Working memory predicts the rejection of false memories

The relationship between working memory capacity (WMC) and false memories in the memory conjunction paradigm was explored. Previous research using other paradigms has shown that individuals high in WMC are not as likely to experience false memories as low-WMC individuals, the explanation being that high-WMC individuals are better able to engage in source monitoring. In the memory conjunction paradigm participants are presented at study with parent words (e.g., eyeglasses, whiplash). At test, in addition to being presented with targets and foils, participants are presented with lures that are composed of previously studied features (e.g., eyelash). It was found that high-WMC individuals had lower levels of false recognition than low-WMC individuals. Furthermore, recall-to-reject responses were analysed (e.g., "I know I didn't see eyelash because I remember seeing eyeglasses") and it was found that high-WMC individuals were more likely to utilise this memory editing strategy, providing direct evidence that one reason that high-WMC individuals are not as prone to false memories is because they are better able to engage in source monitoring.     

Working memory predicts the rejection of false memories

The relationship between working memory capacity (WMC) and false memories in the memory conjunction paradigm was explored. Previous research using other paradigms has shown that individuals high in WMC are not as likely to experience false memories as low-WMC individuals, the explanation being that high-WMC individuals are better able to engage in source monitoring. In the memory conjunction paradigm participants are presented at study with parent words (e.g., eyeglasses, whiplash). At test, in addition to being presented with targets and foils, participants are presented with lures that are composed of previously studied features (e.g., eyelash). It was found that high-WMC individuals had lower levels of false recognition than low-WMC individuals. Furthermore, recall-to-reject responses were analysed (e.g., “I know I didn't see eyelash because I remember seeing eyeglasses”) and it was found that high-WMC individuals were more likely to utilise this memory editing strategy, providing direct evidence that one reason that high-WMC individuals are not as prone to false memories is because they are better able to engage in source monitoring.     

Individual differences in working memory capacity and divided attention in dichotic listening

The controlled attention theory of working memory suggests that individuals with greater working memory capacity (WMC) are better able to control or focus their attention than individuals with lesser WMC. This relationship has been observed in a number of selective attention paradigms including a dichotic listening task (Conway, Cowan, & Bunting, 2001) in which participants were required to shadow words presented to one ear and ignore words presented to the other ear. Conway et al. found that when the participant’s name was presented to the ignored ear, 65% of participants with low WMC reported hearing their name, compared to only 20% of participants with high WMC, suggesting greater selective attention on the part of high WMC participants. In the present study, individual differences in divided attention were examined in a dichotic listening task, in which participants shadowed one message and listened for their own name in the other message. Here we find that 66.7% of high WMC and 34.5% of low WMC participants detected their name. These results suggest that as WMC capacity increases, so does the ability to control the focus of attention, with high WMC participants being able to flexibly “zoom in” or “zoom out” depending on task demands.     

Eliciting false memories on implicit and explicit memory tests after incidental learning

Abstract: In a false memory experiment, lists of semantic associates (e.g., newspaper, letter, book, etc.) were presented to three groups of participants to induce false memories for critical nonpresented (CN) words (e.g., read) in an incidental learning task. The control group simply estimated the frequency rate in everyday Japanese discourse of each word on a list. The imagery instruction group received an additional instruction to imagine a thematically related converging word from the target words on a list. Participants in the imagery plus writing group received the same instructions as those in the imagery instruction group, but were also required to write down the word they imagined for each list. The results from the implicit and explicit memory tests given after the incidental learning episode showed that the level of priming for CN words was equivalent to that for actually presented target words for all three groups on the implicit test, whereas explicit memory results showed that participants explicitly recognized more target words than CN words. The implications for implicit associative response and fuzzy‐trace theories of false memory, as well as implicit priming, are discussed.     

Working memory capacity in generalized social phobia

Research suggests that understanding complex social cues depends on the availability of cognitive resources (e.g., Phillips, Channon, Tunstall, Hedenstrom, & Lyons, 2008). In spite of evidence suggesting that executive control functioning may impact anxiety (e.g., Eysenck, Derakshan, Santos, & Calvo, 2007), relatively few studies have examined working memory in individuals with generalized social phobia. Moreover, few studies have examined the role of threat-relevant content in working memory performance in clinically anxious populations. To this end, the present study assessed working memory capacity (WMC) in individuals with generalized social phobia and nonanxious controls using an operation span task with threat-relevant and neutral stimuli. Results revealed that nonanxious individuals demonstrated better WMC than individuals with generalized social phobia for neutral words but not for social threat words. Individuals with generalized social phobia demonstrated better WMC performance for threat words relative to neutral words. These results suggest that individuals with generalized social phobia may have relatively enhanced working memory performance for salient, socially relevant information. This enhanced working memory capacity for threat-relevant information may be the result of practice with this information in generalized social phobia.     

