Research data supporting "Transient Topographical Dynamics of the Electroencephalogram Predict Brain Connectivity and Behavioural Responsiveness During Drowsiness"
This set contains 19 EEG recordings of different participants performing an auditory semantic task as they fell asleep.
The participants were directed to not consume stimulants like coffee and to sleep 1–2 h less than normally before the experiment. All of the subjects were assessed as easy sleepers on the Epworth Sleepiness Scale (scores 7–14).
The stimuli consisted of 96 spoken English words chosen from the CELEX lexical database. Half of the words denoted animals and the other half denoted objects. The subjects were asked to classify each stimulus in its respective category (animal or object) by pressing a button. The stimuli were presented through headphones, with an average distance of 8.4 s (minimum 6.2 s) between consecutive stimuli, as the subjects were lying with their eyes closed in a reclining chair. To facilitate drowsiness, the task was performed in a dark, acoustically and electrically shielded EEG room, and the participants were told that they could fall asleep at any point during the experiment, although they were asked not to stop responding deliberately while still awake.
The electroencephalogram was continuously recorded at 500 samples per second from 64 Ag/AgCl electrodes positioned and labelled according to the extended 10/20 system, with Cz as a reference and including vertical and horizontal electrooculography channels.