haishan liu 1, gwen frishkoff 2, robert frank 1, dejing dou 1 1 university of oregon 2 georgia state...

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Ontology-Based Mining of Brainwaves: a Sequence Similarity Technique for Mapping Alternative Features in Event-Related Potentials (ERP) Data Haishan Liu 1 , Gwen Frishkoff 2 , Robert Frank 1 , Dejing Dou 1 1 University of Oregon 2 Georgia State University

Post on 19-Dec-2015

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  • Slide 1
  • Slide 2
  • Haishan Liu 1, Gwen Frishkoff 2, Robert Frank 1, Dejing Dou 1 1 University of Oregon 2 Georgia State University
  • Slide 3
  • ERP (Event-Related Potentials): a direct measure of neuronal activity Lack of meta-analysis across experiment NEMO (Neural ElectroMagnetic Ontologies) for data sharing and integration Goal of the presented study Mapping alternative sets of ERP spatial and temporal measures
  • Slide 4
  • Alternative sets of ERP metrics
  • Slide 5
  • Semi-structured data
  • Slide 6
  • Uninformative column headers
  • Slide 7
  • Semi-structured data Uninformative column headers Numerical values
  • Slide 8
  • Cluster labels Meaningful labels Point-sequence curve
  • Slide 9
  • Slide 10
  • Slide 11
  • Slide 12
  • Process all point- sequence curves Calculate Euclidean distance between sequences in the Cartesian product set (Cross-spatial join) Metric Set1 Metric Set2
  • Slide 13
  • Slide 14
  • the two datasets contain the same or similar ERP patterns
  • Slide 15
  • 1-to-1 mapping between metrics
  • Slide 16
  • the two datasets contain the same or similar ERP patterns 1-to-1 mapping between metrics Minimum sum of distances 4.01 + 3.74 > 4.08 + 3.57
  • Slide 17
  • Slide 18
  • Wrong Mappings. Precision = 9/13 Gold standard mapping falls along the diagonal cells
  • Slide 19
  • 3-Factor design of experiment data (Fully factorial: 2 x 2 x 2) 2 simulated subject groups (samples) SG1 = sample 1 SG2 = sample 2 2 data decompositions tPCA = temporal PCA decomposition sICA = spatial ICA decomposition 2 sets of alternative metrics m1 = metric set 1 m2 = metric set 2
  • Slide 20
  • Overall Precision: 84.6%
  • Slide 21
  • Use of an ontology to assign meaningful labels to ERP patterns Application of sequence similarity search in discovering mappings across alternative metrics Extension of the instance-level approach in schema matching Articulation of a global minimum heuristic
  • Slide 22
  • Questions and comments? Please contact Haishan Liu ([email protected])