定向遗忘中提取抑制的机制：成功提取引起抑制

两个实验采用无关材料考察了字表方式下提取诱发遗忘解释定向遗忘中提取抑制的可能性。在实验中,学习完两个字表后,对字表2 进行不同次数（0、1、3次）的提取练习以考察是否会增强定向遗忘效应以及定向遗忘效应是否随着提取练习次数的增加而增强。实验一中,字表2提取练习是要求被试回忆字表2项目,不给予线索提示。在实验二中,采用词干补笔测验的形式对字表2进行提取练习,词干补笔测验保证了对字表2项目的成功提取。研究结果发现,只有在实验二中对字表2的成功提取练习增强了定向遗忘效应,从而表明成功提取可以解释定向遗忘中的提取抑制     

Reducing negative emotional memories by retroactive interference

Because negative emotional memories are often disruptive, we conducted two experiments to reduce these memories by using a retroactive interference (RI) paradigm. In both experiments, participants were presented with highly negative pictures (List 1) followed by highly negative, moderately negative, or neutral pictures (List 2) or a rest period. Then, following a filler task, participants took a surprise free recall test, recalling pictures from List 1 in Experiment 1 and from both List 1 and List 2 in Experiment 2. In both experiments, recall of List 1 was reduced by List 2, indicating that RI was present. Furthermore, in Experiment 1, RI was similar between moderately negative and highly negative List 2 whereas in Experiment 2, RI was greater for highly negative List 2 than moderately negative List 2. These results showed that RI can be used to reduce negative emotional memories by making these memories inaccessible.     

Source‐monitoring accuracy across repeated tests following directed forgetting

The repeated recall of items from lists that participants were earlier instructed to either remember or to forget was examined in two experiments. RR participants (those instructed to remember both lists they were presented) tended to recall more List 1 items than FR participants (those instructed to forget the first list and to remember the second list). FR participants recalled more List 2 items than did RR participants, but only when directed to report those items (Experiment 1), not when directed to report items from both lists (Experiment 2). Participants experienced difficulty correctly reporting the list source of items they recalled and incorrect source recall increased across tests, showing hypermnesia. This later result underscores the need for caution when assessing the accuracy of information retrieved from multiple sources across repeated tests. Together, the data patterns provide support for the retrieval dynamics account of hypermnesia, the context‐change account of directed forgetting, and limited support for the retrieval inhibition view of directed forgetting.     

The role of retrieval practice in directed forgetting

Three experiments tested the possibility that retrieval-induced forgetting is responsible for directed forgetting with the list method. In Experiments 1 and 2, additional List 2 retrieval practice was given to determine whether this would increase directed forgetting. In Experiment 1 all items came from a single category, and in Experiment 2 unrelated words were used. In Experiment 3 additional List 2 study accompanied List 2 retrieval practice. There was no evidence that List 2 retrieval practice, with or without additional List 2 study, affected the magnitude of directed forgetting. It was argued that retrieval-induced forgetting could not account for these results. Accounts with greater viability include retrieval strategy disruption and a modified version of the dissociation hypothesis.     

Retrieval-induced forgetting in recall and recognition of thematically related and unrelated sentences

In three experiments, we assessed the effects of type of relation and memory test on retrieval-induced forgetting of facts. In Experiments 1 and 2, eight sets of four shared-subject sentences were presented for study. They were constructed so that half were thematically related and half were unrelated. A retrieval practice phase required participants to recall a subset of the studied sentences. In the final test, the participants were prompted to recall all the sentences (character cued in Experiment 1 and character plus stem cued in Experiment 2). The results showed that the retrieval-induced forgetting (RIF) effect was similar for thematically related and unrelated sentences, indicating that the presence of episodic relations among the sentences was sufficient to produce the effect. In Experiment 3, a recognition task was introduced and the RIF effect emerged in accuracy as well as in latency measures. The presence of this effect with item-specific cues is difficult to accommodate for noninhibitory theories of retrieval.     

Does the testing effect depend on presentation modality?

