Brain potential correlates of number errors in the Turkish language

Event-related potentials (ERPs) were recorded from 16 native speakers of Turkish while they watched Turkish sentences flashed upon the screen of a videomonitor. The sentences were three words long and contained a verb at the terminal position that was manipulated (1) to have either the correct or the incorrect number with regard to the subject of the sentence, and (2) to be semantically appropriate, inappropriate or to be a pseudoverb. The ERPs from 19 scalp channels revealed a more positive waveform at the left-fronto-temporal site with an onset latency of about 200 ms for the verbs having the wrong number regardless of the semantic appropriateness of the word, while at right fronto-temporal sites a more negative waveform was observed for plural words only. This number incongruency ERP-effect in Turkish is clearly at odds with findings from other languages.