Is ocular voltage propagation to the electroencephalogram frequency dependent?
Conventional eye correction methods subtract portions (propagation coefficients; Bs) of electrooculogram (EOG) voltages from the electroencephalogram (EEG). The frequency domain approach (FDA) uses different Bs for different frequencies whereas the time domain approach (TDA) uses the same Bs. To determine whether measured Bs are dependent on frequency and whether one should employ frequency-dependent methods, 20 min of EEG from eye movement (EM) and blink data (24 participants) were recorded, and Bs were calculated for eye movement ERPs of differing signal-to-noise ratios for frequency bands ranging from 0 to 40 Hz and compared. At high signal to noise, EM Bs for different frequency bands did not differ, for both vertical and horizontal EOG, at all scalp sites tested. There were small differences in blink Bs for different bands, but smaller than the margin of error of this analysis. This indicates that TDA may be more appropriate than FDA.
Pham
Trieu T H
TT
Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia.
Croft
Rodney J
RJ
Cadusch
Peter J
PJ
D000293:Adolescent; D000328:Adult; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D004585:Electrooculography; D004594:Electrophysiology; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009799:Ocular Physiological Phenomena; D011597:Psychomotor Performance / Q000502:physiology; D012438:Saccades / Q000502:physiology; D055815:Young Adult