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High-resolution electro-encephalogram: source estimates of Laplacian-transformed somatosensory-evoked potentials using a realistic subject head model constructed from magnetic resonance images

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Abstract

A novel high-resolution electro-encephalographic (EEG) procedure is proposed, including high spatial sampling (128 channels), a realistic magnetic resonance-constructed subject head model, a multi-dipole cortical source model and regularised weighted minimum-norm linear inverse source estimation (WMN). As an innovation, EEG potentials (two healthy subjects; median-nerve, short-latency somatosensory-evoked potentials (SEPs)) are preliminarily Laplacian-transformed (LT) to remove brain electrical activity generated by subcortical sources (i.e. not represented in the source model). LT-WMN estimates are mathematically evaluated by figures of merit (WMN estimates as a reference). Results show higher dipole identifiability (0.69;0.88), lower dipole localisation error (0.6 mm; 7.8mm) and lower spatial dispersion (8.6 mm; 24mm) in LT-WMN than in WMN estimates (Bonferroni corrected p<0.001). These estimates are presented on the subject modelled cortical surface to highlight the increased spatial information content in LT-WMN compared with WMN estimates. The proposed high-resolution EEG technique is useful for the study of somatosensory functions in basic research and clinical applications.

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Authors and Affiliations

  1. Institute of Human Physiology, University of Rome, Rome, Italy

    F. Babiloni, C. Babiloni & F. Carducci

  2. San Giovanni di Dio, Istituto Sacro Cuore di Gesu, IRCCS, Brescia, Italy

    P. M. Rossini

  3. A. Fa. R. CRCCS, Divisione di Neurologia, Osp. Fatebene Fratelli Isola Tiberina, Rome, Italy

    L. Locche

  4. Laboratory of Computational Engineering, Helsinki University of Technology, Espoo, Finland

    F. Babiloni & C. Babiloni

  5. Fondazione ‘Santa Lucia’, IRCCS, Rome, Italy

    F. Cincotti

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  1. F. Babiloni
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  2. C. Babiloni
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  3. L. Locche
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  4. F. Cincotti
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  5. P. M. Rossini
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  6. F. Carducci
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Babiloni, F., Babiloni, C., Locche, L. et al. High-resolution electro-encephalogram: source estimates of Laplacian-transformed somatosensory-evoked potentials using a realistic subject head model constructed from magnetic resonance images. Med. Biol. Eng. Comput. 38, 512–519 (2000). https://doi.org/10.1007/BF02345746

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  • DOI: https://doi.org/10.1007/BF02345746

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