We examined whether the testing effect generalizes to an auditory presentation modality. Five lists of unrelated words (Experiment 1) and related words (Experiment 2) were presented to participants, half of whom studied them visually and half studied them auditorily. Participants in the study-only condition performed a short distractor task following lists 1–4, whereas those in the testing condition completed a short distractor task and then attempted to recall each list. Both groups were subsequently tested on List 5 and on all five lists 30 min later. In both experiments, we found a testing effect for both List 5 and for the final cumulative recall test. However, the effect did not interact with study modality, despite the fact that proactive interference was greater following auditory study. These results have important implications for educational practice, suggesting that initial testing is important for materials presented in auditory as well as visual formats.     

Repetition effects in directed forgetting: evidence for retrieval inhibition

Four experiments were conducted in support of a role for memory retrieval inhibition in directed forgetting. In each experiment, subjects were presented a list of words, some of which they were instructed to remember and some of which they were instructed to forget. After a recall test for all the words, the list was repeated. This time, however, all the words were presented with instructions that they be remembered. The improvement in recall from Trial 1 to Trial 2 was greater for the “forget” (F) words than for the “remember” (R) words. This difference was not due to a memorization-difficulty, item-selection effect (Experiment 2), a differential priority for rehearsal or output position given to the F items on Trial 2 (Experiment 3), or the greater number of F items left to be learned after Trial 1 (Experiment 4). Thus, the differential improvement from List 1 to List 2 for the F items was interpreted as a release of retrieval inhibition owing to the change in cue from forget to remember.     

Retrieval-induced forgetting occurs in tests of item recognition

Using the retrieval-practice paradigm (Anderson, R. A. Bjork, & E. L. Bjork, 1994), we tested whether or not retrieval-induced forgetting could be found in item recognition tests. In Experiment 1, retrieval practice on items from semantic categories depressed recognition of nonpracticed items from the same categories. Similar results were found in Experiment 2 in a more stringent source test for practiced, nonpracticed, and new items. These results conceptually replicate those of previous retrieval-induced forgetting studies done with cued recall (e.g., Anderson et al., 1994). Our findings are inconsistent with the hypothesis that item-specific cues during retrieval will eliminate retrieval interference in the retrieval-practice paradigm (Butler, Williams, Zacks, & Maki, 2001). We discuss our results in relation to other retrieval interference and inhibition effects in recall and recognition.     

The role of detection and recollection of change in list discrimination

In two experiments, we examined the importance of the detection and recollection of change for list discrimination. Two lists of pairs were presented, with the right-hand member being changed between lists for some pairs. Participants in Experiment 1 were instructed to explicitly indicate when they detected a change between pairs during the presentation of List 2, whereas participants in Experiment 2 were not instructed to do so. At the time of test, participants in both experiments were presented with a pair and asked whether it had been presented in List 2. Next, recollection of change was measured by asking whether the right-hand member of the pair was changed between the lists. The results from Experiment 1 revealed high correspondence between the detection of change during the presentation of List 2 and the recollection of change at the time of test. Consequently, change recollection at test can serve as a measure of earlier change detection, in combination with access to memory for change at the time of test. In both experiments, as compared to control conditions, proactive facilitation in list discrimination was observed when change was recollected, whereas proactive interference was observed when change was not recollected. These results were interpreted as showing that recursive reminding—bringing a List 1 pair to mind during the presentation of its changed List 2 pair—embeds memory for the earlier event into memory for the later event, and doing so preserves information about list membership.     

Retrieval-induced forgetting and mental imagery

In the present article, we present four experiments in which we examined whether mental imagery can initiate retrieval-induced forgetting. Participants were presented with word pairs (Experiments 1, 2, and 3) or narratives (Experiment 4) and then engaged in selective mental imagery about half of the details from half of the categories. The results indicated that mental imagery can produce the same pattern of impairment as retrieval practice (Experiment 1) and postevent questioning (Experiment 4). Additionally, mental imagery-invoked, retrievalinduced forgetting was found for category cued recall (Experiments 1, 3, and 4) and cued recall (Experiment 2); it was found to dissipate across a 24-h delay, but only when there was no pre-delay test (Experiment 3). Such retrieval-induced forgetting was also found for imagining from the first-person and third-person perspectives (Experiment 4). From these findings, we suggest that the underlying retrieval processes behind mental imagery can initiate retrieval-induced forgetting. The findings are discussed in terms of inhibitory processes.     

