ausblenden:
Schlagwörter:
-
Zusammenfassung:
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.