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.     

Why distinctive information reduces false memories: evidence for both impoverished relational-encoding and distinctiveness heuristic accounts

Two accounts explain why studying pictures reduces false memories within the Deese-Roediger-McDermott paradigm (J. Deese, 1959; H. L. Roediger & K. B. McDermott, 1995). The impoverished relational-encoding account suggests that studying pictures interferes with the encoding of relational information, which is the primary basis for false memories in this paradigm. Alternatively, the distinctiveness heuristic assumes that critical lures are actively withheld by the use of a retrieval strategy. When participants were given inclusion recall instructions to report studied items as well as related items, they still reported critical lures less often after picture encoding than they did after word encoding. As the impoverished relational-encoding account suggests, critical lures appear less likely to come to mind after picture encoding than they do after word encoding. However, the results from a postrecall recognition test provide evidence in favor of the distinctiveness heuristic.     

Autobiographical elaboration reduces memory distortion: cognitive operations and the distinctiveness heuristic

Retrieval monitoring enhances episodic memory accuracy. For instance, false recognition is reduced when participants base their decisions on more distinctive recollections, a retrieval monitoring process called the distinctiveness heuristic. The experiments reported here tested the hypothesis that autobiographical elaboration during study (i.e., generating autobiographical memories in response to cue words) would lead to more distinctive recollections than other item-specific encoding tasks, enhancing retrieval monitoring accuracy at test. Consistent with this hypothesis, false recognition was less likely when participants had to search their memory for previous autobiographical elaborations, compared to previous semantic judgments. These false recognition effects were dissociated from true recognition effects across four experiments, implicating a recollection-based monitoring process that was independent from familiarity-based processes. Separately obtained subjective measures provided converging evidence for this conclusion. The cognitive operations engaged during autobiographical elaboration can lead to distinctive recollections, making them less prone to memory distortion than other types of deep or semantic encoding.     

Both differences in encoding processes and monitoring at retrieval reduce false alarms when distinctive information is studied

A reduction in false alarms to critical lures is observed in the DRM paradigm (Roediger & McDermott, 1995) when distinctive information is presented at encoding. Two mechanisms have been proposed to account for this reduction. According to the monitoring theory (e.g., the distinctiveness heuristic), lack of diagnostic recollection serves as a basis for discarding non-presented lures. According to the encoding theory, presenting distinctive information at study leads to impoverished relational processing, which results in a reduction in memorial information elicited by critical lures. In the present study a condition was created in which the use of the distinctiveness heuristic was precluded by associating, within the same study, lures with distinctive information in a context different from the study session. Under that condition reduction in false alarms to distinctive critical lures was still observed. This result supports the predictions of the encoding theory. However, when in the same study the use of the distinctiveness heuristic was not precluded, reductions in false alarms to unrelated lures were also observed when distinctive information was presented at study, indicating that both mechanisms are likely to contribute to the rejection of false memories.     

Distinctive encoding reduces the Jacoby—Whitehouse illusion

We investigated the influence of distinctive encoding on the Jacoby and Whitehouse (1989) illusion. Subjects studied visually presented words that were associated with either an auditory presentation of the same word (nondistinctive encoding) or a picture of the object (distinctive encoding). In both conditions, words were visually presented on the recognition test, and half were preceded by brief repetition primes. Priming test items increased hits and false alarms in the auditory condition, demonstrating the Jacoby-Whitehouse illusion. This illusion was reduced in the picture condition. In order to test whether this distinctiveness effect was caused by a recollection-based response strategy (i.e., the distinctiveness heuristic), we minimized recollection-based responding by having subjects make speeded recognition decisions. Contrary to the distinctiveness heuristic hypothesis, speeded responding did not eliminate the distinctiveness effect on the Jacoby-Whitehouse illusion. Picture encoding may reduce this illusion via a shift in preretrieval orientation, as opposed to a postretrieval editing process.     

