Grand average ERPs and polarity maps for rule and phoneme deviants.

<p>ERP graphs reflect the neural responses registered in Fz electrode after standard stimuli (black line), rule deviants (red line) and phoneme deviants (blue line). Polarity maps reflect the activity for all the participants during the P300 time window. The upper panel corresponds to the presentation of deviant stimuli differing in both phonemes and rule from standard stimuli (rule deviants). The lower panel corresponds to the presentation of deviant stimuli differing only in phonemes from standard stimuli (phoneme deviants). A positivity is observed after 300 ms in left frontal region after the presentation of rule deviants.