The promotion effect of automatically activated long-term associative representation on working memory

Research has demonstrated that long-term memory can improve working memory processing. However, these studies only used item memory as a representation of long-term memory. Associative memory also plays a critical role in long-term memory. An investigation revealed that associative representation impeded working memory, in contrast to the outcomes generated by item memory. It is possible that the participants were unable to generate activated associative memory from unrelated paired items. The purpose of this study was to explore how the activation of associative representations in long-term memory, through semantic relations, impacts working memory processing. This study is comprised of three experiments. For Experiment 1, twelve pairs of semantic association pictures were required to be memorized for long-term storage prior to the working memory task, whereas the other twelve pairs did not require pre-memorization. During the working memory array, images were presented in pairs (associative condition) or separately (independent condition) for 500 ms. Following a 1000 ms interval, participants had to decide whether the probe item was identical to the memory array. Experiment 2 was similar to Experiment 1, except that the memory array was presented for either 500 ms or 1000 ms and all items required memory training to be completed the day before. In Experiment 3, the variable of time was removed and two items were included as benchmarks. Additionally, Electroencephalogram (EEG) Alpha power was recorded and analyzed. Experiment 1 revealed that the accuracy and memory capacity of the associative condition were significantly higher than those of the independent condition, suggesting that the automatic activation of the association representation in long-term memory enhanced the performance of the current working memory task. Experiment 2 showed that the associative condition had higher accuracy and memory capacity than the independent condition for both the 500 ms and 1000 ms presentation-time conditions. Experiment 3 demonstrated that participants in the associative condition had better working memory capacity and accuracy than those in the independent condition. EEG data showed that alpha power was greater in the associative condition than in the independent condition during the maintenance phase. The findings from the experiments demonstrated that the associative condition had a higher working memory capacity than the independent condition. In conclusion, activating long-term memory associations can enhance working memory processing, regardless of the duration of encoding. The benefit of associative representation on working memory stems from its ability to aid in the storage and manipulation of information, rather than the simplification effect of compression.