Priming guesses on a forced-recall test

The forced-recall paradigm requires participants to fill all spaces on the memory test even if they cannot remember all the list words. In the present study, the authors used that paradigm to examine the influence of implicit memory on guessing--when participants fill remaining spaces after they cannot remember list items. They measured explicit memory as the percentage of targets that participants designated as remembered from the list and implicit memory as the percentage of targets they wrote but did not designate as remembered (beyond chance level). The authors examined implicit memory on guessing with forced recall (Experiment 1), forced cued recall with younger and older adults (Experiment 2), and forced free and cued recall under a depth-of-processing manipulation (Experiment 3). They conclude that implicit memory influences guesses of targets in the forced-recall paradigm.     

部分线索效应中的记忆监控

通过三个实验,利用学习时间分配作为指标,考察了学习者对部分线索效应记忆监控的状况。实验1考察被试在单次学习条件下的学习时间分配情况,结果发现被试在两种条件下所使用的学习时间没有明显差异。这说明在一次学习后被试还不能对部分线索的消极作用进行有效控制。实验2中,经过多次学习后,被试在部分线索条件下使用了更多的学习时间。实验3在自控步调学习前加入回溯性任务难度判断任务,结果发现经过一次学习,部分线索组和自由回忆组的判断值虽无显著差异,但部分线索组的自控步调学习时间显著长于自由回忆组,并且其回忆成绩也显著提高,说明回溯性任务难度判断过程本身是学习时间分配的制约因素。研究说明,为了加速主体对部分线索的消极影响的控制,引导主体对学习任务进行难度判断是一种有效的手段。     

Social processing improves recall performance

One recent theory (Dunbar, 2003) has highlighted the importance that processing social information might have had on the evolution of human cognition. Based on an analysis of that theory, researchers predicted that processing information in a social manner would improve recall performance in comparison with nonsocial processing. In order to test this prediction, three experiments were conducted in which participants studied 30-item word lists that were composed of common character traits (Experiment 1) or common category exem-plars (Experiments 2 and 3). Next, participants reviewed 5 list items that were purportedly recalled by either a group member or the computer. Finally, after a brief distractor task, participants were asked to complete an individual recall test for all of the items on the original 30-item list. Of primary interest was recall performance for the list items that were purportedly recalled by either another participant or the computer. We observed that recall performance for list items purportedly recalled by another participant was superior to that for items that were recalled by the computer.     

An item gains and losses analysis of false memories suggests critical items receive more item-specific processing than list items

In a repeated testing paradigm, list items receiving item-specific processing are more likely to be recovered across successive tests (item gains), whereas items receiving relational processing are likely to be forgotten progressively less on successive tests. Moreover, analysis of cumulative-recall curves has shown that item-specific processing produces a slower, but steadier rate of recall than relational processing. The authors relied on these findings to determine the type of processing that both list items and critical lures receive in the Deese-Roediger-McDermott false memory procedure. The first 2 experiments revealed that critical lures produced more item gains, but only the list items resulted in a decrease in item losses across successive tests. The critical lures also produced slower but steadier cumulative recall. In Experiments 3 and 4, the critical items were physically presented during study, which resulted in the lures producing progressively fewer losses across successive tests. The authors concluded that critical items receive more item-specific processing than list items but that unless they are presented in the list, they do not become part of participants' organized retrieval scheme.     

The effect of the length of to-be-remembered lists and intervening lists on free recall: a reexamination using overt rehearsal

In 3 experiments, the authors investigated the effects of to-be-remembered (TBR) and intervening list length on free recall to determine whether selective rehearsal could explain the previous finding that recall was affected only by TBR list length. In Experiments 1 (covert rehearsal) and 2 (overt rehearsal), participants saw 5- and 20-word lists and had to recall the list prior to that last presented list. In Experiment 3, either 1 or 2 lists were presented, and recall of TBR list was postcued. Recall proportion decreased with increased TBR list length. Moreover, the authors found extended recency effects when recall was replotted by when words were last rehearsed (Experiments 2 and 3) and an effect of intervening list length when rehearsal was reduced (Experiment 3).     

Limits of the retrieval-inhibition construct: list segregation in directed forgetting

The authors hypothesized that retrieval inhibition in list method directed forgetting could be improved by presenting a task that maximized the segregation step of the retrieval-inhibition process. In Experiment 1, they presented lists of semantically related words in a list method directed-forgetting task to maximize retrieval inhibition. Contrary to predictions, this manipulation eliminated the directed-forgetting effect. The authors further investigated the results of Experiment 1 in Experiments 2 and 3 by manipulating recall instructions and by presenting lists that contained both a categorized and an unrelated list-half. They found directed-forgetting effects for semantically related word lists when participants were asked to recall only the TBR (to-be-remembered) items but not when participants were asked to recall both the TBF (to-be-forgotten) and TBR items. They also found that directed-forgetting effects were not produced when categorized items were presented in the 1st list.     

