McDermott Paradigm Research Articles

Investigating the mechanisms fuelling reduced false recall of emotional material

We investigated false memory for emotional word lists using the Deese–Roediger–McDermott paradigm. Participants viewed negative, positive, and neutral lists of semantic associates matched on backward associate strength (BAS) and word frequency and recalled as many words as they could remember after each list was presented. Results from two experiments indicated that while participants did create false memories for emotional word lists, neutral lists resulted in the highest false and true recall rates. Experiment 2 used an inclusion task that required participants to recall any words that came to mind and indicate whether the words had actually been presented. The results suggest that emotional words decrease false memories, in part, by encouraging item-specific processing, which consequently impairs the acquisition of relational information and/or the spread of activation to the critical lure.

Influence of suggestion in the DRM paradigm: What state of consciousness is associated with false memory?

We assessed the effect of suggestion on the Deese–Roediger–McDermott paradigm and associated it with the Remember–Know–Guess paradigm. Undergraduate students were given either lists of semantically related words or texts containing these words. After the recall task, if participants did not produce the critical lure, the experimenter suggested that the word had been present, using either a question (moderate suggestion) or an assertion (strong suggestion); these conditions were compared to a condition without suggestion. Afterwards, participants took a recognition test. The results showed that strong suggestions lead to more false recognitions than other conditions and the state of consciousness associated with false recognitions tends to be a feeling of knowing rather than remembering, regardless of the verbal version (list or text). Therefore moderate suggestions did not lead to more false recognitions compare to no suggestion. We discuss the impact of suggestion on consciousness associated with false memories.

Pictorial encoding effects and memory confusions in the Deese–Roediger–McDermott paradigm: Evidence for the activation of spontaneous imagery

The purpose of the experiments reported in this paper was to examine the possible role of spontaneous imagery and list-specific cues on pictorial encoding effects induced by the Deese-Roediger-McDermott (DRM) task. After viewing pictures and words referring to thematically related materials, by way of a picture/word source-judgement task, participants were asked to remember the way in which these materials were presented. Participants reported “seeing” pictures of items that were presented as words, an effect predicted by the imaginal activation hypothesis in its suggestion that incidental images experienced during encoding will later be mistaken as memories for pictures. Whether participants made the same picture misattributions on related lures (or non-presented related items) depended on the way in which the lures’ respective thematic lists were experienced during encoding (Experiments 1 and 2), pointing to the effects of list-specific cues in picture/word judgements. These findings have intriguing implications for interpretations of picture-encoding effects induced by the DRM task. The findings also speak to the use of DRM false-memory rates when marshalling evidence against the use of imagery in applied settings.

The corrective effects of warning on false memories in the DRM paradigm are limited to full attention conditions

Effects of attention control and forewarning on the activation and monitoring of experimentally induced false memories in the Deese/Roediger–McDermott paradigm were investigated in a young adult sample (N=77). We found that reducing the degree of attention during encoding led to a decrease in veridical recall and an increase in non-presented critical lure intrusions. This effect could not be counteracted by a forewarning instruction. However, these findings did not emerge in a (retrieval supportive) recognition task. It seems that divided attention increases false recall when attention control and forewarning have to compete for limited cognitive resources in a generative free recall as opposed to a retrieval supportive recognition task. Forewarning instructions do not always protect young adults against experimentally induced false memories.

Imagery encoding effects on memory in the DRM paradigm: A test of competing predictions

AbstractIn three experiments the effects of imagery encoding and test format on false memory rates in the Deese–Roediger–McDermott (DRM) paradigm were examined. After generating images of individual items (Experiment 1) or integrated subsets (Experiment 2), all of which were embedded in thematically related lists, participants were surprised by a recognition memory test or one of three kinds of source tests. As predicted by a distinctive encoding hypothesis, generating individual images led to better accuracy on presented items, and better monitoring of critical lures, than generating integrated images (Experiments 1 and 2). However, both kinds of imagery encoding led to fewer endorsements of critical lures compared to a non‐imagery encoding condition (Experiment 3). Imagery encoding effects were also independent of test format. The implications of these findings for the use of DRM‐false memory rates in debates about the use of guided imagery techniques are discussed. Copyright © 2008 John Wiley & Sons, Ltd.

