任务转换是人类认知活动的基本方式,其过程转换加工为中央执行系统的重要功能。转换加工在工作记忆中体现为控制竞争同一认知资源的两项任务之间相互转换的过程。执行转换任务的反应时比执行重复任务的反应时更长,两反应时之差为转换代价。行为实验和神经生理学实验在转换加工的研究范式、转换代价的成分以及执行控制的理论等领域取得一定成果,但也存在诸多争议。事件相关电位和功能磁共振成像技术的联合使用能直观地反映大脑转换加工的时、空动态变化特征,将为转换加工的进一步研究提供证据。
Task switching is a basic manner in human's cognitive activities, and the switching process is an important aspect of executive control, it is considered as controlling switching course between two tasks which compete the same cognitive resources. Switching cost refers to the performance difference in task-switch and task-repeat trials, which is an indicator of executive control. Some critical studies investigating switching process were reviewed in this paper, such as the components and sources of switching cost, behavioral experiments and neuro-physiological studying in this field. In the end, we speculate on the direction of future studies.