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

In 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.     

Imagery encoding and false recognition errors: Examining the role of imagery process and imagery content on source misattributions

Imagery encoding effects on source-monitoring errors were explored using the Deese-Roediger-McDermott paradigm in two experiments. While viewing thematically related lists embedded in mixed picture/word presentations, participants were asked to generate images of objects or words (Experiment 1) or to simply name the items (Experiment 2). An encoding task intended to induce spontaneous images served as a control for the explicit imagery instruction conditions (Experiment 1). On the picture/word source-monitoring tests, participants were much more likely to report "seeing" a picture of an item presented as a word than the converse particularly when images were induced spontaneously. However, this picture misattribution error was reversed after generating images of words (Experiment 1) and was eliminated after simply labelling the items (Experiment 2). Thus source misattributions were sensitive to the processes giving rise to imagery experiences (spontaneous vs deliberate), the kinds of images generated (object vs word images), and the ways in which materials were presented (as pictures vs words).     

Illusions of familiarity caused by cohort activation

Subjects took part in an auditory lexical decision task followed by an auditory test of recognition memory for words presented in this task. Subjects categorized their recognition judgments as based on either recollection (“remember” responses) or familiarity (“know” responses). Distractor items in the recognition test included the base words from which the nonwords used in the lexical decision task were derived. Consistent with the findings of Wallace, Stewart, Sherman, and Mellor (1995), more false alarms were made to “late” base words (where the corresponding nonwords were created by changing a phoneme near the end of the word) than to “early” base words (corresponding nonwords were created by changing a phoneme at the beginning of the word). However, this effect was found in “know” responses but not in “remember” responses. The findings are attributed to enhanced fluency with which the base words are processed following their implicit activation at encoding.     

Effects of survival processing and retention interval on true and false recognition in the DRM and category repetition paradigms

ABSTRACT

Two experiments examined the effects of survival processing and delay on true and related false recognition. Experiment 1 used the Deese-Roediger-McDermott paradigm and found survival processing to increase true and related false recognition. Extending the delay from 5-mins to 1-day reduced true, but not false memory. Measures of the characteristics of true and false memories showed survival processing increased “remember” and “know” responses for related false memory, “know” responses for true memory and gist processing. Experiment 2 made use of the category repetition procedure and found a broadly similar pattern of results for true memory. However, related false memory was decreased by survival processing. Except for one result, no interactions were found between encoding task and delay. Overall, survival processing produced similar or different effects on true/false memory depending on the nature of the list. The mechanisms that might underpin these are evaluated and considered in relation to future work.     

来源检测对表象引发的错误记忆的影响

采用“学习-再认”模式,考察来源检测对表象引发的错误记忆的影响。结果发现,在再认任务中,正确再认观察项目与想象项目的反应时差异不显著,但在源检测中,正确再认观察项目显著快于正确再认想象项目; 再认时与源检测时的错误再认率差异不显著,但对想象项目的错误再认率显著高于对观察项目。这表明,表象会导致错误记忆发生,提高来源检测操纵并不能够削弱表象引发的错误记忆。根据研究结果提出“表象激活混淆假设”,认为人们虽然使用表象的信息表征方式,却无法获取与之联系的激活路径,容易混淆表象激活的来源。表象激活混淆是表象引发错误记忆的机制。     

False recollection of the role played by an actor in an event

Two experiments demonstrated that eyewitnesses more frequently associate an actor with the actions of another person when those two people had appeared together in the same event, rather than in different events. This greater likelihood of binding an actor with the actions of another person from the same event was associated with high-confidence recognition judgments and “remember” responses in a remember–know task, suggesting that viewing an actor together with the actions of another person led participants to falsely recollect having seen that actor perform those actions. An analysis of age differences provided evidence that familiarity also contributed to false recognition independently of a false-recollection mechanism. In particular, older adults were more likely than young adults to falsely recognize a novel conjunction of a familiar actor and action, regardless of whether that actor and action were from the same or from different events. Older adults’ elevated rate of false recognition was associated with intermediate confidence levels, suggesting that it stemmed from increased reliance on familiarity rather than from false recollection. The implications of these results are discussed for theories of conjunction errors in memory and of unconscious transference in eyewitness testimony.     