Context change and retrieval difficulty in the list-before-last paradigm

Using the "list-before-last" paradigm (Jang & Huber, Journal of Experimental Psychology: Learning, Memory, and Cognition, 34, 112-127, 2008; Shiffrin, Science, 168, 1601-1603, 1970), we examined whether the difficulty involved in retrieving a previously studied list affects the recall of the current list. Participants studied three lists (L1, L2, and L3), and between L2 and L3 study they either engaged in retrieval of L1 or solved math problems for the same duration of time. After L3 encoding, all participants recalled L2. We examined accurate recall of L2, intrusions from L3, and also the first-response function from L2 across all four experiments. In Experiments 1 and 2, retrieval difficulty was manipulated by presenting participants with variable numbers of letter cues for the L1 words, with some participants receiving more cues than others. In Experiment 1, L1 and L2 words shared the first two letters in common to create potential item interference, whereas in Experiment 2, they did not share common cues. In Experiments 3 and 4, we manipulated retrieval difficulty using a delay manipulation-L1 was encoded 1, 24, or 72?h prior to the session during which L2 and L3 were encoded. In Experiment 3, L1 retrieval involved a cued recall test, whereas in Experiment 4, it involved a free recall test. The results of all of these experiments showed that, as compared to solving math problems, retrieving L1 led to forgetting of L2, reduced intrusions from L3, and reduced first-response functions from L2. However, all of the dependent measures were invariant across the various manipulations of retrieval difficulty. We discuss the results in terms of the context-change interpretation of prior-list retrieval.     

Self-evaluation as a moderating factor of strategy change in directed forgetting benefits

In list method directed forgetting, instructing people to forget a studied word list usually results in better recall for a newly studied list. Sahakyan and Delaney (2003) have suggested that these benefits are due to a change in encoding strategy that occurs between the study of the first list and the study of the second list. To investigate what might mediate such strategy change decisions, in two experiments we induced bothforget and remember participants to evaluate their memory performance on the two lists. In Experiment 1, they were asked to explicitly recall the items from the first list before studying the second list. In Experiment 2, after the study of the first list, the participants provided a rapid aggregate judgment of learning. Evaluation eliminated the differences between the forget and remember groups for the second list in both experiments, because the remember group achieved recall levels comparable to those for the forget group. The role of performance evaluation in mediating directed forgetting benefits is discussed.     

PI and RI in serial learning as a function of environmental context

The influence of the environmental context upon serial learning was investigated in a PI design in Experiment 1 and an RI design in Experiment 2. Either one or four lists learned either before or after the critical list were used to manipulate PI or RI, respectively. Learning the critical list in the same room as the interference-inducing lists or in a different room provided the first context manipulation. The second context factor involved relearning the critical list in the same room as it was learned 24 hours earlier, or in a different one. In the PI study the early and middle thirds of the list were affected by context in original learning. In relearning, correct responses over the first two trials differed both as a function of number of prior lists learned and of original learning context. With RI, fewer trials to relearn were required by a condition involving facilitating context manipulations, relative to a neutral context, and a competing context condition was inferior. The results are largely consistent with predictions derived from the interference theory of forgetting and traditional associative learning theory.     

Immediate and sustained effects of planning in a problem-solving task

In 4 experiments, instructions to plan a task (water jugs) that normally produces little planning altered how participants solved the problems and resulted in enhanced learning and memory. Experiment 1 identified planning strategies that allowed participants to plan full solutions to water jugs problems. Experiment 2 showed that experience with planning led to better solutions even after planning was no longer required, whereas control participants showed little improvement. Experiments 3 and 4 showed that although the most recent planned solution could be recalled following a long filled retention interval, retroactive interference (RI) between successive problems resulted in much lower recall of earlier solutions. RI during plan generation could also explain participants' choice of depth-first planning strategies.     

The roles of encoding strategies and retrieval practice in test-expectancy effects

We investigated whether expectations for different kinds of memory tests induce qualitatively different encoding strategies. In Experiment 1, participants studied four lists of words and after each list completed a cued-recall test that contained either all semantic or all orthographic cues so as to build up an expectancy for receiving the same type of test for the fifth critical study list. To rule out that the test-expectancy effects in Experiment 1 were due to differences in retrieval practice, in Experiment 2, participants received three practice tests each for both cue-types. Participants’ test expectancy for all lists was induced by telling them before each list the type of cue they would receive for the upcoming study list. In both experiments, the critical test contained both expected and unexpected cues. In Experiment 1, participants who expected semantic cues had better recall to the semantic cues than to the orthographic cues and vice versa for those who expected orthographic cues. However, in Experiment 2, there was no effect of test expectancy. These findings suggest that the test-expectancy effects in Experiment 1 were due to more retrieval practice on the expected than unexpected tests rather than to qualitatively different test-expectancy-induced encoding strategies.     

