Raw Data

Electroencephalogram (EEG) signals were recorded while participants performed a declarative memory task. The experimental paradigm consisted of encoding and retrieval tasks. The experimental paradigm was implemented using Psychophysics Toolbox. All presented words were chosen randomly from a pool of the 3,000 most commonly used 92 words according to Oxford University. In total, 250 words were shown during the encoding task (50% were concrete and 50% were abstract), divided into five lists of 50 words each. A black screen was presented between lists for 5 sec. A trial consisted  of the presentation of the fixation cross on the monitor for 1 sec followed by a  stimulus (a word, specifically an English noun) for 2 sec. Finally, participants were asked to choose, using the keyboard, if the presented word was abstract (e.g., happiness, anger) or concrete (e.g., paint, house) or NA (subjects can select these options whenever they are not sure if the presented word was abstract or concrete) within 2 sec after which the next trial started. Semantic judgment of words was shown high memorability compared to other judgments or the words presented without any judgment. The total duration of the encoding task was 21 m.