Advertising Effectiveness and Attitude Change Vary as a Function of Working Memory Capacity

Prior research has confirmed that the amount of attention paid to an advertisement will influence its effectiveness when it comes to changing consumer attitudes. This study expands on this understanding by exploring how individual differences in the ability to control attention (i.e., working memory capacity; WMC) might further moderate the effect of attention on advertising. Participants who varied in WMC were evaluated on their attitudes towards a consumer brand before and after viewing a video advertisement. While the advertisement did make participants more positive towards the product overall, this change in attitude was directly related to participants' ability to control attention and the degree to which the ad fostered the activation of autobiographical memories. Further, these changes in attitude were unrelated to how well the ad was remembered. This suggests that individual differences in attentional control can influence how advertisements impact customer attitude and the acceptance of persuasive messaging. Copyright © 2016 John Wiley & Sons, Ltd.     

False memories and fantastic beliefs: 15 years of the DRM illusion

This article reviews research using the Deese/Roediger—McDermott (DRM) associative memory illusion, whereby people falsely remember words that were not presented. This illusion has broadly influenced basic theories of memory in cognitive psychology and neuroscience and naturally raises the question as to how these theories apply to more complex autobiographical memories. Some applicability is evident from research linking individual differences in the DRM illusion to false autobiographical memories (e.g., misremembering public events) and fantastic autobiographical beliefs (e.g., memories from past lives). But which aspects generalize? Here it is argued that a process—oriented approach is needed in order to answer this question. Many productive years of DRM research indicate that multiple and often opposing psychological processes cause even the most basic false memories. In light of these discoveries, more researchers need to use methods that isolate these component processes if the goal is to understand false memories both in the lab and in life.     

Individual differences in recognising involuntary autobiographical memories: Impact on the reporting of abstract cues

This study examined individual differences in the ability to recognise involuntary autobiographical memories. We hypothesised that individuals may not always recognise involuntary memories which are cued by abstract experiences (e.g., thoughts or language), while they are better able to recognise those which are cued by concrete sensory/perpetual experiences. We hypothesised that individuals without formal training in psychology would be more prone to these recognition failures than individuals with training in psychology. We tested the hypothesis by comparing the results of general first-year undergraduate students, graduate students in psychology and graduates students in other disciplines after each had participated in a two-week diary study of their naturally occurring involuntary memories. The results showed undergraduate participants and non-psychology graduate participants reporting fewer involuntary memories being triggered by abstract cues than the graduate psychology participants, while the groups did not differ in the report of memories triggered by sensory/perpetual cues. The implications of the findings are discussed.     

Individual differences in working memory capacity and resistance to belief bias in syllogistic reasoning

In two experiments, we investigated the possibility that individual differences in working memory capacity (WMC) would provide resistance to belief bias in syllogistic reasoning. In Experiment 1 (N?=?157), participants showed a belief bias effect in that they had longer response times and decreased accuracy on syllogisms with conflict between the validity and believability of the conclusion than on syllogisms with no such conflict. However, this effect did not differ as a function of individual differences in WMC. Experiment 2 (N?=?122) replicated this effect with the addition of decontextualized (i.e., nonsense) syllogisms as a different means of measuring the magnitude of the belief bias effect. Although individual differences in WMC and fluid intelligence were related to better reasoning overall, the magnitude of the belief bias effect was not smaller for participants with greater WMC. The present study offers two novel findings: (a) The belief bias effect is independent of individual differences in WMC and fluid intelligence, and (b) resolving conflict in verbal reasoning is not a type of conflict resolution that correlates with individual differences in WMC, further establishing boundary conditions for the role of WMC in human cognitive processes.     

Individual differences in working memory capacity affect false memories for missing aspects of events

Recently, Gerrie, Belcher, and Garry (2006) found that, when participants watch an event with parts missing, they falsely claim to have seen the missing parts—but they were more likely to claim they had seen less crucial parts than more crucial parts. Their results fit with a source-monitoring framework (SMF; Johnson, Hashtroudi, & Lindsay, 1993) explanation of false memories. In this paper we used individual differences in working memory capacity (WMC) to examine the SMF explanation of false memories for missing aspects of events. An accumulating body of research suggests that WMC is strongly related to controlling attention, including the ability to distinguish between sources of information. The primary purpose of the present study was to examine whether people with larger WMC are better able to ward off false memories for missing information than those with a smaller WMC. We showed that higher WMC reduced false recognition of crucial information, but did not change false recognition of noncrucial information. Additionally, we found that WMC had little effect on participants’ subjective experience of true and false recognition of events, regardless whether the information was crucial or not. These results provide further evidence that people's WMC is related to their source-monitoring ability.     

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.     

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.     