Remembering can cause inhibition: retrieval-induced inhibition as cue independent process

Previous experiments have mostly relied on recall as a dependent measure to assess whether retrieval of information from memory causes inhibition of related information. This study aimed to measure this inhibition in a more direct way. In Experiment 1, it was shown that repeated retrieval of exemplars from a category resulted in longer recognition latencies to nonretrieved exemplars from that same category, compared with recognition latencies to control exemplars. Experiment 2 obtained the same pattern of results using a lexical decision task. This was the 1st time that retrieval-induced forgetting was demonstrated on an implicit test of memory. To exclude noninhibitory explanations of the data, the exemplars were presented in both experiments without their categories as cues.     

The testing effect in free recall is associated with enhanced organizational processes

In two experiments with categorized lists, we asked whether the testing effect in free recall is related to enhancements in organizational processing. During a first phase in Experiment 1, subjects studied one list over eight consecutive trials, they studied another list six times while taking two interspersed recall tests, and they learned a third list in four alternating study and test trials. On a test 2 days later, recall was directly related to the number of tests and inversely related to the number of study trials. In addition, increased testing enhanced both the number of categories accessed and the number of items recalled from within those categories. One measure of organization also increased with the number of tests. In a second experiment, different groups of subjects studied a list either once or twice before a final criterial test, or they studied the list once and took an initial recall test before the final test. Prior testing again enhanced recall, relative to studying on the final test a day later, and also improved category clustering. The results suggest that the benefit of testing in free recall learning arises because testing creates retrieval schemas that guide recall.     

Testing enhances subsequent learning in older but not in younger elementary school children

In adults, testing can enhance subsequent learning by reducing interference from the tested information. Here, we examined this forward effect of testing in children. Younger and older elementary school children and adult controls studied four lists of items in anticipation of a final cumulative recall test. Following presentation of each of the first three lists, participants were immediately tested on the respective list, or the list was re‐presented for additional study. Results revealed that, compared to additional study, immediate testing of Lists 1–3 enhanced memory for the subsequently studied List 4 in adults and older elementary school children, but not in younger elementary school children. The findings indicate that the forward effect of testing is a relatively late‐maturing phenomenon that develops over middle childhood and is still inefficient in the early elementary school years. Together with the results of other recent studies, these findings point to a more general problem in young children in combating interference.     

Influences of environmental context on the recency effect in free recall

A total of 208 undergraduate participants incidentally encoded a list of seven pairs of familiar words in two experiments. A 30-sec calculation task was imposed before and after each pair was encoded. Participants received a free recall test 24 h (Experiment 1) or 10 min (Experiment 2) after the encoding session, under conditions in which the original environmental context was reinstated or not. The environmental context was manipulated in terms of the combination of the physical features of the room, the subsidiary task conducted, the experimenter (Experiment 1), or background music (Experiment 2). A recency effect appeared when the original environmental context was reinstated in both experiments, even though the IPI/RI ratio was too small to produce recency effects according to the ratio rule. The results imply that the environmental context should be taken into account for the recency effect.     

Episodic generation can cause semantic forgetting: Retrieval-induced forgetting of false memories

In two experiments, we tested whether false recognition and false recall were prone to retrieval-induced forgetting, using the retrieval practice paradigm (Anderson, Bjork, & Bjork, 1994). Participants encoded lists of cue-target word pairs associated with a nonpresented, critical theme word and then engaged in retrieval practice for half of the word pairs from half of the lists. As expected, unpracticed targets from practiced lists were recognized (Experiment 1) and recalled (Experiment 2) less well than those from unpracticed lists. In addition, false recognition and false recall of critical items associated with practiced lists was lower than false recognition and false recall of items associated with unpracticed lists. We argue that false memories are prone to inhibitory mechanisms engendered by the retrieval practice paradigm. The results are consistent with the claim that semantically activated critical themes interfere with the episodic retrieval of list words and that inhibition decreases the activation level of these interfering memory representations during retrieval practice.