How similar is false recognition to veridical recognition objectively and subjectively?

Three recognition memory experiments were conducted using modified Deese-Roediger-McDermott (DRM) and DRM paradigms. In Experiment 1, the reaction time (RT) of the false alarms to critical nonpresented words (false memory) was compared with the RT of hits to the critical presented words and with the RT of hits to the studied list words (true memory). The RT of the false alarms to the critical nonpresented words was significantly longer than that of the hits to the critical words and than that of the studied list words. In Experiment 2, in addition to RT, participants' confidence level was measured on a 4-point scale for a yes or no response. Confidence rating was significantly higher for the hits to the critical presented words and to the list words than for the false alarms to the critical non-presented words. Experiment 3 further showed that how similar false memory experience was to that of true memory was a function of retention size (number of lists of words retained in memory). In all three experiments, the participants' recognition RTs distinguished false memory from veridical memory, and in Experiments 2 and 3, so did their confidence ratings. Therefore, false memory and veridical memory differ at both the objective and the subjective levels. The results are consistent with a single familiarity dimension model of recognition memory.     

The effects of mediated word lists on false recall and recognition

False memory effects were explored using unrelated list items (e.g., slope, reindeer, corn) that were related to mediators (e.g., ski, sleigh, flake) that all converged upon a single nonpresented critical item (CI; e.g., snow). In Experiment 1, participants completed either an initial recall test or arithmetic problems after study, followed by a final recognition test. Participants did not falsely recall CIs on the initial test; however, false alarms to CIs did occur in recognition, but only following an initial recall test. In Experiment 2, participants were instructed to guess the CI, followed by a recognition test. The results replicated Experiment 1, with an increase in CI false alarms. Experiment 3 controlled for item effects by replacing unrelated recognition items from Experiment 1 with both CIs and list items from nonpresented lists. Once again, CI false alarms were found when controlling for lexical characteristics, demonstrating that mediated false memory is not due simply to item differences.     

Part-set cuing of false memories

Part-set cuing inhibition describes the common finding that re-presenting items from a word list can reduce subjects’ overall recall performance for studied items. Do part-set cuing effects occur for false memories as well? In the present experiments, subjects studied lists of words drawn from Roediger and McDermott (1995). After studying each list, subjects completed math problems and then recalled the list items either with or without accompanying list cues. In Experiment 1, the recall cues consisted of items drawn randomly from the original list. In Experiment 2, an additional type of cued recall task was added in which the even numbered list items were used as cues. Taken together, these experiments demonstrate robust part-set cuing effects for critical nonpresented items. In addition, they show that whereas recall of critical words is reduced by the presence of cues at test, retrieval cues do not affect critical words and studied words in exactly the same manner.     

False recognition and word length: A reanalysis of Roediger,Watson, McDermott,and Gallo (2001) and some new data

Roediger, Watson, McDermott, and Gallo (2001) reported a multiple regression analysis of the variables that predicted rates of false recall and recognition across lists in the Deese/Roediger— McDermott paradigm. They concluded that false recollection was predictable from the backward associative strength of critical words and list words and the veridical recall level of list words, with no independent contribution of frequency, concreteness, or length of critical words. A reanalysis of their data shows that critical word length does contribute to false recognition when it is measured relative to the length of other words in the list. Relative word length in the form of an unsignedz-score has a larger correlation with false recognition than any of the variables used by Roediger et al. and is also independently predictive of false recognition. This relationship was confirmed by the results of two recognition experiments in which false positives were significantly less frequent for words of lengths that never occurred in a studied list than for words of lengths that did occur in the study list.     

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.     

Memory distortion in group recall

Earlier we reported (Basden, Basden, Bryner, ...Thomas, 1997) that, in comparison with nominal groups (three people tested individually), three-person collaborative groups recalled fewer presented words but intruded more nonpresented words. In the present research, Experiment 1 showed that when presented words were associatively related to critical nonpresented words, collaboration inhibited recall of presented words but did not influence recall of critical nonpresented words. Experiment 2 showed that with categorized lists, recall of high taxonomic frequency critical nonpresented words was greater for collaborative groups than for nominal groups. Collaboration did not inhibit recall of presented words, presumably because guessing supplemented recall in collaborative groups. Greater false recall in collaborative than in nominal groups appears to result from activation of superordinate-to-item associations rather than item-to-item associations.     

False recognition of associates: How robust is the effect?

False recognition of nonpresented words that were strong associates of 12 words in a study list was examined. Six lists were read to subjects; each list contained the 12 strongest associates to a critical nonpresented word. False-alarm rates to the 6 critical nonpresented words were obtained under several different conditions. The manipulations included varying the level of processing done to the study lists, varying the recognition-test procedure, repeating each of the study lists three times, and mixing the words from the six study lists together. A reliable false-recognition effect for critical nonpresented words was obtained in all conditions. However, the effect was not impervious to all of the manipulations. Significantly lower false recognition was obtained when learning was incidental as well as when the words on the six lists were mixed together. Neither level of processing nor repetition significantly influenced false recognition. This last result is inconsistent with Hintzman’s (1988) MINERVA 2 global memory model, but agrees with predictions from Shiffrin, Ratcliff, and Clark’s (1990) SAM model.     

