The Encoding And Retrieval Mechanism Of SPT Effect In Action Memory

Since Ebbinghaus explored memory by empirical methods, most researchersused words or static objects as experimental materials, which neglected the researchof overt actions. Until the early1980s, very few researchers had focused on theinteresting phenomenon that actions can enhance memory performance in everydaylife. In addition, it is established that free recall or recognition performance wouldbe better if participants were instructed to learn action phrases (e.g.,“open the book”)while performing the actions (subject-performed tasks, SPT) rather than learning thephrases by only listening or reading (verbal tasks, VT). That is, compared withverbal tasks, the superior memory performance in subject-performed tasks is knownas SPT effect.SPT effect was so significant and prevalent that it attracted great attention ofresearchers. Consecutively, the non-strategic processing theory, the multimodalencoding theory, the motor encoding theory and the episodic integration theory wereproposed to explain SPT effect. Briefly, the non-strategic encoding and the episodicintegration theory focused on the memory processing and explored SPT effect bycontrolling the level of strategic use during encoding and retrieving stages. On otherhand, the multimodal encoding theory and motor encoding theory focus on the samequestion from the perspective of processing contents. Even so, none of thementioned theories could completely explain the mechanism of SPT effect for theshortage of ignoring the unity of processing and contents. On the basis of theliteratures of action memory in the last three decades, the following four problemsare still existed: First, the characteristics of self-involvement during encoding havenot been investigated yet; Second, the automatic processing during action retrievalstill needs to be discussed; Third, the exploration of item-specific view deservesfurther analyzing; Fourth, the conclusions of non-strategic processing areinconsistent. Based on the above issues, we absorbed the key points of the four theoriesmentioned above, and put forward an integrated “involvement pop-out” model toexplain the SPT effect. Furthermore, the model contains two stages of encoding andretrieval which match the involvement component and pop-out component of themodel respectively. Item-specific processing (processing contents) is theintermediary factor of the two components which means that the self-involvementduring encoding strengthens the item-specific processing so as to determine thepop-out mechanism during retrieval. To be specific, the involvement duringencoding refers to self-involvement that includes three layers of implications. First,the self-involvement level under SPT is higher than that under VT. Second,self-involvement enhances item-specific processing. Last but not least, the level ofself-involvement is adjusted by experimental materials, as opposed to verbs, nounsinvolve much more self-involvement. With regard to retrieving aspect, the pop-outmechanism was determined by the item-specific processing mechanism duringencoding. In other words, the items which are at the middle or the end of the seriesposition could pop-out automatically, then these items will come into one’sconsciousness without active searching.In view of the "involvement pop-out" model, the R/K judgment paradigm, the"recall-recognition" paradigm and the directed forgetting paradigm are employed inthis study. Three parts of experiments were designed and the scores of recognitionand R/K judgment, the reaction time, free recall performance as well as the serialposition performance of “recall-recognition” were analyzed to gradually validate thehypotheses. The first two parts of experiments aim at verifying the indicators of the"involvement pop-out" model. Based on the available results, the third part ofexperiments are conducted to explore the effect of involvement and pop-outmechanism on the forgetting of SPT, so as to further validate and correct the"involvement pop-out" model from the perspective of forgetting.The first study was designed to verify the encoding segment of the model andexplored the three levels of self-involvement mechanisms. Specifically, experiment1applied the R/K judgment paradigm and took R (remembering) factor as adependent variable to evaluate the degree of self-involvement. The results showedthe reaction rates of R factor under SPT conditions are significantly better than that under VT conditions, which illustrates the higher level of self-involvement underSPT. We manipulated the variable of item-specific processing with differentinstructions to investigate the second implications of self-involvement inExperiment2. The results indicated that self-involvement improved the processinglevel of item-specific. The allocation of attention is affected by stimulatingproperties when performing actions. Therefore, different stimulus will lead todifferent degrees of self-involvement. In the field of action memory, noun-verbs arethe most common experimental materials, but verbs and nouns belong to differentstimulating properties. Experiment3examined the third implications ofself-involvement by controlling verb or noun clues, and the results illustrated thatcompared to verbs, self-involvement enhance the item-specific processing of nounsmore.The second study includes experiment4,5,6, to explore the "pop-out"mechanism in the model. Experiment4aims at investigating the pop-out mechanismof SPT effect by comparing the series position scores of "recall-recognition" testunder SPT or VT conditions, so as to testify the detailed pop-out items of SPTdirectly. The results showed that the middle and recent items under SPT wereretrieved automatically. Experiment5changed the way of retrieval, used categoryretrieval method and comparatively analyzed the "recall-recognition" performanceof SPT and VT. The results suggested that the pop-out mechanism is not caused bythe "later In first out" strategy. Besides, the results also probed that the pop-outmechanism is so stable that will not be affected by categorical recall. Experiment6manipulated the variable of item-specific processing during encoding with differentinstructions to make clear that the pop-out mechanism of SPT is due to theitem-specific processing during encoding as well as completely corroborate theintermediate variable of item-specific in the model. The results manifested that thepop-out mechanism during retrieval is determined by the item-specific processingduring encoding.The third study focus on the influence of involvement and pop-out on SPTforgetting for further validating and correcting the "involvement pop-out" modelfrom the view of memory forgetting. The results displayed that encoding conditioninfluenced directed forgetting effect of emotional words. Specifically, under the SPT condition, there was a directed forgetting effect for neutral and positive words butnot for negative words. Under the VT condition, all the type of words appeareddirected forgetting effect. In conclusion, both the item-specific processing caused byactions encoding before the presence of instructions and the inhibition effect ofnegative emotion on active suppression mechanism after the presence of instructions,were the influence factors that codetermined the phenomenon that negative emotionwas more difficult to be forgot under SPT.This model can explain the existing contradictions of SPT effect theoriesreasonably, complete and optimize the theoretical interpretation of SPT effect, so asto make contribution to clarify the mechanism of SPT effect and expand themultiple-system theoretical framework of memory.