WITHDRAWN Forward-projected cortical eigenmodes for sensor space representation of EEG

Thomas M. Menino Convention & Exhibition Center 

Scalp event-related potentials (ERPs) measured with electroencephalography (EEG) are temporally precise but spatially bandwidth-limited: skull and scalp blur cortical signals, and ERP topographies are typically described in electrode space rather than in coordinates tied to cortical anatomy. We introduce a cortex-anchored sensor-space basis by forward-projecting cortical Laplace-Beltrami (LB) eigenmodes through a realistic head model, yielding a fixed multiscale dictionary whose ordering inherits a cortical spatial-frequency structure. We compute LB eigenmodes on the fsaverage template, map them to sensors via a three-layer boundary-element head model, and define a reusable group-montage dictionary. We compare this forward-projected LB basis to (i) spherical harmonics (SPH) on the same montage and (ii) group PCA/ICA bases trained on trial-averaged time-frequency (TF) maps. The results support forward-mapped LB eigenmodes as a compact, anatomy-anchored coordinate system for resting and evoked EEG that complements spherical and data-adaptive bases and provides a general-purpose feature space for geometry-aligned EEG analyses.

EEG

Sensor space representation