Speech Intelligibility and Recall of Spoken Material Heard at Different Signal‐to‐noise Ratios and the Role Played by Working Memory Capacity

We studied speech intelligibility and memory performance for speech material heard under different signal‐to‐noise (S/N) ratios. Pre‐experimental measures of working memory capacity (WMC) were taken to explore individual susceptibility to the disruptive effects of noise. Thirty‐five participants first completed a WMC‐operation span task in quiet and later listened to spoken word lists containing 11 one‐syllable phonetically balanced words presented at four different S/N ratios (+12, +9, +6, and +3). Participants repeated each word aloud immediately after its presentation, to establish speech intelligibility and later on performed a free recall task for those words. The speech intelligibility function decreased linearly with increasing S/N levels for both the high‐WMC and low‐WMC groups. However, only the low‐WMC group had decreasing memory performance with increasing S/N levels. The memory of the high‐WMC individuals was not affected by increased S/N levels. Our results suggest that individual differences in WMC counteract some of the negative effects of speech noise. Copyright © 2012 John Wiley & Sons, Ltd.     

Individual differences in working memory capacity affect false memories for missing aspects of events

Recently, Gerrie, Belcher, and Garry (2006) found that, when participants watch an event with parts missing, they falsely claim to have seen the missing parts--but they were more likely to claim they had seen less crucial parts than more crucial parts. Their results fit with a source-monitoring framework (SMF; Johnson, Hashtroudi, & Lindsay, 1993) explanation of false memories. In this paper we used individual differences in working memory capacity (WMC) to examine the SMF explanation of false memories for missing aspects of events. An accumulating body of research suggests that WMC is strongly related to controlling attention, including the ability to distinguish between sources of information. The primary purpose of the present study was to examine whether people with larger WMC are better able to ward off false memories for missing information than those with a smaller WMC. We showed that higher WMC reduced false recognition of crucial information, but did not change false recognition of noncrucial information. Additionally, we found that WMC had little effect on participants' subjective experience of true and false recognition of events, regardless whether the information was crucial or not. These results provide further evidence that people's WMC is related to their source-monitoring ability.     

Variation in individuals' semantic networks for common knowledge is associated with false memory

Three experiments assessed the relationships between false memories of words and their degree of connectedness within individual semantic networks. In the first two experiments, participants studied associated word lists (e.g., hot, winter, ice), completed a recognition test that included related nonstudied words (e.g., cold, snow), and then rated the semantic relatedness of all word pairs including studied and nonstudied words. In the third experiment, the task order was reversed; participants completed pairwise ratings and then, two weeks later, completed the false memory task. The relatedness ratings were analysed using the Pathfinder scaling algorithm. In all experiments, items that an individual falsely recognized had higher semantic Pathfinder node densities than those items correctly rejected.     

Variation in individuals' semantic networks for common knowledge is associated with false memory

Three experiments assessed the relationships between false memories of words and their degree of connectedness within individual semantic networks. In the first two experiments, participants studied associated word lists (e.g., hot, winter, ice), completed a recognition test that included related nonstudied words (e.g., cold, snow), and then rated the semantic relatedness of all word pairs including studied and nonstudied words. In the third experiment, the task order was reversed; participants completed pairwise ratings and then, two weeks later, completed the false memory task. The relatedness ratings were analysed using the Pathfinder scaling algorithm. In all experiments, items that an individual falsely recognized had higher semantic Pathfinder node densities than those items correctly rejected.     

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.     

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.     

Implicit attitude generalization occurs immediately; explicit attitude generalization takes time

People are able to explicitly resist using knowledge about one person to evaluate another person from the same group. After learning about positive and negative behaviors performed by one individual from each of two different groups, participants were introduced briefly to new individuals from the groups. Implicit evaluations of the original individuals readily generalized to the new individuals; explicitly, participants resisted such generalization. Days later, both implicit and explicit evaluations of the original individuals generalized to the new individuals. The results suggest that associative links (e.g., shared group membership) are sufficient for implicit attitude generalization, but deliberative logic (e.g., individual group members are not necessarily the same) can reduce explicit generalization by association. When knowledge distinguishing who did what is unavailable, such as after forgetting, associative knowledge provides the basis of explicit evaluation. We conclude that a simple association linking one individual to another can produce implicit attitude generalization immediately and explicit attitude generalization eventually.     

Omitting details from post-event information: are true and false memory affected in the same way?

Participants who witness an event and later receive post-event information that omits a critical scene are less likely to recall and to recognise that scene than are participants who receive no post-event information (Wright, Loftus, & Hall, 2001). The present study used the Deese-Roediger-McDermott (DRM) paradigm, in which participants study lists of semantic associates (e.g., hot, snow, warm, winter) that commonly elicit false memories of critical non-presented words (e.g., cold), to determine whether omitting information from a second presentation decreases memory for both presented and non-presented information. Participants were presented with a list of the semantic associates of six non-presented words. For half the participants, this list was presented a second time with the semantic associates of one of the non-presented words omitted. As expected, participants were less likely to recall and to recognise the presented words when they had been omitted from the second presentation. Omission also decreased the rate at which non-presented words were recalled, although false recognition of these words was not reduced. These results suggest that false recognition may be particularly difficult to attenuate and that post-event omission may be more detrimental to memory accuracy than previously thought.