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.     

A simulation of visual imagery

This paper describes an operational computer simulation of visual mental imagery in humans. The structure of the simulation was motivated by results of experiments on how people represent information in, and access information from, visual images. The simulation includes a “surface representation,” which is spatial and quasi-pictorial, and an underlying “deep representation,” which contains “perceptual” information encoding appearance plus “propositional” information describing facts about an object. The simulation embodies a theory of how surface images are generated from deep representations, and how surface images are processed when one accesses information embedded in them. The simulation also offers an account of various sorts of imagery transformations.     

Threat perception after the Boston Marathon bombings: The effects of personal relevance and conceptual framing

We examined how the Boston Marathon bombings affected threat perception in the Boston community. In a threat perception task, participants attempted to “shoot” armed targets and avoid shooting unarmed targets. Participants viewing images of the bombings accompanied by affectively negative music and text (e.g., “Terror Strikes Boston”) made more false alarms (i.e., more errors “shooting” unarmed targets) compared to participants viewing the same images accompanied by affectively positive music and text (e.g., “Boston Strong”) and participants who did not view bombing images. This difference appears to be driven by decreased sensitivity (i.e., decreased ability to distinguish guns from non-guns) as opposed to a more liberal bias (i.e., favouring the “shoot” response). Additionally, the more strongly affected the participant was by the bombings, the more their sensitivity was reduced in the negatively framed condition, suggesting that this framing was particularly detrimental to the most vulnerable individuals in the affected community.     

Source misattributions and false recognition errors: Examining the role of perceptual resemblance and imagery generation processes

In three experiments, we examine the extent to which participants’ memory errors are affected by the perceptual features of an encoding series and imagery generation processes. Perceptual features were examined by manipulating the features associated with individual items as well as the relationships among items. An encoding instruction manipulation was included to examine the effects of explicit requests to generate images. In all three experiments, participants falsely claimed to have seen pictures of items presented as words, committing picture misattribution errors. These misattribution errors were exaggerated when the perceptual resemblance between pictures and images was relatively high (Experiment 1) and when explicit requests to generate images were omitted from encoding instructions (Experiments 1 and 2). When perceptual cues made the thematic relationships among items salient, the level and pattern of misattribution errors were also affected (Experiments 2 and 3). Results address alternative views about the nature of internal representations resulting in misattribution errors and refute the idea that these errors reflect only participants’ general impressions or beliefs about what was seen.     

When plausibility manipulations work: An examination of their role in the development of false beliefs and memories

In the current study we examined whether prevalence information and imagery encoding influence participants' general plausibility, personal plausibility, belief, and memory ratings for suggested childhood events. Results showed decreases in general and personal plausibility ratings for low prevalence events when encoding instructions were not elaborate; however, instructions to repeatedly imagine suggested events elicited personal plausibility increases for low-prevalence events, evidence that elaborate imagery negated the effect of our prevalence manipulation. We found no evidence of imagination inflation or false memory construction. We discuss critical differences in researchers' manipulations of plausibility and imagery that may influence results of false memory studies in the literature. In future research investigators should focus on the specific nature of encoding instructions when examining the development of false memories.     

Mood-congruent false memories in the DRM paradigm

This study investigated the creation of mood-congruent false memories within the Deese–Roediger–McDermott (DRM) paradigm using recall and recognition of critical lures as performance measures. Participants (n=93) were randomly assigned to three mood-induction conditions (positive, negative and control) and were presented with positive, negative and neutral DRM word lists in audio form. We predicted that intrusion errors of the critical lures would be higher in the mood-congruent conditions. Results confirmed this prediction and extended previous DRM research by showing that already high false memory rates were increased when the valence of the lures matched the mood-induction condition. Furthermore, participants made more “remember” judgements for the emotion critical lures in their mood-congruent conditions. Discussion draws on spreading activation explanations of DRM findings, and considers how moods could increase activation of non-presented information.