Timing Of The Appearance Of Distracter On Congruency Sequence Effect:An Eriksen Flanker Task Study

Cognitive control plays a very important role in human life. In the study of cognitive control, there are some kinds of psychological experimental paradigms, such as Flanker, Stroop and Simon tasks. In distracter interference tasks, participants were asked to exclude distractor interference while respond to target stimuli quickly and accurately. It was found that the mean reaction time is longer in incongruent trials than in congruent trials-Congruency Effect. Later studies suggested that the congruent effect is smaller following an incongruent stimulus than a congruent one-Congruency Sequence Effect (CSE).Over the past two decades, two main accounts of the congruency sequence effect have been proposed. One posits that the congruency sequence effect indexes trial-by-trial adjustments of cognitive control. Conflict adaptation theory is the most influential interpretation. The other holds that the congruency sequence effect indexes learning and memory process. There are two main theories-feature integration and contingency learning. It is argued that both conflict adaptation and feature integration contribute to the congruency sequence effect. In addition, a CSE can be observed independent of the typical learning and memory confounds more easily in the prime-probe task than in the classic Flanker, Stroop, or Simon tasks. According to this phenomenon, there is a question that whether timing of the appearance of distracter affect CSE. Some studies suggest that it is necessary to present the distracter before the target for observing a CSE.Combining these two questions above, we explore that timing of the appearance of distracter on congruency sequence effect:an Eriksen flanker task study. There are two digital Flanker task experiments in this paper, one presenting distracter before target, another presenting distractor and targets simultaneously. There is no difference in two experiences expect the factor that whether presenting distractor before target. Previous studies either did not exclude feature integration and contingency learning, or did not removed confounds after the experiments. These results suffered more or less pollution. Our experiments excluded feature integration by ensuring that the target stimulus and distracter stimulus features completely different between successive stimulus, and contingency learning by equaling the occur probability of each type of trial.A processing platform is built for data processing which is competent of analyzing the behavioral data and imaging data at the first level. The Toolkit improves the efficiency and accuracy of data processing greatly, and provides a guarantee for subsequent data analysis.According to the result of two experiments, we can draw some conclusions. Behavioral data:First, there was a significant three-way interaction between presentation mode, previous congruency, and current congruency. Second, CSE is observed both in presenting distracter before target and presenting simultaneously. Third, CSE is larger in presenting distracter before target than in presenting simultaneously. These findings reveal an important determinant of CSE magnitude when the typical learning and memory confounds are absent. Neuroimaging data:First, there was a significant three-way interaction between presentation mode, previous congruency, and current congruency in the region of right precentral gyrus. Second, a significant CSE was also found in the region of right precentral gyrus when the distracter precedes the target. It is suggested that right precentral gyrus is responsible for response of distracter.