| The levels of processing effect refer to the fact that deeper semantic processing during encoding is more helpful to subsequent memory retrieval than shallow perceptual processing.Previous studies have found that the LoP effect is stable in the item memory,and research on the LoP impact of associative memory is relatively rare.However,the manipulation of the levels of processing in these studies rested more on individual items than on inter-item relationships and did not offer perspectives on integration.Its processing mechanism is not fully clear.In addition,some studies have found that the levels of processing also moderate the effect of directed forgetting of item memory.But there is a relative gap in research on the mechanism of the stories of processing on directed forgetting of associative memory,and the underlying neural mechanism is still unclear.Therefore,we used different types of associative materials to separate perceptual and semantic processing in the context of directed forgetting to explore the effect of the levels of processing on directed forgetting of associative memory and its potential neural mechanism through four experiments.Experiment 1 aimed to investgate the influence of the levels of processing on directed forgetting of word-word associative memory.The experiment adopted a 2(levels of processing: high,low)× 2(instruction: remember,forget)mixed design.The levels of processing was the between-subjects variable.The dependent variables were recognition accuracy,reaction time and false rate of rearranged.The results showed that there was LoP effect in word-word associative materials.Directed forgetting effect was stable in the high and low processing level.In addition,the results showed that the associative recognition of word-word associative materials was more dependent on the recall processing.In Experiment 2,meaningless abstract shapes were used as stimuli,and experimental design and experimental procedure were the same as Experiment 1.The experiment aimed to investgate the influence of the levels of processing on directed forgetting of shape-shape associative memory.The results show that there was LoP effect in shape-shape associative materials.The directed forgetting effect was only present in the high processing level,but not in the low processing level.According to the results of false alarm rate of rearranged,the associative recognition of shape-shape materials is more dependent on familiarity processing.In experiment 3,between-domain inter-item word and shape associative materials were used as stimuli,and experimental design and experimental procedure were the same as Experiment 1 and Experiment 2.The results showed that LoP effect also existed stably in between-domain inter-item associative memory.However,unlike Experiment1 and Experiment 2,directed forgetting effect did not appear in the high and low processing level.According to the results of false alarm rate of rearranged,the associative recognition of word and shape associative materials is more dependent on recall processing.Experiment 4 explored the processing mechanisms of directed forgetting of between-domain inter-item associative memory with the help of ERP technology.Its experimental design was the same as experiment 3.The EEG results showed that the high processing level had a stronger cognitive association with the encoding of word and shape material than the low processing level.In the extraction phase,the association recognition of the two conditions mainly depended on familiarity rather than recall.EEG results of directed forgetting are consistent with behavioral results: The instruction to "forget" did induce active inhibition of the associative material,but the directed forgetting effect at both high and low processing levels was not highlighted for the relevant components.This study draws the following conclusions:(1)LoP effect exists stably in different types of associative recognition.At low processing level,the associative memory integration tends to be consistent,while at high processing level,the associative memory integration is affected by material significance.(2)The role of familiarity and recall in supporting associative memory varies dynamically among different types of associative materials.The associative recognition of word-word material and word & shape associative material are more dependent on the process of recall.This further support for the unitization hypothesis of associative recollection.(3)The directed forgetting of associative memory was influenced by levels of processing and material characteristics,and selective recall and inhibitory control were involved together. |
