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Abstract

Sustained visual attention in connection with EEG‐vigilance states have not yet been explicitly investigated. In the present study we examined the effect of vigilance on sustained attention in a rapid serial visual presentation (RSVP) task in 2 subject groups with labile and stable EEG‐vigilance regulation patterns. Coloured letter streams flickered at 7.5 Hz and elicited steady‐state visual evoked potential (SSVEP) as an electrophysiological measure of sustained attention in early visual areas. We found that subjects with labile vigilance regulation show 230 Postersitzung 4 significant amplitude increases of SSVEP in the second half of the experiment. According to the vigilance stage classification, a labile pattern demonstrates a rapid decline to lower vigilance stages (e.g. dominant theta and delta activity in EEG), whereas stable vigilance pattern can be characterized by dominant alpha activity during resting‐EEG. Taking that into account, we further investigated cortical sources of alpha and the externally driven 7.5 Hz steady‐state signal. We found practically identical cortical sources for alpha and the SSVEP in early visual areas in both groups. These results suggest that the increase in the steady‐state response in the labile subjects is likely to occur due to weaker competition between alpha (10 Hz) with the 7.5 Hz externally driven network.