The effect of warnings on false memories in young and older adults

In the present experiments, we examined adult age differences in the ability to suppress false memories, using the Deese-Roediger-McDermott (DRM) paradigm (Deese, 1959; Roediger & McDermott, 1995). Participants studied lists of words (e.g., bed, rest, awake, etc.), each related to a nonpresented critical lure word (e.g., sleep). Typically, recognition tests reveal false alarms to critical lures at rates comparable to those for hits for studied words. In two experiments, separate groups of young and older adults were unwarned about the false memory effect, warned before studying the lists, or warned after study and before test. Lists were presented at either a slow rate (4 sec/word) or a faster rate (2 sec/word). Young adults were better able to discriminate between studied words and critical lures when warned about the DRM effect either before study or after study but before retrieval, and their performance improved with a slower presentation rate. Older adults were able to discriminate between studied words and critical lures when given warnings before study, but not when given warnings after study but before retrieval. Performance on a working memory capacity measure predicted false recognition following study and retrieval warnings. The results suggest that effective use of warnings to reduce false memories is contingent on the quality and type of encoded information, as well as on whether that information is accessed at retrieval. Furthermore, discriminating between similar sources of activation is dependent on working memory capacity, which declines with advancing age.     

Effective warnings in the Deese-Roediger-McDermott false-memory paradigm: the role of identifiability

These experiments document that warnings can substantially reduce false memories in the Deese-Roediger-McDermott (DRM) paradigm when the critical items are easily identifiable. Participants in a norming study identified the critical item after hearing a list of words. The lists with critical items that could be identified by the largest proportion of participants (high identifiable [HI] lists) and the smallest proportion of participants (low identifiable [LI] lists) were used in the experiment. Participants heard lists of words (e.g., bed, rest, doze) related to a critical item (e.g., sleep) and were warned about the nature of the lists before the study phase. The results indicated that warnings reduced false recognition of critical items for HI lists but not LI lists.     

错误记忆的自我参照效应：易化的作用

采用DRM范式,设置三种参照对象条件（自我、他人和中性参照）,考察错误记忆是否存在自我参照效应。结果发现：（1）与正确记忆一样,错误记忆中亦存在自我参照效应;（2）无论是正确记忆还是错误记忆,自我参照条件下的回忆成分均显著多于他人参照和中性参照,但熟悉性成分在三种不同参照对象条件下没有显著差异;（3）当词表中学习项目由分组呈现变为随机呈现时,错误记忆的自我参照效应仍稳定存在。结果揭示,自我参照效在促进正确记忆的同时,亦可易化错误记忆效应。     

Making it last: Combating hedonic adaptation in romantic relationships

Increasing evidence that positive affect enhances associative processing has lent weight to the idea that positive affect increases false memory for information that is thematically interrelated. Using the Deese–Roediger–McDermott paradigm, we examined whether mild positive affect facilitates monitoring processes in modulating false memory for associate words. When participants in the warned condition – in contrast to those in the unwarned condition – were overtly warned about possible false recognition of the critical lure, we found that positive affect, compared to neutral affect, significantly enhanced monitoring through a warning and reduced false recognition. Signal detection analyses suggest that when a warning is provided, positive affect enhances sensitivity to discriminate list items from critical lures, but it does not shift the overall decision criterion. Taken together, we conclude that positive affect facilitates the effect of a warning in reducing false memories for semantic associates.     

False memory in a short-term memory task

The Deese/Roediger-McDermott (DRM; Roediger & McDermott, 1995) paradigm reliably elicits false memories for critical nonpresented words in recognition tasks. The present studies used a Sternberg (1966) task with DRM lists to determine whether false memories occur in short-term memory tasks and to assess the contribution of latency data in the measurement of false memories. Subjects studied three, five, or seven items from DRM lists and responded to a single probe (studied or nonstudied). In both experiments, critical lures were falsely recognized more often than nonpresented weak associates. Latency data indicated that correct rejections of critical lures were slower than correct rejections of weakly related items at all set sizes. False alarms to critical lures were slower than hits to list items. Latency data can distinguish veridical and false memories in a short-term memory task. Results are discussed in terms of activation-monitoring models of false memory.     

The role of test structure in creating false memories

In the Deese/Roediger-McDermott (DRM) paradigm, studying lists of semantic associates results in high rates of false recognition of a nonpresented critical word. The present set of experiments was designed to measure the contribution of additional processing of list items at test to this false memory effect. The participants studied sets of lists and then performed a recognition task for each set. In three experiments, using this paradigm, we investigated false recognition when the number of studied list items presented at test (0, 6, or 12) was manipulated. In Experiments 2 and 3, false recognition of critical lures associated to both studied and nonstudied lists increased significantly as the number of list items included in the test increased. These results indicate that processes occurring at retrieval contribute to false memory effects found with the DRM paradigm.     

