The Influence Of Rewards On Cognitive Control:the Modulation Of Task Difficulty

The core hypothesis of the DMC(Dual Mechanisms of Cognitive Control Account)is that cognitive control operates through two different modes of operation:‘proactive control' and ‘reactive control'.The proactive control mode can be conceptualized as a form of ‘early selection' in which goal-relevant information is actively maintained in a sustained manner,before a cognitive demand event occurs,to optimally bias attention,perception and action systems in a goal-driven manner.To the contrary,in reactive control,attention is recruited as a ‘late correction' mechanism that is mobilized only when needed,in an instant manner,such as after a high interference event is detected.The AX-continuous performance test(AX-CPT)is a classic paradigm that separates proactive control and reactive control.Previous studies have used rewarded AX-CPT tasks to find that performance contingent rewards enhance proactive control.Although there are many studies on the impact of rewards on cognitive control,most of them are researches on performance contingent reward,and there are few studies on the impact of performance non-contingent reward on cognitive control.The theory of perceptual load theory holds that the difficulty of the task will affect the allocation of resources during the selective attention process,thus affecting cognitive control.It is unclear whether the difficulty of the task will affect the balance of rewards for cognitive control.In order to supplement the blanks of past studies,the following two questions are mainly discussed in this study:(1)How performance contingent rewards and performance non-contingent rewards regulate proactive control and reactive control respectively;(2)Whether the difficulty of the task will modulate the impact of performance contingent rewards and performance non-contingent rewards on cognitive control.The present study uses the rewarded AX-CPT task to investigate these two questions above.Rewarded AX-CPT task presents a reward-related clue before the AX-CPT task and present reward-related feedback after the AX-CPT task.The task difficulty is manipulated by randomly presenting three interfering letters between the cue stimulus and the probe stimulus.The same experimental design and experimental procedures were used for Study 1 and Study 2.The only difference was the awardcriteria.Study 1 explores the impact of performance contingent rewards on cognitive control.Under reward conditions,regardless of whether the participant makes a correct response,he will be rewarded.Study 2 will explore the impact of performance non-contingent rewards on cognitive control.Under reward conditions,only the correct 30 th percentile reaction time for the correct response in the baseline block will be rewarded.The study found that:(1)performance contingent rewards and performance non-contingent rewards both affect the trade-offs of cognitive control,both of which bias individuals toward proactive control;(2)task difficulty adjusts performance contingent rewards on the trade-offs of cognitive control.Compared with difficult tasks,in easy tasks,performance contingent rewards can make the participants enhance proactive control more;task difficulty does not adjust the performance non-contingent rewards on the trade-offs of cognitive control.