title: A spatial mixture approach to inferring sub-ROI spatio-temporal patterns from rapid event-related fMRI data.
abstract: Previous works investigated a range of spatio-temporal models for fMRI data analysis to provide robust determination of functional region-of-interest (ROI). We present a novel spatio-temporal fMRI model that is suitable for identifying a number of distinct temporal patterns and their spatial support in the voxel space. Accordingly, fMRI signals on a single voxel are modeled as a probabilistic superposition of those temporal patterns. The spatially varying influence of individual patterns is defined in terms of a parameterised function. The temporal pattern is characterised by both the underlying hemodynamic response function (HRF) and a time series of the individual stimulus-response magnitudes, which makes the proposed model particularly suitable for modeling rapid event-related fMRI data. Moreover, a parametric approach is adopted to represent the HRFs. The resulting methodology is conceptually principled and computationally efficient. We first verify the proposed model in a controlled experimental setting using synthetic data. The model is further applied to analyzing real fMRI data, with focus on functional homogeneity within individual ROIs.
authors.affiliation: School of Computer Science, University of Birmingham, UK.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Shen
authors.affiliation: School of Psychology, University of Birmingham, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Mayhew
authors.affiliation: School of Psychology, University of Birmingham, UK.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Kourtzi
authors.affiliation: School of Computer Science, University of Birmingham, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Tino
mesh_terms: D000465:Algorithms; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D062211:Spatio-Temporal Analysis