2.3.2. EEG recording
Electroencephalographic (EEG) signals were sampled at 1000 Hz
from 64 Ag/AgCl electrodes fitted on a standard electrode layout
elasticized cap using a BrainAmp DC amplifier (Brain Products
GmbH) with a common FCz reference and online low-pass filtered
at 250 Hz. Impedances were below 5kU. Recordings were analyzed
offline using Brain Electrical Source Analysis software v5.3 (BESA
GmbH). Artifacts including blinks and eye movements were corrected
using BESA automatic artifact correction (Berg and Scherg,
1994), and any remaining epochs containing artifacts 100 mV
were rejected. The rejection rate never exceeded 10% of trials for
each participant and stimulus.