Schizotypy and false memory

Using the Deese–Roediger–McDermott (DRM) paradigm the present study examined the relationship between schizotypy and recognition memory. Participants scoring in the upper and lower quartile ranges for schizotypy (Schizotypal Personality Questionnaire brief version; SPQ-B) and on each of the SPQ-B subscales (cognitive-perceptual, interpersonal and disorganized) were compared on true and false memory performance. Participants scoring in the lower quartile range on the cognitive-perceptual subscale recognised a higher proportion of both true and false memories than those scoring in the higher quartile range. Participants scoring in the upper quartile on the interpersonal factor recognised fewer true items than those in the lower quartile range. No differences were found for overall schizotypy or on the disorganized subscale.

Age-related Differences in Brain Activity during True and False Memory Retrieval

Compared to young adults, older adults show not only a reduction in true memories but also an increase in false memories. We investigated the neural bases of these age effects using functional magnetic resonance imaging and a false memory task that resembles the Deese-Roediger-McDermott (DRM) paradigm. Young and older participants were scanned during a word recognition task that included studied words and new words that were strongly associated with studied words (critical lures). During correct recognition of studied words (true memory), older adults showed weaker activity than young adults in the hippocampus but stronger activity than young adults in the retrosplenial cortex. The hippocampal reduction is consistent with age-related deficits in recollection, whereas the retrosplenial increase suggests compensatory recruitment of alternative recollection-related regions. During incorrect recognition of critical lures (false memory), older adults displayed stronger activity than young adults in the left lateral temporal cortex, a region involved in semantic processing and semantic gist. Taken together, the results suggest that older adults' deficits in true memories reflect a decline in recollection processes mediated by the hippocampus, whereas their increased tendency to have false memories reflects their reliance on semantic gist mediated by the lateral temporal cortex.

Divided attention during retrieval suppresses false recognition in confabulation

The present research tested the hypothesis that false recognition in confabulating patients results, at least in part, from sustained processing of irrelevant information about test items. Thus, we predicted that false recognition would be reduced if cognitive resources available for such a processing are experimentally reduced. Two experiments provided evidence consistent with this proposal. In Experiment 1, confabulating patients exhibited lower false recognition in a divided attention (DA) compared to a full attention (FA) retrieval condition. The opposite trend was observed in non-confabulating patients with comparable memory and executive deficits and normal controls. In Experiment 2, in a Deese–Roediger–McDermott paradigm, confabulating patients exhibited lower false recognition to lures that were unrelated to the studied words in the DA compared to the FA retrieval condition, but unvaried levels of false recognition to critical lures. In contrast, false recognition to both unrelated and critical lures increased in non-confabulating patients and normal controls in the DA compared to the FA condition. These results are consistent with the hypothesis that an excessive processing of task-irrelevant memories at retrieval may contribute to false recognition in confabulating patients.

Recall latencies, confidence, and output positions of true and false memories: Implications for recall and metamemory theories

Recall latency, recall accuracy rate, and recall confidence were examined in free recall as a function of recall output serial position using a modified Deese–Roediger–McDermott paradigm to test a strength-based theory against the dual-retrieval process theory of recall output sequence. The strength theory predicts the item output sequence to be in the descending order of memory strength. The dual-retrieval process theory postulates two phases in a free recall, a first direct access phase in which items are output verbatim in the weakest-to-strongest order (cognitive triage) and a second reconstructive phase in which reconstructed items are output in the strongest-to-weakest order. In four experiments, all three indicators of memory strength (latency, accuracy, and confidence) consistently showed a descending-strength order of recall both for true and false memories. Additionally, false memory was found to be output in two phases and subjects’ confidence judgment of their own memory to be unaccountable by retrieval fluency (recall latency).

Recall of details never experienced: Effects of age, repetition, and semantic cues

To test theoretical predictions about the role of meaning connections in false memory, the effects of semantic cues and list repetition on children's false memories were evaluated across early childhood to mid-adolescence using the Deese–Roediger–McDermott (DRM) paradigm. True recall and false recall increased from 7 to 13 years. Study list repetition increased true recall of list words with the magnitude of this effect largest in the older children and adolescents. Repetition reduced false recall of critical lures in all age groups. Consistent with theoretical predictions, false recall of critical lures increased when children were informed of the thematic gist of each list prior to study.

