title: Independent component model for cognitive functions of multiple subjects using [15O]H2O PET images.
abstract: An independent component model of multiple subjects' positron emission tomography (PET) images is proposed to explore the overall functional components involved in a task and to explain subject specific variations of metabolic activities under altered experimental conditions utilizing the Independent component analysis (ICA) concept. As PET images represent time-compressed activities of several cognitive components, we derived a mathematical model to decompose functional components from cross-sectional images based on two fundamental hypotheses: (1) all subjects share basic functional components that are common to subjects and spatially independent of each other in relation to the given experimental task, and (2) all subjects share common functional components throughout tasks which are also spatially independent. The variations of hemodynamic activities according to subjects or tasks can be explained by the variations in the usage weight of the functional components. We investigated the plausibility of the model using serial cognitive experiments of simple object perception, object recognition, two-back working memory, and divided attention of a syntactic process. We found that the independent component model satisfactorily explained the functional components involved in the task and discuss here the application of ICA in multiple subjects' PET images to explore the functional association of brain activations.
authors.affiliation: Brain-Korea21, Human Life Sciences and Clinical Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hae-Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Jae-Jin
authors.initials: JJ
authors.lastname: Kim
authors.forename: Tak
authors.initials: T
authors.lastname: Youn
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D010104:Oxygen Radioisotopes; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D014055:Tomography, Emission-Computed / Q000379:methods*
chemical_list: D010104:Oxygen Radioisotopes