Research On The Coding Mechanism Of Directed Forgetting

Does purposeful forgetting require cognitive effort? There are two main viewpoints: one is that directed forgetting does not require effort;the other is that directed forgetting is a process that requires more cognitive effort than memory.Based on previous studies,this study intends to adopt the item method directed forgetting paradigm to further explore the controversy between these two theories.This study includes three experiments: experiment 1,experiment 2 and experiment3.In addition to the encoding tasks of memory and forgetting,each participant also need to complete the detection task in this stage.In experiment 1,the encoding task was consisted of "remembering","forgetting" and "naming".The detection task itself was not taken as an independent variable,but the time interval between the detection task and the encoding task was taken as an independent variable.Three intervals were selected: 750 ms,1150ms and 1750 ms.The dependent variable of the experiment is the response time of the detection task,and the cognitive effort of different encoding tasks is examined by the response time of the detection task(this dependent variable is used in all three experiments in this study).The results suggested that the directed forgetting effect was significant,and there was no difference in the detection response of "remembering" and "forgetting" encoding,but the detection response of "naming" encoding was significantly faster than "remembering" and "forgetting" encoding.The main effect of time interval was significant,the shorter the time was,the longer the detection of stimulus response time was.The second experiment is similar to the first,which also takes the encoding mode and interval time as independent variables.In order to distinguish the difference between "naming" and "remembering",and compare with the encoding level of "none",two sub experiments were designed in experiment 2.Each experiment was encoded with "remembering","forgetting","none" and " naming ","forgetting","none".The results showed that the directed forgetting effect was significant,and the response time of "none" encoding was significantly longer than that of "remembering","forgetting" and "naming",but there was no significant difference between "remembering" and "forgetting".The main effect of interval time was significant.The shorter the interval time was,the slower the response time was.Experiment 2-2 showed significant interaction: when the time interval was extended to 2350 ms,the encoding of "forgetting" and "none" tended to be completed or finished,and the detection reaction time was similar,but the encoding of "naming" may be completed faster,so the detection reaction time was significantly faster than the former two.In experiment 3,in addition to the encoding and the time interval between two independent variables,including detection of stimulus type.Detected stimuli were divided into three types: original code words,new words and symbols.The subjects performed the encoding operations of "remembering","forgetting" and "none",and then selected the response to the detection stimulus(the color of the word).The results showed that there was no significant difference in the detection response time between "remembering","forgetting" and "none",but the type of detection stimulus significantly affected the detection response time after encoding.In addition,the main effect of the interval time was also significant,which was consistent with Experiment 1 and Experiment 2:The longer the interval time was,the faster the response time of the detection task was.In conclusion,the following conclusions were drawn in this study.First,there was no significant difference in the cognitive resource consumption between remembering and forgetting items in the encoding stage of directed forgetting,but both of them required cognitive effort.Second,the shorter the time interval of the detection task in the encoding stage was,the longer the response time of the detection task was,indicating that whether the operation was remembered or forgotten,the encoding was carried out in a relatively short time.Third,the different detection tasks did not affect the experimental conclusions.In general,although the conclusion of this study was significant,given the limitations of this study,future research will need to further investigate the accuracy of experimental design of “ none ” encoding,extend the interaction between different detection tasks and encoding methods,try to include noncognitive factors to solve the controversial issue,and use more accurate experimental means to determine the specific time process of encoding.