Current dipole sources of EEG large particular waves relating to eye movements were estimated around the orbits by the SSB/DT method

2000 ◽  
Vol 38 ◽  
pp. S148
Author(s):  
K Matsunami
Author(s):  
Sergey N. Makarov ◽  
Jyrki Ahveninen ◽  
Matti Hämäläinen ◽  
Yoshio Okada ◽  
Gregory M. Noetscher ◽  
...  

AbstractIn this study, the boundary element fast multipole method or BEM-FMM is applied to model compact clusters of tightly spaced pyramidal neocortical neurons firing simultaneously and coupled with a high-resolution macroscopic head model. The algorithm is capable of processing a very large number of surface-based unknowns along with a virtually unlimited number of elementary microscopic current dipole sources distributed within the neuronal arbor.The realistic cluster size may be as large as 10,000 individual neurons, while the overall computation times do not exceed several minutes on a standard server. Using this approach, we attempt to establish how well the conventional lumped-dipole model used in electroencephalography/magnetoencephalography (EEG/MEG) analysis approximates a compact cluster of realistic neurons situated either in a gyrus (EEG response dominance) or in a sulcus (MEG response dominance).


1989 ◽  
pp. 567-570 ◽  
Author(s):  
N. M. Palfreyman ◽  
K. D. Singh ◽  
S. J. Swithenby

1992 ◽  
Vol 37 (4) ◽  
pp. 845-852 ◽  
Author(s):  
O Oshiro ◽  
M Mukai ◽  
F Takeuchi ◽  
S Kuriki

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Federica Vatta ◽  
Fabio Meneghini ◽  
Fabrizio Esposito ◽  
Stefano Mininel ◽  
Francesco Di Salle

The accuracy of forward models for electroencephalography (EEG) partly depends on head tissues geometry and strongly affects the reliability of the source reconstruction process, but it is not yet clear which brain regions are more sensitive to the choice of different model geometry. In this paper we compare different spherical and realistic head modeling techniques in estimating EEG forward solutions from current dipole sources distributed on a standard cortical space reconstructed from Montreal Neurological Institute (MNI) MRI data. Computer simulations are presented for three different four-shell head models, two with realistic geometry, either surface-based (BEM) or volume-based (FDM), and the corresponding sensor-fitted spherical-shaped model. Point Spread Function (PSF) and Lead Field (LF) cross-correlation analyses were performed for 26 symmetric dipole sources to quantitatively assess models' accuracy in EEG source reconstruction. Realistic geometry turns out to be a relevant factor of improvement, particularly important when considering sources placed in the temporal or in the occipital cortex.


2000 ◽  
Vol 53 (4) ◽  
pp. 1061-1080 ◽  
Author(s):  
Keith Rayner ◽  
Gretchen Kambe ◽  
Susan A. Duffy

2000 ◽  
Vol 59 (2) ◽  
pp. 85-88 ◽  
Author(s):  
Rudolf Groner ◽  
Marina T. Groner ◽  
Kazuo Koga

2007 ◽  
Vol 12 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Géry d'Ydewalle ◽  
Wim De Bruycker

Abstract. Eye movements of children (Grade 5-6) and adults were monitored while they were watching a foreign language movie with either standard (foreign language soundtrack and native language subtitling) or reversed (foreign language subtitles and native language soundtrack) subtitling. With standard subtitling, reading behavior in the subtitle was observed, but there was a difference between one- and two-line subtitles. As two lines of text contain verbal information that cannot easily be inferred from the pictures on the screen, more regular reading occurred; a single text line is often redundant to the information in the picture, and accordingly less reading of one-line text was apparent. Reversed subtitling showed even more irregular reading patterns (e.g., more subtitles skipped, fewer fixations, longer latencies). No substantial age differences emerged, except that children took longer to shift attention to the subtitle at its onset, and showed longer fixations and shorter saccades in the text. On the whole, the results demonstrated the flexibility of the attentional system and its tuning to the several information sources available (image, soundtrack, and subtitles).


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