title: Data fusion for paroxysmal events' classification from EEG.
abstract: Spatiotemporal analysis of electroencephalography is commonly used for classification of events since it allows capturing dependencies across channels. The significant increase of feature vector dimensionality however introduce noise and thus it does not allow the classification models to be trained using a limited number of samples usually available in clinical studies.
  
  
  
  Thus, we investigate the classification of epileptic and non-epileptic events based on temporal and spectral analysis through the application of three different fusion schemes for the combination of information across channels. We compare the commonly used early-integration (EI) scheme - in which features are fused from all channels prior to classification - with two late-integration (LI) schemes performing per channel classification when: (i) the temporal context varies significantly across channels, thus local spatial training models are required, and (ii) the spatial variations are negligible in comparison to the inter-subject variation, thus only the temporal variation is modeled using a single global spatial training model. Furthermore, we perform dimensionality reduction either by feature selection or by principal component analysis.
  
  
  
  The framework is applied on events that manifest across most channels, as generalized epileptic seizures, psychogenic non-epileptic seizures and vasovagal syncope. The three classification architectures were evaluated on EEG epochs from 11 subjects.
  
  
  
  Although direct comparison with other studies is difficult due to the different characteristics of each dataset, the achieved recognition accuracy of the LI fusion schemes outperforms the performance reported in the literature.
  
  
  
  The best scheme was the LI with global model which achieved 97% accuracy.
authors.affiliation: Multidimensional Data Analysis and Knowledge Management Laboratory, Dept. of Computer Engineering and Informatics, University of Patras, 26500 Rion-Patras, Greece. Electronic address: pippa@ceid.upatras.gr.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Pippa
authors.affiliation: CVC, Department of Applied Mathematics, Centrale Supélec - Equipe GALEN, INRIA Saclay, France.
authors.forename: Evangelia I
authors.initials: EI
authors.lastname: Zacharaki
authors.affiliation: Dept. of Clinical Neurophysiology and Epilepsies, Guy's &St. Thomas' and Evelina Hospital for Children, NHS Foundation Trust/King's College, London, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Koutroumanidis
authors.affiliation: Multidimensional Data Analysis and Knowledge Management Laboratory, Dept. of Computer Engineering and Informatics, University of Patras, 26500 Rion-Patras, Greece.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Megalooikonomou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods*; D004829:Epilepsy, Generalized / Q000145:classification* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D012640:Seizures / Q000145:classification* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D055815:Young Adult
keywords: Data fusion; EEG classification; Epileptic seizures; PNES; Vasovagal syncope