Acticap 64ch standard 2

The overt responses were recorded for offline reaction time measurements with PRAAT [42 ]. Errors in naming were detected during the experiment and the corresponding trials were excluded from the analysis.
The EEG setup consisted of 64 active electrodes embedded in a 10–20 international system electrode cap (ActiCAP 64Ch Standard-2, Brain Products), and the data were online referenced to FCz and re-referenced offline to the average of both mastoids. Additionally, three pairs of passive bipolar electrodes were used in order to register eye and lip movements. The vertical EOG was recorded from the electrodes placed above and below the left eye. Two electrodes were placed on the temples in order to record the horizontal EOG. The lip movements (EMG) were registered with the electrodes placed at the left orbicularis oris superior and the right orbicularis oris inferior. The data were recorded at a sampling rate of 1000 Hz.

The EEG was recorded with 64 active electrodes embedded in a fabric cap (actiCAP 64Ch Standard-2; Brain Products GmbH, Munich, Germany), with the following modifications: the reference was moved from the FCz position to the nose tip, and the electrode occupying the Oz position was replaced in the empty FCz position. The PO9 and PO10 electrodes’ positions were reassigned as EOG channels: these posterior electrodes were chosen because they generally did not show any meaningful responses to auditory stimuli in previous experiments. The EOG was recorded with one electrode placed below the left eye and one placed at the right outer canthus of the right eye. Therefore, during the EEG recording, the EOG channels had the same reference as all the other EEG electrodes. Impedance was kept below 10 kΩ (see Supplementary Information).

We recorded EEG using an elastic cap containing 57 active Ag-AgCl electrodes based on the international 10–20 system (ActiCAP 64Ch Standard-2, Brain Products). Seven additional electrodes were placed on both mastoids (reference), the forehead (ground), next to the eyes (EOG), and next to the upper lip and the throat (EMG). EEG signals were referenced to the left mastoid electrode online and re-referenced to the average of the right and left mastoid electrodes offline. EOG was measured with the electrodes placed above and below the right eye (to monitor for vertical eye movements) and on the left and right temples (to monitor for horizontal eye movements). EEG, EOG and EMG signals were sampled at a frequency of 500 Hz and online-filtered with a low cut-off of 0.016 Hz and a high cut-off of 125 Hz. Impedances for EEG electrodes were kept below 20 kΩ.