances of the sources. The causality in the envelopes is then discovered by exploiting a special
  kind of multivariate GARCH (generalized autoregressive
  conditional heteroscedasticity) model. The resulting causal diagram gives the effective connectivity between the separated sources; in our experimental results on MEG data, sources with similar functions are grouped together, with negative influences between groups, and the groups are
  connected via some interesting sources.},
  pages = {709-716},
  editors = {Gr{\"u}nwald, P. , P. Spirtes},
  publisher = {AUAI Press},
  organization = {Max-Planck-Gesellschaft},
  school = {Biologische Kybernetik},
  address = {Corvallis, OR, USA},
  month = jul,
  year = {2010},
  slug = {6630},
  author = {Zhang, K. and Hyv{\"a}rinen, A.},
  month_numeric = {7}
}