Research On The Effect Of Top-down Processes On Mixing Cost Of Task Shifting

Everyday life requires frequent shifts between cognitive tasks, referring to the cognitive operation process that conversion from a cognitive task to another task, such as at work, people switch between typing and phone calls and other acts frequently; when preparing dinner, people switch between washing vegetables and cooking; in play, people switch between swing and picking, this human ability to shift fast and smoothly is the basis of executive control and the common research paradigm in executive control of cognitive psychology research. Among them, the researchers believe that switch costs and mixing costs reflect different executive control processes which arising from the task-switching process,now lots of researches on switch cost verify the researchers suspects, but the mixing costs is rarely concerned, so this study concern on whether the mixing costs reflect the process of executive control.This study consists of three behavioral experiments which investigated the effect of top-down processes on mixing cost of task shifting. Experiment 1 is designed to verify whether the mixing costs exist by controlling the response setting. Experiment 2 is to investigated the effect of top-down processes on mixing cost of task shifting by manipulating the presence or absence of cues, Experiment 3 on the basic of the previous study to examine the effect of top-down processes on mixing cost in time pressure. Conclusions as follows:1, Mixing costs both exist in univalent response setting and bivalent response setting.2,When switching tasks, mixing costs in the case of having foreknowledge far smaller than the case of non-existent task cues; and compare to switch costs,3, In time pressure, switch costs decreased, while mixing costs disappear, the subject’s response time faster than without time pressure situation.This study enriched the field of executive control process in task-switching and tried to research the time pressure, which was more closely related to real life and made it more ecological.