Offline post-processing occurred in the Netstation v.4.4 software package (EGI, Inc.). The EEG data was first processed through a 0.3 Hz first order high-pass filter and a 30 Hz low-pass filter. Then it was segmented to epochs that contained a 100 msec pre-stimulus baseline and a 900 msec post-stimulus interval. Bad eye channels were manually marked and interpolated by surrounding channels. In the next step, artifact rejection was applied, in which bad segments (threshold 200 µV) were marked. Epochs with any eye blink or eye movement (threshold 150 µV) were rejected. Epochs with more than 10 bad channels (40% or more segments marked bad) were rejected as well. Then the remaining bad segments were replaced by surrounding channels. The single trial data were re-referenced from the vertex (Cz) to an average reference of all electrodes because the latter was thought to be a better representation of a true zero (Junghofer, Elbert, Tucker, & Braun, 1999). The data was baseline corrected to the 100 msec pre-stimulus interval. Finally, single trial data was averaged respectively for each condition (reward and non-reward). Participants
