VISUALIZING HIGH DIMENSIONAL FUNCTIONAL DATA SETS FOR TASK fMRI DATA EXPLORATION
Task-based functional magnetic resonance imaging (task fMRI) is a non-invasive technique that allows identifying brain regions whose activity changes when individuals are asked to perform a given task. This contributes to the understanding of how the human brain is organized in functionally distinct subdivisions. Task fMRI experiments from high-resolution scans provide hundred of thousands of longitudinal signals for each individual, corresponding to measurements of brain activity on each voxel of the brain over the duration of the experiment. In collaboration with the Biomedical Imaging and lnstrumentation Group of the Hospital General Universitario Gregorio Marañón (Madrid, Spain) we are working in visualization techniques for this kind of high dimensional data. We rely on robust statistic theory that allows for computationally efficient 2-dim representations of tfMRI data and that shed light on sample composition, outlier presence and individual variability. This exploratory step is crucial previous to any inferential approach willing to identify neuroscientific patterns across individuals, tasks and brain regions.