Getting at the source of distinctive encoding effects in the DRM paradigm: evidence from signal-detection measures and source judgments

Studying Deese–Roediger–McDermott (DRM) lists using a distinctive encoding task can reduce the DRM false memory illusion. Reductions for both distinctively encoded lists and non-distinctively encoded lists in a within-group design have been ascribed to use of a distinctiveness heuristic by which participants monitor their memories at test for distinctive-task details. Alternatively, participants might simply set a more conservative response criterion, which would be exceeded by distinctive list items more often than all other test items, including the critical non-studied items. To evaluate these alternatives, we compared a within-group who studied 5 lists by reading, 5 by anagram generation, and 5 by imagery, relative to a control group who studied all 15 lists by reading. Generation and imagery improved recognition accuracy by impairing relational encoding, but the within group did not show greater memory monitoring at test relative to the read control group. Critically, the within group’s pattern of list-based source judgments provided new evidence that participants successfully monitored for distinctive-task details at test. Thus, source judgments revealed evidence of qualitative, recollection-based monitoring in the within group, to which our quantitative signal-detection measure of monitoring was blind.     

Generation and mnemonic encoding induce a mirror effect in the DRM paradigm

Encoding tasks that increase memory accuracy are appealing from both practical and theoretical perspectives. Within the Deese/Roediger-McDermott (DRM) paradigm, we found that generating list words from anagrams (relative to reading) produced a mirror effect: enhanced recognition of studied words coupled with a reduction in false recognition. Signal detection analyses suggest that the increase in correct recognition was due to enhanced item-specific encoding of the list words, whereas the reduction in false recognition was due to enhanced strategic monitoring at test (i.e., a distinctiveness heuristic), rather than to reduced relational encoding at study. Further support for a distinctiveness heuristic account was obtained using both "theme judgment" instructions and within-group conditions. In our final experiment, we replicated this mirror effect using a purely mnemonic (self-referential) encoding task, showing that extra perceptual cues are not necessary to induce participants to adopt a successful memory-improvement strategy at test.     

"If I had said it I would have remembered it": reducing false memories with a distinctiveness heuristic

We examined the contributions of decision processes to the rejection of false memories. In two experiments, people studied lists of semantically related words and then completed a recognition test containing studied words, unrelated lure words, and related lure words. People who said words aloud at study were less likely to falsely recognize related lures on the test than were those who heard words at study. We suggest that people who said words at study employed a distinctiveness heuristic during the test whereby they demanded access to distinctive say information in order to judge an item as old. Even when retrieving say information is not perfectly diagnostic of prior study, as in Experiment 2, in which participants both said and heard words at study, people persist in using the distinctiveness heuristic to reduce false memories.     

Reduced effects of pictorial distinctiveness on false memory following dynamic visual noise

High levels of false recognition for non-presented items typically occur following exposure to lists of associated words. These false recognition effects can be reduced by making the studied items more distinctive by the presentation of pictures during encoding. One explanation of this is that during recognition, participants expect or attempt to retrieve distinctive pictorial information in order to evaluate the study status of the test item. If this involves the retrieval and use of visual imagery, then interfering with imagery processing should reduce the effectiveness of pictorial information in false memory reduction. In the current experiment, visual-imagery processing was disrupted at retrieval by the use of dynamic visual noise (DVN). It was found that effects of DVN dissociated true from false memory. Memory for studied words was not influenced by the presence of an interfering noise field. However, false memory was increased and the effects of picture-induced distinctiveness was eliminated. DVN also increased false recollection and remember responses to unstudied items.     

Encoding and retrieval processes in the memory for conceptually distinctive events

Memory for conceptually isolated (distinctive) words was investigated in two experiments. In Experiment 1, recognition of distinctive targets was compared with recognition of targets from homogeneous lists and with recognition of background information. Distinctive targets were better recognized than the same words presented in homogeneous lists. No effects of distinctiveness on the recognition accuracy of background items were observed. These results fail to support the hypothesis that distinctive information receives extra resources during encoding at the expense of surrounding background information. In Experiment 2 the effects of distinctiveness on recall were evaluated. Distinctive targets were more likely to be recalled than targets from homogeneous lists. However, unlike the effects found in recognition, background items were more poorly recalled from lists containing distinctive targets than from homogeneous lists. Organizational processes in recall were also evaluated. There was greater subjective organization for target and background items from lists containing distinctive targets than from lists containing nondistinctive targets. These results were discussed in terms of encoding and retrieval explanations of the effects of distinctiveness.     

