Spectral analysis of the EEG recorded during stimulation of the human fovea.
Computer spectral analysis was performed on the EEGs of 6 subjects recorded during monocular foveal stimulation. Stimulus wavelength and subjective brightness were varied independently to determine their importance to changes in the ongoing EEG. The contribution of oculomotor control to these effects and the retinal area of their origin were also investigated. The major results were as follows. (1) Stimulation of the fovea reduced the amplitude of the EEG and the coherence between hemispheres at all frequencies, but most dramatically in the alpha band. (2) It increased the variance of EEG amplitudes and widths of spectral peaks in the alpha band and shifted these peaks to lower frequencies. (3) Auto-spectral intensities in the alpha band were enhanced slightly at brightness levels near photopic threshold, but were unaffected by changes in stimulus wavelength. (4) The fovea appeared to be the most effective retinal area in which irradiation attenuated ongoing alpha activity.
D000065:Accommodation, Ocular; D000513:Alpha Rhythm; D003201:Computers; D004569:Electroencephalography; D005260:Female; D005403:Fixation, Ocular; D005584:Fovea Centralis / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D008027:Light; D008266:Macula Lutea / Q000502:physiology*; D008297:Male; D008433:Mathematics; D012160:Retina / Q000502:physiology / Q000528:radiation effects; D013057:Spectrum Analysis