Source Extraction Representing Thumb and Little Finger Cortical Networks and Intra-Hand-Area Evoked Synchrony

Franca Tecchio, Sara Graziadio, Giulia Barbati, Roberto Sigismondi, Filippo Zappasodi, Camillo Porcaro, Giancarlo Valente, Marco Balsi

Abstract

A novel cerebral source extraction method is proposed (Functional Source Separation, FSS) starting from extra-cephalic magnetoencephalographic (MEG) signals in humans, based on source functional reactivity to the external stimulation. Their activity is obtained all along the rest state and during processing of a simple separate sensory stimuli of thumb or little finger. This method provides cerebral sources describing thumb and little finger primary representations, as demonstrated by their higher responsiveness to the corresponding finger stimuli and their different positions consistent with the homuncular organization. A dynamical index describing intra-regional synchrony was introduced, which showed higher levels when stimulating the thumb with respect to little finger stimulation, selectively in the gamma band ([33, 44]Hz). This indicates that the stimulation of a functionally prevalent finger (thumb) activates a cortical network more synchronized in the gamma band than a non-prevalent one (little finger).

References

  1. Barbati, G., Porcaro, C., Zappasodi, F., Rossini, P.M., Tecchio, F, 2004. Optimization of ICA approach for artifact identification and removal in MEG signals. Clinical Neurophysiology 115:1220-32
  2. Comon, P, 1994. Independent component analysis: a new concept? Signal processing 36:287-314
  3. Crone, N.E., Miglioretti, D.L., Gordon, B., Lesser, R.P., 1998. Functional mapping of human sensorimotor cortex with electrocorticographic spectral analysis: II. Event-related synchronization in the gamma band, Brain 121: 2301- 2315.
  4. Del Gratta, C., Pizzella, V., Tecchio, F., Romani, G.-L, 2001. Magnetoencephalography - a non invasive brain imaging method with 1 ms time resolution Rep Prog Phys 64:1759-1814
  5. Engel, A.K., Fries, P., Singer, W, 2001. Dynamic predictions: oscillations and synchrony in top-down processing. Nat Rev Neurosci 2: 704-716
  6. Engel, A.K., Singer, W., 2001. Temporal binding and the neural correlates of sensory awareness, Trends Cogn. Sci. 5: 16- 25.
  7. Hlustik P, Solodkin A, Gullapalli RP, Noll DC, Small SL, 2001. Somatotopy in human primary motor and somatosensory hand representations revisited. Cereb Cortex. 11: 312- 321.
  8. Meador, K.J., Ray, P.G., Echauz, J.R., Loring, D.W., Vachtsevanos, G.J., 2002 Gamma coherence and conscious perception. Neurology 59: 847-854.
  9. Okada, Y.C., Tanenbaum, R., Williamson, S.J., Kaufman, L., 1984. Somatotopic organization of the human somatosensory cortex revealed by neuromagnetic measurements. Exp Brain Res 56:197-205.
  10. Penfield W, Boldrey E, 1937. Somatic motor and sensory representation in the cerebral cortex of man as studied by electrical stimulation. Brain 60: 389-443.
  11. Pfurtscheller, G., Lopes da Silva, F.H., 1999. Event-related EEG/MEG synchronization and desynchronization: basic principles, Clin. Neurophysiol. 110: 1842- 1857.
  12. Poggio, T., Bizzi, E, 2004. Generalization in vision and motor control. Nature 431:768-74.
  13. Schoffelen, J.M., Oostenveld, R., Fries, P., 2005. Neuronal coherence as a mechanism of effective corticospinal interaction. Science 308:111-113.
  14. Shoham, D., Grinvald, A., 2001. The cortical representation of the hand in macaque and human area S-I: high resolution optical imaging, J. Neurosci. 21: 6820-6835.
  15. Tecchio, F., Padua, L., Aprile, I., Rossini, P.M., 2002. Carpal Tunnel Syndrome modifies sensory hand cortical somatotopy: a MEG study. Hum Brain Mapping 17:28-36
  16. Tecchio, F., Babiloni, C., Zappasodi, F., Vecchio, F., Pizzella, V., Romani, G.-L., Rossini, P.M, 2003. Gamma synchronization in human primary somatosensory cortex as revealed by somatosensory evoked neuromagnetic fields. Brain Res 986: 63-70
  17. Valente, G., Filosa, G., De Martino, F., Formisano, E., Balsi, M.: Optimizing ICA using prior information. In BPC'05 Biosignals Processing and Classification - The International Conference on Informatics in control, Automation and Robotics, Barcelona, Spain.
Download


Paper Citation


in Harvard Style

Tecchio F., Graziadio S., Barbati G., Sigismondi R., Zappasodi F., Porcaro C., Valente G. and Balsi M. (2005). Source Extraction Representing Thumb and Little Finger Cortical Networks and Intra-Hand-Area Evoked Synchrony . In Proceedings of the 1st International Workshop on Biosignal Processing and Classification - Volume 1: BPC, (ICINCO 2005) ISBN 972-8865-35-X, pages 12-18. DOI: 10.5220/0001192400120018


in Bibtex Style

@conference{bpc05,
author={Franca Tecchio and Sara Graziadio and Giulia Barbati and Roberto Sigismondi and Filippo Zappasodi and Camillo Porcaro and Giancarlo Valente and Marco Balsi},
title={Source Extraction Representing Thumb and Little Finger Cortical Networks and Intra-Hand-Area Evoked Synchrony},
booktitle={Proceedings of the 1st International Workshop on Biosignal Processing and Classification - Volume 1: BPC, (ICINCO 2005)},
year={2005},
pages={12-18},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0001192400120018},
isbn={972-8865-35-X},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 1st International Workshop on Biosignal Processing and Classification - Volume 1: BPC, (ICINCO 2005)
TI - Source Extraction Representing Thumb and Little Finger Cortical Networks and Intra-Hand-Area Evoked Synchrony
SN - 972-8865-35-X
AU - Tecchio F.
AU - Graziadio S.
AU - Barbati G.
AU - Sigismondi R.
AU - Zappasodi F.
AU - Porcaro C.
AU - Valente G.
AU - Balsi M.
PY - 2005
SP - 12
EP - 18
DO - 10.5220/0001192400120018