Aging and strategic retrieval processes: reducing false memories with a distinctiveness heuristic

The authors show that a strategic retrieval process--the distinctiveness heuristic--is a powerful mechanism for reducing false memories in the elderly. Individuals studied words, pictures, or both types of items and then completed a recognition test on which the studied items appeared once, whereas the new words appeared twice. After studying either pictures only or a mixture of pictures and words, both younger and older adults falsely recognized fewer repeated new words than did participants who studied words. Studying pictures provided a basis for using a distinctiveness heuristic during the recognition test: Individuals inferred that the absence of memory for picture information indicates that an item is "new."     

Encoding distinctiveness and the encoding shift penalty in children and adults

This study determined some of the reasons for developmental differences in retrieval variability. The critical manipulation involved the use of semantic orienting questions at both acquisition and retrieval for elementary school children (7 and 10 years of age) and adults. The retrieval questions biased the sampling of cue information compatible or incompatible with the information sampled in acquisition. The recall difference that resulted is the Encoding Shift Penalty. Experiment 1 manipulated encoding distinctiveness at acquisition and the delay between acquisition and retrieval. Experiment 2 varied acquisition encoding constraint and employed two retrieval trials varying the kind of retrieval question. Among other findings, the results suggest that (1) the acquisition encoding of adults is more distinctive than is that of children; (2) encoding distinctiveness affects the probability of sampling and resampling compatible cue information, and the identification of target event information once cue comptibility is ensured at retrieval; and (3) incompatible initial samples of retrieval cue information for children may interfere with their ability to resample successfully.     

Two types of recollection-based monitoring in younger and older adults: Recall-to-reject and the distinctiveness heuristic

People often use recollection to avoid false memories. At least two types of recollection-based monitoring processes can be identified in the literature. Recall-to-reject is based on the recall of logically inconsistent information (which disqualifies the false event from having occurred), whereas the distinctiveness heuristic is based on the failure to recall to-be-expected information (which is diagnostic of non-occurrence). We attempted to investigate these hypothetical monitoring processes in a single task, as a first step at delineating the functional relationship between them. By design, participants could reject familiar lures by (1) recalling them from a to-be-excluded list (recall-to-reject) or (2) realising the absence of expected picture recollections (the distinctiveness heuristic). Both manipulations reduced false recognition in young adults, suggesting that these two types of monitoring were deployed on the same test. In contrast, older adults had limited success in reducing false recognition with either manipulation, indicating deficits in recollection-based monitoring processes. Depending on how a retrieval task is structured, attempts to use one monitoring process might interfere with another, especially in older adults.     

Metamemorial influences in recognition memory: Pictorial encoding reduces conjunction errors

Two experiments are presented that explore the role of the distinctiveness heuristic (e.g., Schacter, Israel, & Racine, 1999) on rates of conjunction errors as a function of encoding condition. The results of Experiment 1 demonstrate a reliable reduction of conjunction errors when participants study pictures relative to both reading words aloud and silently. Experiment 2 demonstrates that the nature of the pictures presented during the study phase is important for reducing conjunction errors. Collectively, the experiments demonstrate that participants can use the distinctiveness heuristic in addition to recall-to-reject strategies to avoid conjunction errors. These findings add to a growing body of literature that suggests that participants are able to use expectations for memory to guide their recognition decisions.     

Item-specific processing reduces false memories

We examined the effect of item-specific and relational encoding instructions on false recognition in two experiments in which the DRM paradigm was used (Deese, 1959; Roediger & McDermott, 1995). Type of encoding (item-specific or relational) was manipulated between subjects in Experiment 1 and within subjects in Experiment 2. Decision-based explanations (e.g., the distinctiveness heuristic) predict reductions in false recognition in between-subjects designs, but not in within-subjects designs, because they are conceptualized as global shifts in decision criteria. Memory-based explanations predict reductions in false recognition in both designs, resulting from enhanced recollection of item-specific details. False recognition was reduced following item-specific encoding instructions in both experiments, favoring a memory-based explanation. These results suggest that providing unique cues for the retrieval of individual studied items results in enhanced discrimination between those studied items and critical lures. Conversely, enhancing the similarity of studied items results in poor discrimination among items within a particular list theme. These results are discussed in terms of the item-specific/ relational framework (Hunt & McDaniel, 1993).     

