The Role And Developmental Characteristics Of Inhibition And Retrieval In Task Switching

People must be highly adaptable and flexible when faced with complex environmental changes.This often involves engaging in complex cognitive control processes in order to more actively perform tasks and achieve goals.Task switching is a concept that has been well-established in prior studies on cognitive control.Classic task-switching studies usually involve at least two tasks with specific explanations regarding what task to do at what time and which procedures or rules apply to the stimulus.A switch sequence is defined as two consecutive trials for different tasks,and a repeat sequence is defined as two consecutive trials for the same task.Previous studies have found that people respond more slowly and less accurately to switch sequences than repeat sequences,reflecting the switch cost.The typical explanations of switch cost are Task-Set Reconfiguration theory and Task-Set Inertia theory.Both theories emphasize that the generation of switch cost will be affected by the previous task setting and the current task setting.Task-Set Reconfiguration theory has been proposed to explain switch cost,positing that,in the repeat sequence,participants only need to maintain the preceding task set,whereas,in the switch sequence,they need to inhibite the preceding task set and shift their attention to activate the current task set in order to retrieve the current task response rules,incorporate them into their working memory,and change the preceding response rules.Task-Set Inertia theory advocates that the switch cost is caused by the interference caused by the continuation of the previous task set,and the Asymmetric Switch Cost is a typical finding of the Task-Set inertia theory.Based on the two theories,the inhibition of the previous task set and the retrieval of the current task set are the important factors affecting the task switching process.Although there have been a lot of researches on task switch and some theories have been formed,there are still some problems that need to be further explained.First of all,some researchers have proposed that neither Task-Set Reconfiguration theory nor Task-Set Inertia theory can explain switch cost alone,and an integrated theory should be used to explain the switching mechanism.How the integrable theory explains the switching mechanism has yet to be fully confirmed by research.Second,previous studies have found that inhibition plays a role in task switch,and proposed that appropriate task rules should be retrieved from long-term memory during task switch,but they did not specify the mode of inhibition and retrieval.Several previous studies considered the effect of inhibiting the task set during task switching by applying the backward inhibition paradigm,Within this model,participants are required to switch between three tasks,with the currently relevant task being signaled by a task cue.When switching among three tasks A,B,and C,an "ABA" sequence means switching back to a task that was recently performed,and a "CBA" sequence means switching back to a task that was not recently performed.Researchers have found that RTs are slower for the ABA sequence than for the CBA sequence,yielding what is referred to as an "n-2 repetition cost." However,there is no simultaneous manipulation of inhibition and retrieval in the research,and there is no systematic explanation of the modes of backward inhibition under different retrieval difficulties.Previous studies have found that cues,task types,and response methods can all affect backward inhibition,but few studies have explored the effects of task types that include response key prompts,response difficulty,perception and semantic judgments on inhibition and retrieval modes in task switching.Third,previous studies have found that task switching,as a manifestation of cognitive control,has obvious development characteristics,and inhibition and retrieval involve the function of the prefrontal cortex,its development is related to aging and brain development,but previous studies did not use the paradigm of backward inhibition to discuss the age characteristics of development and aging.This paper answers these questions through three studies and ten experiments.In study 1(Experiments 1 and 2),we investigated the effects of inhibition and retrieval on switching between univalent stimulus tasks with different difficulty.In Experiment 1,we used the arrow,number and letter stimuli to form easy and difficult difficulties,and investigated the Asymmetric Switch Cost when switching between the two difficulties of the three univalent stimuli.The results showed that Asymmetric Switch Cost occurs when switching between univalent stimulus tasks of different difficulty,and switching to easy tasks has greater switch cost.This result can be explained by Task-Set Inertia theory to some extent,but cannot be explained by Task-Set Reconfiguration theory.Experiment 2 changed the type of stimulus,and selected some common object stimulus pictures.All the stimuli were still univalent.According to the judgment of the perceptual and semantic characteristics of these stimuli,the tasks are divided into two types of difficulty,easy and difficult,and the