Transfer of learning in avoiding false memory: The roles of warning, immediate feedback, and incentive

Participants learned semantic associates and were tested in the Deese-Roediger-McDermott (DRM) paradigm. A multiple-trial learning procedure with warning, feedback, and monetary incentive was employed to reduce false memory. Results showed that there was a progressive reduction of false memory over the trials as well as a generalization of learning to new lists of words in avoiding the critical nonpresented words attributable to explicit warning, feedback, and incentive, respectively. Both the feedback and the monetary incentive had an effect beyond what an explicit warning could obtain. In addition, participants were found to achieve false-memory reduction by enhancing the activation of the critical words and the monitoring process, rather than by strengthening the verbatim processing of the list words. It was concluded that false memory may not be as impervious to correction as was believed insofar as an effective training method is applied.

Neurophysiological correlates of memory illusion in both encoding and retrieval phases

False recognition of a critical lure at retrieval in the Deese–Roediger–McDermott (DRM) paradigm depends on different processing of its corresponding associates in the encoding phase. The current study recorded ERPs in both the encoding and retrieval phases to investigate the neural correlates of differential processing of true and false memories, and the roles of encoding and retrieval in eliciting memory illusion. The ERPs recorded at the study phase were characterized by a smaller N170 component and a larger amplitude late positive component (LPC) for associates that elicited later memory illusion than those that did not elicit later memory illusion. These ERP results suggest that increased active semantic associative processing or a gist representation was established for those items that elicited later memory illusion. This interpretation was supported by the serial-position analysis of the ERPs at encoding. Three ERP components were identified at retrieval. The equal early ERP old/new effects for true and false recognition reflected similar semantic priming. The parietal ERP old/new effect was greater for true than for false recognition, reflecting the recollection processes. A late slow negativity ERP distributed at the parietal and right frontal electrode sites differentiated between true and false recognition. The ERP results confirmed that both encoding and retrieval processes are involved in eliciting false memory. The parietal and frontal distributions of LPC at encoding and the late negativity at retrieval may imply a common neural mechanism in monitoring memory encoding and retrieval.

Effects of aging on true and false memory formation: An fMRI study

Compared to young, older adults are more likely to forget events that occurred in the past as well as remember events that never happened. Previous studies examining false memories and aging have shown that these memories are more likely to occur when new items share perceptual or semantic similarities with those presented during encoding. It is theorized that decreased item-specific encoding and increased gist encoding contribute to these age differences in memory performance. The current study used a modified version of the Deese–Roediger–McDermott (DRM) paradigm to investigate the neural correlates of true and false memory encoding. Results indicated that, compared to young, older adults showed reduced activity in medial temporal lobes (MTL), left ventrolateral prefrontal cortex (VLPFC), and visual cortices associated with subsequent true memories. Despite these decreases older adults showed increased activity in right VLPFC and left superior temporal gyrus (STG) for subsequent true memories. Age-related increases in STG were also associated with subsequent false memories. Results support the theory that older adults engage in less item-specific encoding and greater gist encoding, and that these increases in gist encoding support both subsequent true and false memories. Furthermore, results extend findings of reduced frontal asymmetry in aging, often found in block designs, to the subsequent memory paradigm. Results suggest that greater bilateral frontal activity during encoding in aging are not just task-related, but may be associated with subsequent successful memory performance.

The roles of spreading activation and retrieval mode in producing false recognition in the DRM paradigm

The nature of persisting spreading activation from list presentation in eliciting false recognition in the Deese–Roediger–McDermott (DRM) paradigm was examined in two experiments. We compared the time course of semantic priming in the lexical decision task (LDT) and false alarms in speeded recognition under identical study and test conditions. The results revealed priming on the LDT only when a test item occurred immediately (1 s) after the last list item. In contrast, robust false recognition occurred across all delays in both experiments. We interpret the data as indicating that the automatic activation processes evidenced in lexical decision do not persist sufficiently long to produce the false recognition obtained in the DRM paradigm. False recognition occurs because episodic retrieval instructions and a related probe item create reactivation of a list’s associative structure, but such reactivation does not occur in LDT under conditions in which subjects are discouraged from retrospective checking of the list.

Need for cognition and false memory in the Deese–Roediger–McDermott paradigm

Two experiments investigated whether false recognition in the Deese–Roediger–McDermott (DRM) paradigm is mediated by individual differences in need for cognition. In Experiment 1, participants were presented with word lists composed of associates which converge on a non-presented critical word. On a subsequent recognition test, high need for cognition participants falsely recognized a greater proportion of critical words as having been previously studied than did low need for cognition participants. Experiment 2 replicated Experiment 1, and also tested a manipulation of list strength. Word lists used were either strong or weak in terms of eliciting the critical item. These experiments show that individual differences in approach to information processing tasks can affect the rate of false memory elicited in the DRM task.

