The ERP Study Of Mother Tongue And Second Language Working Memory Stroop Effect

Previous study found that there was Stroop effect in the working memory(WM)(Kiyonaga & Egner,2014).Specifically,a color word(e.g.,the word red printed in black ink)was showed first,then participants were required to respond to the color of the rectangle presented subsequently.Last,a word was presented again and participants were needed to make a judgement about whether the word was same to the first presented word.Results found that compared to the congruent condition(the word meaning first presented was same to the rectangular color),participants showed longer response time(RT)when the color word meaning maintained in the WM was incongruent with the rectangular color.This suggested that the WM content had an impact on the attention performance.And,the magnitude of traditional Stroop effect could be affected by various proficiency materials.However,it's unclear that how was the neural mechanism on the WM Stroop effect.And,whether the materials proficiency could have an impact on the WM Stroop effect.The present study adopted the working memory paradigm and the ERP technique to explore the neural mechanism of the WM Stroop effect.The English color words were adopted in the experiment 1.In the experiment 2,the Chinese characters were adopted and a neutral condition(the neutral words were similar to the color words in structure or number of strokes and had meanings unrelated to color,e.g.,“excellent”,“high”)were added in.The design of the neutral condition was to explore whether there was Stroop interference(RT incongruent > RT neutral)and/or facilitation effect(RT congruent < RT neutral)in the WM.Behavior results found that the incongruent condition had the longer RT than the congruent condition both for the English and Chinese stimuli,indicating the working memory Stroop effect.In addition,the behavior results in the experiment 2 found that the neutral condition showed longer RT than the congruent condition,reflecting the working memory facilitation effect.There was a longer RT for the neutral condition than the incongruent condition,no WM Stroop interference was found.Additionally,the size of WM Stroop effect(RT incongruent – RT congruent)was larger for the Chinese materials than the English materials,reflecting the materials proficiency had an impact on the WM Stroop effect.The ERP results found that during the 250–350 ms time window,compared to the congruent condition,the incongruent condition evoked the larger N2 component,reflecting the process of conflict identification.ERPs results of the experiment 2 also found that the incongruent condition evoked the larger P3(450–700 ms)component relative to the congruent condition,suggesting the conflict resolution process.Moreover,the largest N2 but smallest P3 component was found for the neutral condition,indicating the process of identifying category conflict and less attention resources were needed for resolving the category conflict.In all,these results demonstrated that the congruent content would accelerate the process to the external attention when the information maintained in the working memory was incongruent with the external attention.The increased N2 and P3 component for the incongruent condition reflected the process of identifying and resolving conflict.The proficient materials made the participants produce the large interference.This study also suggested that the working memory and the attention shared the same cognitive resources.