Performane of partial directed coherence subject to volume consuction effects.

• Ano de defesa: 2017
• Autor(a) principal: García Rincón, Diana Constanza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: EEG; Eletroencefalografia; Functional connectivity; Partial directed coherence; Processamento de sinais biomédicos; Processamento digital de sinais; Redes complexas; Vector autoregressive model; Volume conduction
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/3/3154/tde-12072017-131157/

The strong relationship between cognitive processing and coherent behaviour and neurocognitive networks justifies the current huge interest in cortical functional connectivity modeling. This has fostered the development of connectivity estimators from the classical bivariate coherence concept to the notion of multivariate partial directed coherence (PDC) which provides information about temporal dependencies exposing cause and effect relationships. This work examines PDC performance for scalp EEG data whose research value has been subject to much debate in the light of the presence of volume conduction (VC) effects that often obscure the actual nature of cortical source dynamics. Through analytical considerations and simulations we show that even though (VC) can hinder accurate connectivity estimation, one can mitigate its effects by a judicious choice of scalp electrode configuration/ground reference. This observation allows settling the connectivity estimation adequacy debate in the presence of PDC.