Differences Between Intentional And Unintentional Inhibition During Working Memory Retrieval

Executive function is a concept related to a group cognitive function corresponding to prefrontal cortex, and it has been regarded as a very important issue in the cognitive science and neuroscience. At present, there were many researches about the executive function, but the conception of it in those researches were inconsistent and confused. So, deeply studying every kind of executive functions would be helpful for us to understand and maste them comprehensively. After analyzing, inhibition was found to be a basic one type of them, categorized to intentional and unintentional Iinhibition. So this paper focused on the inhibition function.At the same time, there have been more and more researches concentrated on the working memory since it was a new concept. It has been found that working memory have crucial influence on many cognitive functions, including long-term memory retrieval. More importantly, most attention were paid to the encoding and processing in working memory, but little to working memory retrieval. Whereas, it has been found Memory Retrieval is not the duplication of Memory Encode in the long-term memory researches. It may be same to working memory. On the other hand, not only the encoding and processing but also the retrieval is necessary for the successfully conducting various cognitive task in the working memory. So the other focus of this paper is working memory retrieval.Then, are there some co-relation between the inhibition and working memory? Long-term memory researches have confirmed that retrieval inhibition as a special inhibition form is an important mechanism for accurate and deliberate retrieval~ And the retrieval inhibition can be categorized to be intentional and unintentional. The following paradigms were usually used, such as Directed Forgetting (DF), Retrieval Practice (Retrieval-induced Forgetting, RIF), Negative Priming(NP), Task Switching, Think/no-think, and so on. But few scholars had paid attention to working memory retrieval inhibition. Therefore, this paper co-relates the inhibition function with working memory retrieval by the retrieval inhibition. Four experiments and twelve sub-experiments were carried out to explore the cognitive mechanism differences between the intentional and unintentional inhibition during the working memory retrieval, and the revised directed forgetting paradigm and the revised retrieval induced forgetting paradigm were adopted.Experiment 1 consisted of two sub-experiments 1a and 1b, which explored the feasibility of the revised directed forgetting paradigm and the revised retrieval induced forgetting paradigm. In the results, the significant directed forgetting effect and retrieval induced forgetting effect were found during the process of working memory retrieval. And the best explanations to them were intentional and unintentional inhibition respectively. Experiment 2 and experiment 3 carried out by four sub-experiments to explore the influence of difficulty changes on the working memory retrieval intentional and unintentional inhibition respectively. The difficulty was controlled by absolute stimulus present time change and relative stimulus present time change. The results indicated that when the difficulty was controlled by the stimulus presented duration, the directed forgetting was neither affected by the difficulty of absolute nor relative duration change. The retrieval induced forgetting decreased and even disappeared as the difficulty increased either under the absolute or relative stimulus presented duration change. These results demonstrated that intentional inhibition and unintentional inhibition were functionally separated during the process of working memory retrieval. The stimulus presented duration had influence on unintentional retrieval inhibition, but no influence on intentional retrieval inhibition. The difficulty then was operated by category information induced interference level in the experiment 4. Similar to experiment 2 and 3, when the interference level was controlled by category information, directed forgetting declined with the increase of category information within or between the to-be-remembered items and to-be-forgotten items. This proved that the intentional inhibition during working memory retrieval was interference-independent, not sensitive to the difficulty induced by interferences. The retrieval induced forgetting declined with the decrease of category information and disappeared when different category information presented during study stage. This proved the unintentional inhibition during working memory retrieval was interference-dependent, highly sensitive to the difficulty changes induced by interferences.Thus it can be seen that the different experimental results' tendency of directed forgetting and retrieval induced forgetting under the same condition indicated that these two tasks reflected distinct cognitive mechanism, accordingly our summarization and distinction about the intentional and unintentional inhibition was valid and could be operated. And the fact that directed forgetting was insensitive to most of the condition in this study indicated the involvement of our intention could validly regulate the selective retrieval from working memory.