Contributed Talk Sessions | Poster Sessions | All Posters | Search Papers

Poster Session B: Wednesday, August 13, 1:00 – 4:00 pm, de Brug & E‑Hall

Functional Templates in fMRI: Building Accurate and Interpretable Group-Level Decoders

Pierre-Louis Barbarant¹, Florent Meyniel², Bertrand Thirion¹; ¹INRIA, ²CEA

Presenter: Pierre-Louis Barbarant

Anatomical and functional inter-individual variability poses a significant challenge for group analyzes in neuroimaging studies. While anatomical templates help mitigate morphological differences by coregistering subjects in fMRI, they fail to account for functional variability, often leading to blurred activation patterns on the template due to group-level averaging. To address this, hyperalignment identifies fine-grained correspondences between functional brain maps of different subjects, with Procrustes analysis and optimal transport being among the most effective approaches. However many hyperalignment-based imaging studies rely on selecting a single target subject as the reference for aligning all other subjects’ data. We argue that a functional template obviates the need for this arbitrary selection, effectively encapsulating population similarities while preserving anatomical coherence. Using the Individual Brain Charting dataset, we assess the benefit of hyperalignment in template estimation, and the classification accuracy on template aligned-data. Our results show that (a) functional templates produce more localized activation clusters than traditional anatomical averaging, improving the interpretability of population-level studies, and (b) they preserve or enhance the semantic content of brain activations, leading to comparable or higher classification accuracies across most tasks compared to anatomical or pairwise functional alignment.

Topic Area: Methods & Computational Tools

Extended Abstract: Full Text PDF