The effects of encoding distinctiveness on retrieval variability in children and adults

To what extent are developmental differences in encoding distinctiveness responsible for differences in retrieval variability? This study examined this question by comparing the effects of different kinds of encoding distinctiveness on the ability of children and adults to reinstate the input environment at retrieval. The critical manipulations involved the use of semantic orienting questions at both encoding and retrieval. Second and fourth (Experiment 1) or fifth (Experiment 2) graders and college adults were given moderately associated word pairs (Knife-Axe) at input. Encoding was free or constrained at input and retrieval. The retrieval questions biased the Same interpretation of the cue as at input (weapon), a uniquely Different interpretation (utensil), or an inappropriate Negative interpretation. Encoding distinctiveness was varied by crossing these manipulations with either picture or word input (Experiment 1) or general or distinctive orienting questions (Experiment 2). The results suggested that encoding distinctiveness and retrieval variability contribute independently to developmental differences in recall.     

Adapting to test structure: Letting testing teach what to learn

We propose that we encode and store information as a function of the particular ways we have used similar information in the past. More specifically, we contend that the experience of retrieval can serve as a powerful cue to the most effective ways to encode similar information in comparable future learning episodes. To explore these ideas, we did two studies in which all participants went through study–test cycles of single category lists while we manipulated the nature of the recognition tests. The recognition tests either included only same-category lures or only different-category lures. The experience of repeated testing leads participants to avoid conceptual-based strategies but only when conceptual knowledge was poorly diagnostic for recognition (i.e., in the same-category lures condition). In a second study with a similar manipulation, we showed that repeated testing with lures from the same category as study items improved performance in a final recall surprise test compared to conditions in which different-category lures were used. Such a difference is akin to the one obtained when encoding instructions focus on distinctive item features compared to cases in which the focus is on relational processing. We suggest that testing requirements lead to adaptive changes at encoding.     

Are two heuristics better than one? The fluency and distinctiveness heuristics in recognition memory

Four experiments were conducted to test the impact of having multiple heuristics (distinctiveness and fluency) available during a recognition test. Recent work by Gallo, Perlmutter, Moore, and Schacter (Memory & Cognition 36:461–466, 2008) suggested that fluency effects are reduced when the distinctiveness heuristic can be applied to a recognition decision. In Experiment 1, we used a response reversal paradigm (Van Zandt & Maldonado-Molina Journal of Experimental Psychology: Learning, Memory, and Cognition 30:1147–1166, 2004) to demonstrate that participants transitioned from an early response strategy that was largely reliant on fluency to a later strategy in which the influences of fluency and distinctiveness were both observable. Experiments 2a, 2b, and 3 showed no evidence for reduction of the fluency heuristic after picture study when the test required a delayed response (Exp. 2a), confidence ratings (Exp. 2b), or the application of conceptual fluency (Exp. 3). The results are consistent with models of memory that assume that familiarity and recollection influence individual memory decisions Wixted (Psychological Review, 114:152–176, 2007).     

Distinctiveness and the recognition mirror effect: evidence for an item-based criterion placement heuristic

Superior detection and rejection of 1 versus another class of items during recognition is called the mirror effect. Some mirror effects may involve strategic criterion adjustments based on item distinctiveness and its relation to memorability. Three experiments demonstrated mirror effects for known versus unknown scenes and 1 suggested a similar pattern for faces. In opposition to preexperimental familiarity, lures from known and frequently encountered locations were confidently rejected more often than unknown lures. Forgetting and speeding recognition reversed this lure response pattern, suggesting abandonment of strategic adjustment in favor of a single fixed criterion. With sufficient response time and recent encoding, observers demand more evidence for conceptually distinctive items, perhaps because such items typically foster vivid recollection during retrieval.     

Retrieval variability: The inefficient use of retrieval cues by young children

The hypothesis of this study is that the inefficient use of retrieval cues by young children is due to retrieval variability: the variable encoding of semantic information in cue stimuli at input and retrieval and the inability to reinterpret cue information to ensure cue-trace compatibility. The critical manipulations involved the use of semantic orienting questions at both input and retrieval. Second and fourth graders and college adults were given moderately associated word pairs (Knife-Axe). Encoding was constrained or free between groups at both input and retrieval. The retrieval questions biased the Same interpretation of the cue as at input (weapon), a uniquely Different interpretation (utensil), or an inappropriate Negative interpretation. Both cued recall and recognition of the target items was tested. The results showed systematic developmental increases both in the distinctiveness of the semantic encoding of stimulus information, and in the ability to reinterpret cue information to ensure cue-trace compatibility. The second graders encoded more variably than the older subjects, and were less able to shift from an incompatible encoding of cue information.