difference of different switching conditions is compared.The result did not find the Asymmetric Switch Cost,but it can show that the inhibition and retrieval processes were involved in task switching.This result can be better explained by Task-Set Reconfiguration theory,but it cannot be explained by Task-Set Inertia theory.Study 2 combines backward inhibition with different retrieval difficulties through 4 experiments(Experiments 3 to 6),and manipulates inhibition and retrieval processes at the same time,explores their mode in task switch,and through manipulation of the form of cues,response difficulties,and the task types of perception and semantic judgment are used to explore the influence of these three factors on inhibition and retrieval modes in task switch.In the experiment,three kinds of retrieval difficulty were manipulated by the number of stimulus features and the different prompt information,and three task sequences of ABA switching,CBA switching and XAA repetition were designed(retrieval difficulty and task sequence are both internal variables of the subject),and n-2 repetition cost(the difference between the response time of ABA and CBA)were used to illustrate the inhibition ability;the difference between the reaction times of the three retrieval difficulties to illustrate the effect of retrieval;the interaction between retrieval difficulty and task sequence to illustrate the inhibitory mode under different retrieval difficulties.Experiment 3 found that the retrieval effect was obvious,and at the same time,it was found that under simple retrieval conditions,the effect of backward inhibition was obvious.Experiment 4 is based on Experiment 3,adding the response key prompts to the difficult retrieval cues to observe the effect of the cue form on the retrieval and inhibition mode.As a result,the change of the cue form does not affect the retrieval result mode,nor does it affect the backward inhibition under difficult retrieval condition.In Experiment 5,the response difficulty under the difficult retrieval condition was changed,and the subjects were required to derive the response key and make the reaction according to the reaction principle.The results showed that the change of response difficulty did not affect the results of the three retrieval conditions,nor did it affect the backward inhibition under the difficult retrieval condition.In Experiment 6,the perceptual judgment task in the previous experiment was changed to include both perceptual judgment task and semantic judgment task.The result showed perception and semantic judgment tasks affected the backward inhibition under the simple retrieval condition,but had no effect on the result of the retrieval.Study 3(Experiments 7 to 10)explored the development and aging trend of inhibition and retrieval modes in task switching by comparing the characteristics of backward inhibition under different retrieval difficulties of subjects in different ages.Experiments 7 to 9 selected children aged 8-9,10-11,and 12-13 as participants,respectively,to observe the development of their backward inhibition ability in easy and difficult(moderate retrieval condition in Exp.3)retrieval difficulties.The results showed that children in the two age groups 8-9 and 10-11 did not show backward inhibition under different retrieval difficulties.However,subjects in the 12-13 year old age group showed significant backward inhibition under difficult retrieval conditions.In the experiment 10,average age of 65 were selected as participants and it was found that no significant backward inhibition was found under the two retrieval difficulties.Based on the results of Study 1,Study 2,and Study 3,this study draws the following conclusions:1.The Asymmetric Switch Cost appears in the switching of univalent stimulus tasks of different difficulty,which supports the Task-Set Inertia theory,but not Task-Set Reconfiguration theory.When switching between the perceptual judgment task and the semantic judgment task of equivalent difficulty,there is no Asymmetric Switch Cost,which supports Task-Set Reconfiguration theory but not Task-Set Inertia theory.The results indicate only one theory cannot explain the results of this study.The interaction model of inhibition and retrieval can explain the switching process.that is,inhibition and retrieval participate in task switching together,and the effect of inhibition is affected by the difficulty of retrieval.2.Backward inhibition is affected by the retrieval difficulties.When the retrieval difficulty is simple,the effect of backward inhibition is obvious,and when the retrieval difficulty increases,the effect of backward inhibition is not obvious.3.Cues containing response keys and response difficulty did not affect the modes of inhibition and retrieval,while the types of perceptual and semantic judgment tasks affected the modes of inhibition,but not retrieval.4.The critical ages and trajectories of inhibition and retrieval are different.In terms of backward inhibition ability,children aged 8-11 years are still immature,children aged 12-13 years have matured,and the elderly aged over 65 years appear to decline.In terms of retrieval ability,children aged 8 were mature,and older people aged 65 and older showed no decline.