Improving proactive control with training on language switching in bilinguals.

The present study examined how a short period of language switching training affects nonverbal cognitive control, as measured by the AX version of the Continuous Performance Test. A group of Chinese-English bilinguals were trained over 10 days on a picture naming task that required switching between languages. We recorded their behavioral performance and event-related potentials before and after the training to examine its effects on cognitive performance. The behavioral measurement of proactive control, that is, goal maintenance before the occurrence of the target, is significantly larger in the post-training phase as compared with the pretraining phase, indicating a proactive control shift. The event-related potential results show that the training led to an increase in the mean amplitude of the N2 component, elicited by both the cue and the probe stimuli. A group of control participants who did not undergo training showed an enlarged N2 only for the probe but not for the cue stimuli in the second as compared with the first phase of testing. No variations in behavioral performance were found in the control group between the two phases of testing. These findings suggest that language switching training enhances proactive control in bilinguals.