Abstract:
:Identification and analysis of directed influences in multivariate systems is an important problem in many scientific areas. Recent studies in neuroscience have provided measures to determine the network structure of the process and to quantify the total effect in terms of energy transfer. These measures are based on joint stationary representations of a multivariate process using vector auto-regressive (VAR) models. A few important issues remain unaddressed though. The primary outcomes of this study are (i) a theoretical proof that the total coupling strength consists of three components, namely, the direct, indirect, and the interference produced by the direct and indirect effects, (ii) expressions to estimate/calculate these effects, and (iii) a result which shows that the well-known directed measure for linear systems, partial directed coherence (PDC) only aids in structure determination but does not provide a normalized measure of the direct energy transfer. Simulation case studies are shown to illustrate the theoretical results.
journal_name
Biol Cybernjournal_title
Biological cyberneticsauthors
Gigi S,Tangirala AKdoi
10.1007/s00422-010-0386-6subject
Has Abstractpub_date
2010-08-01 00:00:00pages
119-33issue
2eissn
0340-1200issn
1432-0770journal_volume
103pub_type
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