Retrieval conditions and false recognition: testing the distinctiveness heuristic

High levels of false recognition are observed after people study lists of semantic associates that all converge on a nonpresented lure word. In previous experiments, we have found that orienting participants to encode distinctive information about study list items by presenting them as pictures as opposed to words produces marked reductions in false recognition. We have suggested that these reductions reflect the operation of a distinctiveness heuristic: Participants demand access to detailed pictorial information in order to support a positive recognition decision. The present experiments provide additional evidence on this point and allow us to distinguish between the distinctiveness heuristic account and an alternative account based on the impoverished encoding of relational information that occurs when one is studying pictures. In Experiment 1, even when only half of the items in a study list were presented as pictures, a general suppression of false recognition was observed that could be attributable to impoverished encoding of relational information. Experiment 2 provided a critical test of the distinctiveness heuristic account: We manipulated test instructions and found that differences in false recognition rates between picture and word encoding were attenuated in a retrieval condition that did not encourage reliance on a distinctiveness heuristic.     

Category structure and created memories

Cued recall of categorized lists was used to examine effects of category structure on the creation of false memories. In three experiments, category members that had not been presented on studied categorized lists were nonetheless recalled by participants. Delaying the category cued recall test (Experiment 1) and priming category members that had been omitted from target lists (Experiment 3) increased the frequency of false recall. All three experiments showed that nonpresented category members that were higher in output dominance were more frequent intrusions. The typicality of category members, however, did not uniquely contribute to the predictability of false recall (or accurate recall) once the contribution of output dominance was taken into account, suggesting that item accessibility (related to output dominance) may be more instrumental than item distinctiveness (related to typicality) in causing certain types of false recall. The results show that created memories in category cued recall are strongly biased by prior category knowledge and can be predicted by the graded structure of categories, particularly in terms of the output dominance of category instances.     

False recognition in younger and older adults: Exploring the characteristics of illusory memories

Roediger and McDermott (1995) demonstrated that when subjects hear a list of associates to a “theme word” that has itself not been presented, they frequently claim to recollect having heard the nonpresented theme word on the study list. In Experiment 1, we found that asking subjects to explain theirremember responses, by writing down exactly what they remembered about the item’s presentation at study, did not significantly diminish the rate ofremember false alarms to nonpresented theme words. We also found that older adults were relatively more susceptible than younger adults to this false-recognition effect. Subjects’ explanations suggested that both veridical and illusory memories were predominantly composed of associative information as opposed to sensory and contextual detail. In Experiment 2, we obtained quantitative evidence for this conclusion, using a paradigm in which subjects were asked focused questions about the contents of their recollective experience. Lastly, we found that both younger and older adults recalled more sensory and contextual detail in conjunction with studied items than with nonpresented theme words, although these differences were less pronounced in older adults.     

The difference between implicit and explicit associative processes at study in creating false memory in the DRM paradigm

The effects of implicit and explicit associative processes for false recognition were examined by manipulating exposure duration of studied items; 20 ms or 2000 ms. Participants studied lists of words that were high associates to a nonpresented word (critical lure) in either condition. After learning each list, they took a recognition test and remember/know judgements immediately (Experiment 1) or 1 minute later (Experiment 2). In Experiment 1, know responses for critical lures were more in the 20 ms than in the 2000 ms conditions, while remember responses for them were more in the 2000 ms condition. Implicit associative processes create familiarity of critical lures, and explicit associative processes create details of false memories. Comparing the results of Experiment 1 with those of Experiment 2, remember responses for critical lures were increased with the prolonged time only in the 20 ms condition. Characteristics of false memory made by implicit associative processes could be changed by prolonged time.     

The difference between implicit and explicit associative processes at study in creating false memory in the DRM paradigm

The effects of implicit and explicit associative processes for false recognition were examined by manipulating exposure duration of studied items; 20 ms or 2000 ms. Participants studied lists of words that were high associates to a nonpresented word (critical lure) in either condition. After learning each list, they took a recognition test and remember/know judgements immediately (Experiment 1) or 1 minute later (Experiment 2). In Experiment 1, know responses for critical lures were more in the 20 ms than in the 2000 ms conditions, while remember responses for them were more in the 2000 ms condition. Implicit associative processes create familiarity of critical lures, and explicit associative processes create details of false memories. Comparing the results of Experiment 1 with those of Experiment 2, remember responses for critical lures were increased with the prolonged time only in the 20 ms condition. Characteristics of false memory made by implicit associative processes could be changed by prolonged time.     

