The Effects Of Transcranial Direct Current Stimulation On Inhibitory Control Training And Its Transfer Effect

Inhibitory control is the basic cognitive ability of human beings to effectively control their own behavior.It is of great significance to find ways to improve the ability of inhibitory control for researching the law of cognitive development and solving some clinical neuropsychiatric problems.With the growing knowledge of cognitive training With the further understanding of cognitive training,it has been found that the performance of cognitive abilities,such as working memory and cognitive flexibility,could be improved instantly through short-term cognitive training,and inhibitory control has also been found to have training effects.On the other side,the maturity of brain stimulation technology has facilitated the study of neural networks for inhibitory control process,and also provided new methods for improving inhibition.These results show that inhibitory control can be improved by different means,but whether the combination of inhibitory control training and brain stimulation technology can make the performance of inhibitory control more improved,and whether this improvement can be transferred to other untrained tasks related to inhibitory control,such as Stroop task and Directed Forgetting task,has not been fully studied.The present study employs two different approach to regulate participants’ inhibitory control performance and to explore whether changes in their inhibitory control performance can have a transfer effect on untrained tasks.There were 117 college students aged 18-26 who participated in two experiments in this study.In the first experiment,the stop signal task were used as the training task for inhibitory control.The participants in the training group need to complete 15 trainings in 17 days,each training was about 20 minutes;the participants in the control group need to complete 15 control tasks in the same time.The control task has the same experimental material as the stop signal task,and the duration is the same.Before and after training,all participants need to complete the stop signal task,Stroop task and directed forgetting task as the measurement of training effect.The results of Experiment1 showed that stop signal task training significantly improved the performance of training group in stop signal task,which indicated that training improves their inhibitory control ability.On the basis of Experiment 1,Experiment 2 divided the participants into four groups and explored the modulation of transcranial direct current stimulation over the pre-SMA on the training effect.Among these groups,the Stimulation-only group received the anodal tDCS over the pre-SMA region and completed the choice reaction time tasks;the Stimulation-training group received the anodal tDCS and completed the stop signal task trainings;the Control group received the sham stimulation of the same region and completed the choice reaction time tasks;the Training-only group received the sham stimulation and completed the stop signal task trainings.The results show that the stop signal task training and the anode tDCS over the pre-SMA can significantly improve the performance of inhibitory control,and the combination of the two methods effectively increase the improvement of performance.In addition,the study also found that the stop signal task training has a positive transfer effect on the Stroop task,but there is no evidence to support the change of inhibition control can regulate the directional forgetting effect.The above results show that both of the anodal tDCS over pre-SMA and the inhibitory control training of stop signal task can effectively improve the inhibitory control performance.And the combination of behavioral training and tDCS further promoted the inhibitory control ability of participants andtransfered to Stroop task which was untrained.However,this improvement had no transfer effect on directed forgetting task.