Test-induced priming of false memories

Of interest was whether prior testing of related words primes false memories in the Deese/Roediger-McDermott (DRM) paradigm. After studying lists of related words, subjects made old-new judgments about zero, three, or six related items before being tested on critical nonpresented lures. When the recognition test was self-paced, prior testing of list items led to faster false recognition judgments, but did not increase the rate of false alarms to lures from studied lists. Critically, this pattern changed when decision making at test was speeded. When forced to respond quickly—presumably precluding the use of monitoring processes—clear test-induced priming effects were observed in the rate of false memories. The results are consistent with an activation-monitoring explanation of false memories and support that retrieving veridical memories can be a source of memory error.     

Do instructional warnings reduce false recognition?

After previously encoding lists of related words (e.g. bed, rest, awake, etc.) associated with one critical word (e.g. sleep), participants frequently falsely recognize critical words as having been previously presented. Past research indicates that warning participants of this memory illusion can reduce false recognition of critical words. However, the memory processes responsible for this reduction are not known. We investigated whether the increase in critical‐word memory performance reflects changes that are specific to the processing of critical words, or alternatively, changes that are applied generally to processing in all conditions. Different participants were warned (in two different ways) or not warned before encoding, and recognition sensitivity for critical words, related words and unrelated words was tested. The warnings increased memory performance equally across all conditions, not just for critical words. These results help to more effectively conceptualize false recognition and reductions in false recognition in this paradigm. Copyright © 2005 John Wiley & Sons, Ltd.     

Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

The effect of mood on false memory for emotional DRM word lists

In the present study, we investigated the effect of participants’ mood on true and false memories of emotional word lists in the Deese–Roediger–McDermott (DRM) paradigm. In Experiment 1, we constructed DRM word lists in which all the studied words and corresponding critical lures reflected a specified emotional valence. In Experiment 2, we used these lists to assess mood-congruent true and false memory. Participants were randomly assigned to one of three induced-mood conditions (positive, negative, or neutral) and were presented with word lists comprised of positive, negative, or neutral words. For both true and false memory, there was a mood-congruent effect in the negative mood condition; this effect was due to a decrease in true and false recognition of the positive and neutral words. These findings are consistent with both spreading-activation and fuzzy-trace theories of DRM performance and have practical implications for our understanding of the effect of mood on memory.     

Does test-induced priming play a role in the creation of false memories?

We investigated the role of test-induced priming in creating false memories in the Deese/Roediger-McDermott (DRM) paradigm, in which subjects study lists of related words (bed, rest, awake) and then falsely recall or recognise a related word (sleep) on a later test. However, in experiments using three different procedures, we found that the number of related words tested prior to the critical word had surprisingly little impact on false recall and recognition. We manipulated the location of the critical item in tests of yes/no recognition, word-stem cued recall, and part-set cued recall. We consistently obtained high probabilities of false recall and recognition, but the probability was unaffected by the number of related items presented prior to the test of the critical item. Surprisingly, test-induced priming of the critical item does not seem to play a large role in this memory illusion.     

汉字字形关联对错误记忆的影响

采用DRM范式,研究汉字字形关联对错误记忆的影响。实验以占汉字主体的形声字为材料。学习阶段使用了两类字表:在一半字表中,各字表内汉字及相应的关键诱饵具有相同形旁;另一半字表中,各字表内汉字及相应关键诱饵具有相同声旁。再认测试中,被试对两类关键诱饵均表现出了明显的错误记忆,并且其效应大小与字表汉字相似度成正比。这些结果说明,汉字的字形关联可以诱发错误记忆现象,并且这种错误记忆效应由汉字间字形相似度决定。     

Thinking of critical words during study is unnecessary for false memory in the Deese,Roediger, and McDermott procedure

Do participants in the Deese, Roediger, and McDermott (DRM) procedure demonstrate false memory because they think of nonpresented critical words during study and confuse them with words that were actually presented? In two experiments, 160 participants studied eight visually presented DRM lists at a rate of 2 s or 5 s per word. Half of the participants rehearsed silently: the other half rehearsed overtly. Following study, the participants' memory for the lists was tested by recall or recognition. Typical false memory results were obtained for both memory measures. More important, two new results were observed. First, a large majority of the overt-rehearsal participants spontaneously rehearsed approximately half of the critical words during study. Second, critical-word rehearsal at study enhanced subsequent false recall, but it had no effect on false recognition or remember judgments for falsely recognized critical words. Thinking of critical words during study was unnecessary for producing false memory.     