False memories produced by children and adults in the DRM paradigm

AbstractIn the Deese–Roediger–McDermott (DRM) paradigm, participants study a list of words (e.g., bed, rest, awake, dream) that are related to a critical target (i.e., sleep). When tested, participants often falsely report the critical target even though it was not on the original study list. Although this procedure has been used extensively with adults, few researchers have employed the DRM task with children. The present experiment explored how children and adults perform in the DRM paradigm when the length of the study list is manipulated. Children and adults studied eight DRM lists comprising either seven words (short‐list condition) or 14 words (long‐list condition). Adults recalled a larger proportion of studied words in both list length conditions. In the long‐list condition, adults falsely recalled significantly more critical targets than children. In the short‐list condition, rates of false recall did not differ. A similar pattern emerged in the recognition data, with adults obtaining a higher rate of false recognition than children in the long‐list condition, but not in the short list condition. Overall, long lists produced more false memories than short lists. We conclude that studying longer lists led to greater activation of the critical target in adults, whereas children received little additional activation from longer lists. Copyright © 2006 John Wiley & Sons, Ltd.

Stress-induced cortisol responses, sex differences, and false recollections in a DRM paradigm

The current studies investigated whether acute stress potentiates false recollections (so-called “false memories”) in a Deese–Roediger–McDermott (DRM) paradigm, and whether sex differences modulate these effects. Participants were assigned to either a stress (trier social stress test) or a control group. Subsequently, they were subjected to DRM word lists and probed for recall and recognition. Results showed no differences between the stress and control group on measures of false recollections (Study 1; N = 60). Even though correct recall was impaired by acute stress, there were no differences between high or low cortisol responders and controls on false recall or recognitions rates (Study 2; N = 92). These results suggest that cortisol responses do not directly potentiate false recollections. Neither in Study 1 nor in Study 2 did we find any evidence that the effects of cortisol on false recollections are different in men and women, although there was an indication that independent of stress men produced more commission errors.

False memories and delusional ideation in normal healthy subjects

Studies have reported substantial mnestic deficits in patients with schizophrenia. Most of this research, however, has focussed on errors of omission (poor recall/recognition) rather than commission (such as false recall/recognition). Nevertheless, recent studies report that schizophrenics show increased false recognition and speculate that this may underpin delusional ideation ( Moritz et al., 2004). No previous study has examined whether such memory problems exist in normal individuals who may be prone to delusional thinking. Using the Roediger and McDermott (1995) paradigm, we investigated memory functioning in 105 normal healthy subjects divided according to performance on a measure of delusional ideation (Peters et al. Delusional Inventory: PDI Peters et al., 1999). We found significantly poorer recall in the high than low PDI group. Moreover, high PDI scorers also made more false-alarm memory recalls than low PDI scorers. In a recognition test, high and low PDI subjects did not differ in the confidence they attached to recognition of studied items, but high PDI subjects gave greater confidence for falsely accepting unseen items. This suggests that healthy subjects scoring high on a measure of delusional thinking do show an increased tendency to make false positives, but not to make false negative memory judgements.

Fantasy proneness, but not self-reported trauma is related to DRM performance of women reporting recovered memories of childhood sexual abuse

Extending a strategy previously used by Clancy, Schacter, McNally, and Pitman (2000), we administered a neutral and a trauma-related version of the Deese–Roediger–McDermott paradigm to a sample of women reporting recovered ( n = 23) or repressed memories ( n = 16) of childhood sexual abuse (CSA), women reporting having always remembered their abuse ( n = 55), and women reporting no history of abuse ( n = 20). We found that individuals reporting recovered memories of CSA are more prone than other participants to falsely recalling and recognizing neutral words that were never presented. Moreover, our study is the first to show that this finding even held when trauma-related material was involved. Correlational analyses revealed that fantasy proneness, but not self-reported traumatic experiences and dissociative symptoms were related to false recall and false recognition.

Adult Age Differences in Distinctive Processing: The Modality Effect on False Recall.

Age differences in distinctive processing were investigated by examining the effects of study presentation modality on false recall in younger and older adults using the Deese/Roediger and McDermott paradigm. Participants were presented with study words either visually or auditorily. Older adults did not show the typical reduction in false recall after visual, compared to auditory, study presentation (R.E. Smith & R.R. Hunt, 1998). The authors interpret these results as evidence of reduced distinctive processing on the part of older adults.