Influence of Repetitive Light Stimulation on Alpha Dynamics

A relative high power in the alpha band (8 – 13Hz) at a particular EEG position is believed to indicate an active inhibitory state of the corresponding cortical site. According to this hypothesis an active inhibitory state corresponds to a lower engagement of the cortical site and is accompanied by a higher engagement of other sites (possibly neighboring ones). In this project the influence of a repetitive visual stimulation on the alpha band was investigated. A special attention was paid to the difference between the individual alpha frequency and alpha power before and after the stimulation. Data was analyzed by using the matching pursuit time–frequency distribution that provides better resolution in time and frequency than STFT or Wigner–Ville transforms. • The alpha peak frequency changes when a subject is presented with a repetitive visual stimulation • Alpha peak frequency decreases during the repetitive light stimulation in the 5–45Hz frequency band • Alpha peak frequency increases following repetitive light stimulation in the range 0.1 to 0.5Hz and 5 to 45Hz • No significant correlations between alpha power and SSVEP power were found • Slight correlations between stimulation signal at infra–frequencies and alpha peak frequency were found Acknowledgments: Authors would like to acknowledge reviewers Danhua Zhu and Ilija Pjanovic for their useful comments to improve this manuscript.