The influence of the prestimulus EEG-vigilance on the reaction time in an auditory go/no-go task

The individual RT of healthy subjects varies considerably over the course of RT tasks. The altering state of wakefulness during the experiment may induce these RT fluctuations. The Vigilance Algorithm Leipzig (VIGALL) allows the automatic classification of vigilance states on the basis of EEG recordings. We investigated the relationship between the prestimulus EEG-vigilance and the varying individual RT. 119 healthy subjects performed a simple auditory go/no-go task while an EEG was recorded simultaneously. VIGALL was used to classify the prestimulus EEG-vigilance stage. Individual mean RTs were calculated for each EEG-vigilance stage. ANOVAs for repeated measurements were computed to examine the vigilance effect on the RT. Preliminary analyses show significant main effects of the EEG-vigilance concerning the main stage analysis (stages A0, A and B). RTs continuously increased from most alert (EEG-stage A0) to drowsy (EEG-stage B). The substage analysis of the EEG-stages A (A1, A2 and A3) and B (B1, B2/3) did not reveal significant differences. The findings suggest that VIGALL accurately classifies the EEG-main stages. As the algorithm has originally been developed for the classification of resting EEGs, further features might be implemented for ensuring the applicability for different types of EEG recordings, e.g. during RT tasks. The monitoring of vigilance fluctuations by means of VIGALL might help reducing the intraindividual variance during neuro-cognitive measurements.