Interaction between the flash evoked SSVEPs and the spontaneous EEG activity in children and adults

Objective: To evaluate the interaction between the steady-state visual evoked potentials (SSVEPs) recorded during the intermittent photic stimulation (IPS) and the spontaneous EEG activities both in children and adults. Methods: EEG was recorded during the rest and under 5, 7.5, 10 and 12.5 Hz IPS in 41 children between 3 and 16 years and 10 adults. We distinguished between the spontaneous resting EEG spectra, SSVEPs (1 st harmonic) and undriven (ongoing) EEG spectra recorded during the IPS. Results: We show that IPS influences spontaneous EEG activity by specifically suppressing or desynchronizing individual posterior dominant resting EEG frequencies (DF) in both children and adults. Further, this highly significant and consistent suppressing effect positively correlates with the SSVEPs amplitude. Conclusions: Our data suggest that the desynchronization of the spontaneous EEG activity under IPS and the SSVEPs are related to each other. Significance: These relationships could be interesting to study in pathological conditions where the neural synchronization and the responses to IPS have been shown to be affected, such as epilepsy and schizophrenia. (c) 2006 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.