Endogenous language control in Chinese-English switching: an event-related potentials study.

The neural basis of language switching, especially endogenous language control, remains largely unclear. We used a cue-stimulus paradigm and measured behavioral indices and scalp event-related potentials to investigate the endogenous control of switching between Chinese and English. In the experiment, unbalanced Chinese (L1) - English (L2) speakers named pictures in L1 or L2 according to an auditory cue presented 700 ms (cue-stimulus interval) before the picture onset. The reaction time (RT) was longer in the switch condition and the switch cost (difference of RTs between switch and repeat conditions) of L1 (L2→L1) was greater than L2 (L1→L2). P2 component elicited by the cue onset showed the neural switch cost of L1 at the frontocentral regions, with a leftward distribution, but not the switch cost of L2. The greater switch cost of L1 in behavioral responses and neural activity suggests that the frontocentral areas play an important role in endogenous language control, and switching back to the native language might require more endogenous control.