Recall accuracy and illusory memories: when more is less

In two experiments it was revealed that manipulations that increased recall of studied list items also increased false recall of theme-related, critical nonpresented words. In Experiment 1 subjects listened to a series of short word lists, each containing items associatively related to a theme, while engaging in either semantic or nonsemantic processing. On an immediate free recall test semantic processors demonstrated greater correct recall as well as more illusory memories of critical nonpresented items than nonsemantic processors. In Experiment 2, the short study lists were combined to form longer lists that were presented either blocked by theme or in a random presentation order. Retention interval was also varied as participants were tested either immediately, one week after, or three weeks after the study phase. Presenting the target items in a blocked, as opposed to random, format increased recall accuracy, but this was at the expense of a higher intrusion rate for theme-consistent items. Interestingly, the level of false memories was not affected by retention interval even though typical decrements in the recall of study items were observed over time. The results of these experiments highlight the persistence of the false memory effect, as well as pointing to several factors, primarily semantic processing, that may lead to the creation of false memories. Interpretations are offered within the theoretical frameworks of source monitoring and fuzzy trace theory.     

False memory for associated word lists in individuals and collaborating groups

Using the Deese/Roediger-McDermott (DRM) paradigm, we investigated recall of presented and nonpresented associated words by collaborating groups, nominal groups, and individuals. In Experiment 1, participants recalled individually and then recalled in collaborating groups. Nominal groups made up of individual recall produced more presented and nonpresented associated words than did collaborating groups. Collaborating groups recalled more presented words than did individuals, but not more nonpresented words. In Experiment 2, collaborating groups versus individuals was a between-subjects variable, and everyone made two recall attempts. For recall, the pattern was the same as that in Experiment 1, in that collaborating groups recalled more presented words than did individuals but about the same number of nonpresented words. In a DRM paradigm, collaborating groups were able to produce more presented words than were individuals, without increasing their false recall.     

The effects of emotional content and aging on false memories

After studying a list of words related to a nonpresented lure word, people often falsely recall or recognize the nonpresented lure. Older adults are particularly susceptible to these forms of false memories. The age-related false memory enhancement likely occurs because older adults do not encode, or later retrieve, items in enough detail to allow them to discriminate between presented words and other associated but nonpresented items. Pesta, Murphy, and Sanders (2001) suggested that the emotional salience of the lures may provide distinctiveness, so that individuals would be less likely to endorse an emotional lure as a studied item than to endorse a neutral lure. In the present investigation, young and older adults were less likely to falsely recall or recognize emotional, as compared with neutral, lures. Both age groups appeared capable of using the distinctiveness of the emotional lures to reduce, although not to eliminate, false recall and recognition.     

项目特异性加工和关系加工对非熟练中-英双语者跨语言错误记忆的影响

采用DRM范式进行跨语言错误记忆的研究较为鲜见, 而且得出了许多不同的结果, 关于错误记忆跨语言产生的理论解释也是各执己见。研究以非熟练中-英双语大学生为被试, 采用DRM范式对非熟练中-英双语者的跨语言错误记忆进行了研究。在2个实验中, 分别探讨了项目特异性加工和关系加工条件下, 语义激活的不同水平对跨语言错误记忆的影响。结果发现：1)非熟练中-英双语者也存在跨语言的错误记忆; 2)在项目特异性加工和关系加工条件下, 相同语言内与不同语言间发生关键诱词的错误再认的结果是不同的; 3)只在项目特异性加工条件下, 长词表比短词表会诱发更多的对关键诱词的错误再认。研究结果支持了激活-监测理论。     

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.     

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.     

Transmitting false memories in social groups

In 2 experiments, subjects studied word lists drawn from Roediger and McDermott (1995) and then participated in perceived group recall (PGR) tests that were intended to lead each subject to believe that she or he was participating in collaborative recall in a 4-person group. Some of the lists were followed by PGR tests containing the nonpresented critical word, some lists were followed by PGR tests not containing the nonpresented critical word, and some lists were not followed by PGR tests. Subjects then completed individually administered recall tests and subsequent immediate or delayed recognition tests that required remember or know judgments. The major finding was that critical words contained within PGR tests were as likely to be falsely recalled, recognized, and consciously remembered as original list items. These findings show that false memories can be socially transmitted.     

Pictorial encoding reduces false recognition of semantic associates

High levels of false recognition can be observed after people study lists of semantic associates that all converge on a nonpresented lure word. To test the idea that encoding distinctive perceptual information would help to reduce false recognition, we presented a line drawing representing each associated word during study list presentation and later tested recognition of studied words and lure words. Two experiments revealed marked reductions in false recognition after pictorial encoding, relative after to word encoding. Results suggest that people reject related and unrelated lures because these items lack the distinctive qualities associated with remembered pictures.