How Much Seamless Continuity between Prestimulus Alpha Rhythm and Poststimulus Alpha Ringing Has Influence on Visual Evoked Response

Abstract

An influence of the seamless continuity between prestimulus alpha rhythm and poststimulus alpha ringing on visual evoked potential (VEP) has been investigated in nine adult subjects. Alpha ringing is an evoked potential appearing in alpha frequency around the latency of 500ms. The subjects passively viewed a series of 1000 flash stimuli with their eyelids closed throughout the experiment. EEG was simultaneously recorded during the experiment. We classified the epochs into four subsets owing to the seamlessness; how much the phase angle of prestimulus alpha rhythm and the backward-extrapolated phase angle from poststimulus alpha ringing synchronize, and then averaged the epochs within the subsets. Analysis of variance (ANOVA) test indicated that the peak amplitudes of N70 and P100 components were significantly different among subsets. These results imply that the seamless continuity between prestimulus alpha rhythm and poststimulus alpha ringing has influence on VEP.