Cross-task congruency sequence effect in a predictable task-switching context

국문 초록 (Abstract)

불합치 시행 이후에 합치 시행 이후에 비해 합치 효과가 줄어드는 순차 합치 효과는 인지 통제의 대표적인 지표로, 인지 통제의 범위를 결정하는 요인을 알아내기 위해 많은 연구자들은 서로 다른 과제 사이의 순차 합치 효과를 연구해왔다. 과제 집합 설명은 과제 지시에 따라 형성된 과제 집합이 인지 통제의 범위를 결정한다고 주장하나, 억제 설명은 과제-무관련 자극 차원을 억제하는 방식으로 일어나는 통제 기제를 강조해왔다. 본 연구는 과제 전환이 예측 가능한 상황에서 서로 다른 두 과제 사이의 순차 합치 효과가 과제-관련 자극 차원에 기반한 과제 집합에 의해 결정되는지, 혹은 과제-무관련 차원에 의해 결정되는지 알아보고자 한다. 실험 1부터 3까지는 두 과제 사이에 공유되는 요소를 바꿔가며 두 과제를 두 시행마다 전환해 제시하였다. 실험 4는 두 시행마다 과제를 바꾸면서도 매 시행마다 자극이 제시되는 방향을 바꾸어 시행 간 자극이나 반응 중 어떠한 반복도 없게 하였다. 두 개의 다른 과제 간 순차 합치 효과는 과제-무관련 자극 차원을 공유하는 실험 1, 3, 4에서만 나타났다. 하지만 과제-관련 자극 차원만 공유하는 실험2의 두 과제 사이에서는 순차 합치 효과가 발견되지 않았다. 이러한 결과는 순차 합치 효과가 두 과제가 과제 전환 비용으로 대표되는 과제 간 유사성에 의해 결정되지 않는다는 것을 보여준다. 두 과제가 과제-관련 자극 차원을 공유하는지의 여부보다 과제-무관련 자극 차원이 인지 통제의 범위를 결정한다. 또한 운동 시간에서만 발견되는 순차 합치 효과는 인지 통제가 반응 실행 후 과제-무관련 차원에 의한 반응을 억제하는 방식으로 작동한다는 것을 보여준다.

다국어 초록 (Multilingual Abstract)

The sequential modulation of conflict between two different tasks has been investigated to examine the factor determining the scope of cognitive control involved in the congruency sequence effect (CSE), the phenomenon of the congruency effect being smaller after incongruent trials than after congruent trials. The present study examined whether the CSE being transferred across two tasks in a predictable task-switching context is determined by the task sets established based on the task-relevant stimulus dimension or by the inhibition of the task-irrelevant stimulus dimension. The task set account suggests the task set formed on a basis of task instructions as a factor determining the boundary of control. In contrast, the inhibition account emphasizes that the control mechanism triggered by conflict operates by suppressing the task-irrelevant stimulus dimension, suggesting the task-irrelevant stimulus dimension as a critical factor determining the boundary of control. Two different tasks alternated on every second trials in Experiments 1 to 3, while the shared component of the two tasks changed across the experiments. In Experiment 4, two tasks alternated after two trials, with the orientation of each task alternating on every trial to remove any confounding effect of repetition priming. The sequential modulation of the congruency effect between two tasks was evident in Experiments 1, 3, and 4, all of which shared the task-irrelevant stimulus dimension, regardless of the amount of task-switching cost. However, the congruency effects of the two tasks sharing only the task-relevant stimulus dimension were not sequentially modulated in Experiment 2. These results suggest that whether the CSE occurs between two tasks does not depend on the similarity between the task sets, while the magnitude of similarity is indexed by the task-switching cost. Rather, the task-irrelevant stimulus dimension determines the scope of control, regardless of whether two tasks shared the task-relevant stimulus dimension. Moreover, the congruency sequence effects observed during the response movement times indicates that the control operates in a way to inhibit the task-irrelevant response activation after response initiation.

목차 (Table of Contents)

• Abstract ········································································ⅰ
• List of Figures ································································ ⅲ
• Ⅰ. Introduction ································································ 1
• Ⅱ. Experiment 1 ······························································ 11
• Ⅲ. Experiment 2 ······························································ 23
• Ⅳ. Experiment 3 ······························································ 31
• Ⅴ. Experiment 4 ······························································ 40
• Ⅵ. General Discussion ····················································· 49
• Ⅶ. Conclusion ·································································· 57
• Ⅷ. References ·································································· 58
• 국문초록 ············································································ 63