Limits of the Retrieval-Inhibition Construct: List Segregation in Directed Forgetting

The authors hypothesized that retrieval inhibition in list method directed forgetting could be improved by presenting a task that maximized the segregation step of the retrieval-inhibition process. In Experiment 1, they presented lists of semantically related words in a list method directed-forgetting task to maximize retrieval inhibition. Contrary to predictions, this manipulation eliminated the directed-forgetting effect. The authors further investigated the results of Experiment 1 in Experiments 2 and 3 by manipulating recall instructions and by presenting lists that contained both a categorized and an unrelated list-half. They found directed-forgetting effects for semantically related word lists when participants were asked to recall only the TBR (to-be-remembered) items but not when participants were asked to recall both the TBF (to-be-forgotten) and TBR items. They also found that directed-forgetting effects were not produced when categorized items were presented in the 1st list.     

Falsely recalled items are rich in item-specific information

Current theorizing suggests that critical lures in the Deese/Roediger-McDermott (DRM) procedure are often falsely remembered because they have received considerable relational processing (e.g., spreading activation or encoding of gist information). We used a repeated-testing paradigm to assess the amount of item-specific and relational processing given to the list items and the critical lures. Research has shown that items receiving item-specific processing are more likely to be recovered across successive tests. They are also output more slowly but more steadily throughout the recall period. In two experiments, we manipulated the processing performed on list items and then used item gains and cumulative recall curves to assess the amount of item-specific an drelational information encoded for both list items and lures. The results suggest that increasing the relational processing of list items increased item-specific processing of lures, whereas increasing item-specific processing of list items decreased item-specific processing of lures. We conclude that critical lures are typically rich in item-specific information, relative to list items.     

Variation in working memory capacity and intrusions: Differences in generation or editing?

The current study explored the reason for the relation between individual differences in working memory capacity (WMC) and intrusions in free recall. High and low WMC individuals were tested in standard delayed free recall and externalised free recall in which participants recalled everything that came to mind. Additionally, in externalised free recall participants were instructed to press a key for each item that they knew was an intrusion. In delayed free recall, low WMC individuals recalled fewer correct items and more previous list and extralist intrusions than high WMC individuals. In externalised free recall, differences only arose in previous list intrusions. Furthermore, in externalised free recall it was found that low WMC were less likely to identify both types of intrusions than high WMC individuals. It is argued that the reason low WMC individuals recall more intrusions than high WMC in free recall is due to differences in both generation and editing abilities.     

The emergence of strategic knowledge activation in categorical clustering during retrieval

Elementary school children's free recall clustering has recently been explained as an automatic by-product of their developing knowledge base. In contrast, it is claimed that as children get older they become aware of the usefulness of category organization as a memory strategy that enables them to strategically activate category knowledge even during retrieval. To test this hypothesis an experimental procedure was developed where Ss first had to learn items in a noncategorical order to the criterion of two perfect serial recall trials. After a 12- to 15-min retention interval Ss unexpectedly received either serial or free recall (or--in Experiment 1--cued recall) instructions. In three experiments with second and fourth graders it was shown that (1) fourth graders' recall exceeded that of second graders only in the free, but not in the serial (or cued), recall condition, (2) higher levels of clustering were observed for fourth graders in the free recall condition, and (3) the grade effect on free recall data was eliminated when the influence of metamemory and categorical clustering statistically was partialled out (Experiments 1 and 3). This pattern of results proved robust against variants in which a metamemory question was asked or omitted prior to recall (Experiment 2) and manipulations in which age differences in categorical knowledge were minimized (Experiment 3). The results were interpreted as demonstrating fourth graders' strategic competence in activating category knowledge during retrieval and second graders' automatic knowledge activation.     

Temporal associations and prior-list intrusions in free recall

When asked to recall the words from a just-presented target list, subjects occasionally recall words that were not on the list. These intrusions either appeared on earlier lists (prior-list intrusions, or PLIs) or had not appeared over the course of the experiment (extra-list intrusions). The authors examined the factors that elicit PLIs in free recall. A reanalysis of earlier studies revealed that PLIs tend to come from semantic associates as well as from recently studied lists, with the rate of PLIs decreasing sharply with list recency. The authors report 3 new experiments in which some items in a given list also appeared on earlier lists. Although repetition enhanced recall of list items, subjects were significantly more likely to make PLIs following the recall of repeated items, suggesting that temporal associations formed in earlier lists can induce recall errors. The authors interpret this finding as evidence for the interacting roles of associative and contextual retrieval processes in recall. Although contextual information helps to focus recall on words in the target list, it does not form an impermeable boundary between current- and prior-list experiences.     

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.     

