线索强度对提取练习效应的影响机制:来自ERP的证据

How Does Cue Strength Affect The Retrieval Practice Effect: Evidence from ERPs

运用事件相关电位技术,探讨提取练习和精细加工在不同线索强度上加工方式的异同。结果显示:强线索词对下,二者的相继记忆效应未出现显著性的分离,出现500~700ms额叶、中央分布的模式;弱线索词对下,二者的相继记忆效应出现分离,在提取条件500~700ms、700~1000ms观察到与晚期顶叶成分相似的相继记忆效应,而精细加工下并没有。结果表明:提取强线索词时个体的加工方式与精细加工类似,提取弱线索词时与精细加工不同,支持情境背景理论。

The retrieval practice effect refers to the theory that memory retrieval on one or more tests improves memory retention better than restudying or elaborative study among certain amount of time. Up to now, retrieval practice effect has been observed in a variety of materials and different subjects. It is worth noting that researchers have found that cue strength can affect the retrieval practice effect when using cue target word pairs as research materials. Unfortunately, it is still not clear as to how cue strength affects it. To explore the mechanism of cue strength affecting the retrieval practice effect, the present study compared the electrophysiological responses of different learning strategies in different cue strength learning materials.We recruited 40 participants(male: 14, female: 16, age range: 19~26 years, average age: 22.8 years), using a mixed experimental design of 2(learning condition: retrieval practice, elaborative study) × 2(cue strength: weak, strong). The experiment used the classical paradigm for the retrieval practice effect(including three distinct phases: study phase, initial retrieval phase, and a final test phase after a delay of one week). First, During the study phase, participants were instructed to learn and memorize the cue target word pairs with different cue strengths. Secondly, during the initial retrieval phase, participants were asked to use two learning strategies to learn the cue target word pairs that were presented in study phase. Lastly,during final test phase, participants were asked to complete the old and new discrimination test. In addition, the EEG data of the participants in the initial retrieval phase were recorded.The behavioral data showed the influence of cue strength on retrieval practice effect. In the weak cue strength group, the performance of the retrieved practiced cue target word pairs in the final test was significantly better than the elaborative studied cue target word pairs(retrieved practiced items had higher discrimination index-d’). However, in the strong cue strength group, there was no significant difference in the performance of the two learning conditions in the final test. Event-related potential(ERP) data showed that there was a significant difference between the subsequent memory effect(SME) of the two learning conditions when learning weak-cue-strength word pairs. In the three selected time windows, it was always observed that the main effect of learning condition was significant or the interaction effect between learning condition and other factors was significant, and SME was similar to Late Parietal Component(LPC) in the retrieval practice condition. In contrast, when learning strong-cue-strength word pairs, the two learning conditions had similar SME. We found that in 300~500ms and 500~700ms, there was no significant main effect of learning condition or interaction effect with other factors. Although there was a significant main effect of learning condition in 700~1000ms, there was still no SME.In the current study, there is evidence that whether to retrieve episodic context is the key to retrieval practice effect. When retrieving the strong-cue-strength word pairs, it is precise because the individual does not retrieve episodic context, but uses the cognitive processing similar to the elaborative study, which affects retrieval practice effect. In addition, this study once again supports the Episodic Context Account.