Abstract: Intuition suggests that “two heads together are better than two heads apart” when completing cognitive tasks, particularly problem solving. However, this does not appear to be the case for memory tasks. Researchers demonstrated that, during retrieval, individuals working together as a collaborative group performed much more poorly than did the same number of people recalling individually (nominal group). This phenomenon is called collaborative inhibition effect. There have been a number of studies on this topic since it was found two decades ago. Researchers have also given models to explain this effect. Psychologists suggested that collaborative inhibition might be due to the single theory such as retrieval inhibition mechanism, which suggests that when an individual engages in recall in a collaborative setting, relating the results of that recall to other group members might cause both the speaker and the listener to forget non-recalled materials, or retrieval disruption mechanism, which states that each individual’s idiosyncratic organization of overlapping information is disrupted during collaborative recall phases. However, there are growing evidences that it is inconsistent with the single theory account, suggesting that multiple mechanisms are needed to be explored underlying collaborative inhibition. To identify the contributions of retrieval inhibition and retrieval disruption underlying collaborative inhibition, the current study explored how the encoding mode and the encoding order consistency influence collaborative inhibition. Experiment 1 adopted a survival-processing paradigm to investigate whether retrieval inhibition plays a role in collaborative inhibition. In this experiment, 108 participants that compose 36 groups were randomly assigned to the survival-processing condition or non-survival-processing (control) condition. After the encoding phase, each group finished a group (collaborative or nominal) recall test. The results obtained here suggested that survival-processing condition and non-survival-processing condition both showed collaborative inhibition effect; but this deficit was attenuated in survival-processing condition, which means the encoding modes influenced the magnitude of collaborative inhibition, that indicated the retrieval inhibition mechanism plays a role in collaborative inhibition. Experiment 2 used associative memory training method to investigate whether retrieval disruption could influence collaborative inhibition. Another 120 participants were volunteered in this experiment. Half of the groups encoding items in the same order and the other half was not, both of whom were taught to encoding the materials with associative memory method in two weeks. The results of Experiment 2 showed that after the specific memory training, participants that learned items in the same order showed no collaborative inhibition, while participants that learned items in the different order showed classic collaborative inhibition. These results suggested that the encoding order consistency influence the magnitude of collaborative inhibition, which confirm the role of retrieval disruption mechanism underlying collaborative inhibition. Many results demonstrated that single theory (either retrieval inhibition or retrieval disruption mechanism) might be the mechanism of collaborative inhibition. However, the current results demonstrated that both retrieval inhibition and retrieval disruption mechanisms underlying collaborative inhibition. These results suggested that, compared to single theory, multiple mechanisms are more suitable to explain collaborative inhibition. Based on the above results, we discussed the mechanisms underlying collaborative inhibition. In addition, we give some important points to the future studies. Above all, collaborative inhibition may have multiple bases—in addition to retrieval inhibition, retrieval disruption also plays a role.

Key words: collaborative inhibition, retrieval inhibition, retrieval disruption, encoding mode, encoding consistency

摘要： 协作抑制是指小组提取的信息量比等量个体单独提取的信息总量要少。对于协作过程降低小组成员提取潜能的机制解释，不同研究之间仍有争论。本研究实验1使用经典的生存加工范式，实验2使用联想记忆训练法，分别考察编码加工方式和编码相似性对协作提取成绩的影响，从而检验提取抑制和策略破坏机制是否能分别影响协作抑制。研究结果表明，被试在生存和非生存（愉悦度和自我经历）加工条件下都出现协作抑制现象，而生存加工条件下的协作抑制量显著小于非生存条件；在使用联想记忆训练法之后，相同学习顺序组没有出现协作抑制，而不同学习顺序组出现了经典的协作抑制。本研究结果为协作抑制的可能存在的多机制解释提供了证据。

关键词: 协作抑制, 提取抑制, 策略破坏, 编码加工方式, 编码相似性