Greater priming for previously distracting information in young than older adults when suppression is ruled out

The use of previously distracting information on memory tests with indirect instructions is usually age-equivalent, while young adults typically show greater explicit memory for such information. This could reflect qualitatively distinct initial processing (encoding) of distracting information by younger and older adults, but could also be caused by greater suppression of such information by younger adults on tasks with indirect instructions. In Experiment 1, young and older adults read stories containing distracting words, which they ignored, before studying a list of words containing previously distracting items for a free recall task. Half the participants were informed of the presence of previously distracting items in the study list prior to recall (direct instruction), and half were not (indirect instruction). Recall of previously distracting words was age-equivalent in the indirect condition, but young adults recalled more distracting words in the direct condition. In Experiment 2, participants performed the continuous identification with recognition task, which captures a measure of perceptual priming and recognition on each trial, and is immune to suppression. Priming and recognition of previously distracting words was greater in younger than older adults, suggesting that the young engage in more successful suppression of previously distracting information on tasks in which its relevance is not overtly signaled.     

Inter- and intra-individual variation in immediate free recall: an examination of serial position functions and recall initiation strategies

Serial position functions in immediate free recall have been historically noted for their bowed shape, where items presented at the beginning (primacy) and end (recency) of a list are better remembered than those presented in the middle. While extensive work has examined these effects, researchers typically ignore the systematic differences among individuals that likely contribute, but are lost when using an aggregate function. In the current study, inter- and intra-individual differences in serial position functions and differences in recall strategies were examined. Participants performed a free recall task on multiple lists. Three groups of participants were derived based on the relative profiles in their serial position functions. These groups differed in the extent that they output mainly primacy items, recency items, or both primacy and recency items. Performance on immediate free recall and on cognitive ability tasks was compared between these three groups. Systematic inter- and intra-individual variation in recall strategies led to differential profiles of performance in immediate free recall, which was also related to the additional cognitive ability measures. Performance on a task can be due to the utilisation of a variety of control processes that emphasise various components of that task over other components.     

Isolation of massed- and distributed-practice items

In four experiments, massed-practice (MP) or distributed-practice (DP) items were isolated from other items in a list presented either visually or auditorially for free recall. For three independent groups, the first, second, or both presentations of an item were isolated. Locus of isolation had a marginal influence on recall. When MP items were isolated, they were recalled better than DP items. Isolating the DP items enhanced the MP-DP effect. The results are congruent with the idea that the MP-DP effect in free recall results, in part, from differential rehearsal.     

Episodic inhibition

Six experiments examined the proposal that an item of long-term knowledge can be simultaneously inhibited and activated. In 2 directed forgetting experiments items to-be-forgotten were found to be inhibited in list-cued recall but activated in lexical decision tasks. In 3 retrieval practice experiments, unpracticed items from practiced categories were found to be inhibited in category-cued recall but were primed in lexical decision. If, however, the primes and targets in lexical decision were taken directly from the study list, inhibition was observed. Finally, it was found that when items highly associated with a study list were processed in between study and test, no inhibition in recall was present. These, and a broad range of other findings, can be explained by the concept of "episodic inhibition," which proposes that episodic memories retain copies of semantic knowledge structures that preserve patterns of activation/inhibition originally generated in those structures during encoding. ((c) 2006 APA, all rights reserved).     

Generation effects in free recall: further support for a three-factor theory

A framework is presented that helps explain and predict generation effects in free recall (for between-subjects manipulations of generating vs. reading). When the targets share common features and when that shared information is salient to subjects, subjects will exploit that information to help generate the target items. This produces more relational processing among the targets (relative to reading), enhancing free recall. Consistent with this idea, when shared information (among targets) was salient, generation effects in free recall were found under encoding conditions that can disrupt generation effects in cued recall (e.g., pairing targets with unrelated cues). Further, within the same list, generation effects emerged in free recall for targets that were processed after shared information became evident but not for targets processed prior to the availability of the shared information. In recognition, generation effects were found for targets regardless of when they were processed.     

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     

When false memories do not occur: not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

Value-based modulation of memory encoding involves strategic engagement of fronto-temporal semantic processing regions

A number of prior fMRI studies have focused on the ways in which the midbrain dopaminergic reward system coactivates with hippocampus to potentiate memory for valuable items. However, another means by which people could selectively remember more valuable to-be-remembered items is to be selective in their use of effective but effortful encoding strategies. To broadly examine the neural mechanisms of value on subsequent memory, we used fMRI to assess how differences in brain activity at encoding as a function of value relate to subsequent free recall for words. Each word was preceded by an arbitrarily assigned point value, and participants went through multiple study–test cycles with feedback on their point total at the end of each list, allowing for sculpting of cognitive strategies. We examined the correlation between value-related modulation of brain activity and participants’ selectivity index, which measures how close participants were to their optimal point total, given the number of items recalled. Greater selectivity scores were associated with greater differences in the activation of semantic processing regions, including left inferior frontal gyrus and left posterior lateral temporal cortex, during the encoding of high-value words relative to low-value words. Although we also observed value-related modulation within midbrain and ventral striatal reward regions, our fronto-temporal findings suggest that strategic engagement of deep semantic processing may be an important mechanism for selectively encoding valuable items.