Assessing the effectiveness of warnings and the phenomenological characteristics of false memories

The phenomenology of false memories was investigated in three experiments in which participants heard two experimenters read lists of items that were related to critical nonpresented items. In Experiments 1, following a recognition memory test, participants rated the phenomenological characteristics of their memories immediately and after a 48-hour delay. False recognition was prevalent and on several dimensions participants rated their true memories as more vivid than their false memories. In Experiments 2 and 3, following the study phase, participants were warned about the phenomenological differences between true and false memories and were instructed to use this information to avoid reporting nonpresented items. This type of warning was ineffective at reducing false recall (Experiment 2) and false recognition (Experiment 3) relative to unwarned participants. Importantly, the inability of explicit warnings to impact illusory recollections demonstrates that the false memories cannot be attributed simply to a criterion shift.     

Assessing the effectiveness of warnings and the phenomenological characteristics of false memories

The phenomenology of false memories was investigated in three experiments in which participants heard two experimenters read lists of items that were related to critical nonpresented items. In Experiments 1, following a recognition memory test, participants rated the phenomenological characteristics of their memories immediately and after a 48-hour delay. False recognition was prevalent and on several dimensions participants rated their true memories as more vivid than their false memories. In Experiments 2 and 3, following the study phase, participants were warned about the phenomenological differences between true and false memories and were instructed to use this information to avoid reporting nonpresented items. This type of warning was ineffective at reducing false recall (Experiment 2) and false recognition (Experiment 3) relative to unwarned participants. Importantly, the inability of explicit warnings to impact illusory recollections demonstrates that the false memories cannot be attributed simply to a criterion shift.     

强大的错误记忆效应:词表呈现时间与呈现方式的影响

本研究采用DRM范式(Deese-Roediger-McDermott paradigm),考察了词表项目的呈现时间与呈现方式对错误记忆效应的影响。结果发现,被试对关键诱饵的错误再认受到学习阶段词表项目的呈现方式的影响,表现为所有项目随机呈现条件下的错误再认明显低于分组呈现条件,尤其是在20ms的随机呈现条件下,观察到了对关键诱饵的最低错误再认率。说明在对词表项目的编码阶段产生了对关键诱饵的连续激活,而对关键诱饵的错误记忆则是基于连续激活的不断累积的结果,当词表项目的随机呈现阻断了连续激活过程时,便会有效降低错误记忆效应。而且,在所有实验条件下均发现了错误记忆效应产生中所伴随的强烈主观体验,证实了错误记忆是一种强大的效应。     

The role of rehearsal and generation in false memory creation

The current research investigated one possible mechanism underlying false memories in the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, participants who study lists of related words (e.g., "table, sitting, bench ...") frequently report detailed memories for the centrally related but non-presented critical lure (e.g., "chair"). One possibility is that participants covertly call to mind the critical non-presented lure during the study phase, and later misattribute memory for this internally generated event to its external presentation. To investigate this, the DRM paradigm was modified to allow collection of on-line thoughts during the study phase. False recognition increased following generation during study. False recognition also increased following study of longer lists; this effect was partially explained by the fact that longer lists were more likely to elicit generations of the critical lure during study. Generation of the lure during study contributes to later false recognition, although it does not explain the entire effect.     

False memory across languages: implicit associative response vs fuzzy trace views

We investigated false recognition across languages using the Deese-Roediger-McDermott (DRM) paradigm. A group of English-French bilinguals studied lists of converging associates, some lists in English and some in French, and then performed a recognition test containing studied list items and nonstudied critical lures whose language matched or mismatched the language at study. Participants were instructed to answer old only if the test cue was in the same language as the studied word. The results yielded a robust false memory rate both within-language and across-languages. The effect of the study-test language shift was much larger for list items than for critical lures. This finding suggests that memory representations for critical lures contain primarily semantic gist traces and little surface information, and hence is more consistent with the fuzzy trace view than with the implicit associative response view. In sum, the study demonstrates the existence of false memory across languages, and provides information about the memory traces underlying veridical and illusory recognition.     

The role of rehearsal and generation in false memory creation

The current research investigated one possible mechanism underlying false memories in the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, participants who study lists of related words (e.g., “table, sitting, bench …”) frequently report detailed memories for the centrally related but non-presented critical lure (e.g., “chair”). One possibility is that participants covertly call to mind the critical non-presented lure during the study phase, and later misattribute memory for this internally generated event to its external presentation. To investigate this, the DRM paradigm was modified to allow collection of on-line thoughts during the study phase. False recognition increased following generation during study. False recognition also increased following study of longer lists; this effect was partially explained by the fact that longer lists were more likely to elicit generations of the critical lure during study. Generation of the lure during study contributes to later false recognition, although it does not explain the entire effect.