Importing perceived features into false memories

Representation of shared surface information and false memory for abstract versus concrete pictures in the conjoint recognition paradigm

An effective factor by which false memories can arise is relatedness which includes not only semantic associations but also perceptual resemblance. This issue raises questions about how patterns of perceptual features are represented in memory and how they relate to semantic representations. In five experiments, we investigated the memory processes underlying the false recognition of perceptually or semantically related pictures from the perspective of fuzzy trace theory. Multinomial processing tree model analyses for the conjoint recognition paradigm showed that the parameter representing gist trace retrieval not only contributes to false acceptances of semantically related pictures, but also underlies the false recognition of non-semantically related abstract shapes. These results challenged the hypothesis that the false recognition of non-semantically related distractors is solely due to interference with the verbatim suppression process. These experiments also showed that adding a surface feature (colour) to the category exemplars increases false recognition of related distractors by enhancing the contribution of the familiarity process, but only for pictures of real objects. Comparisons between experiments showed that different variants of the conjoint recognition model, used to analyse the effects of the same experimental manipulation, can lead to partially different conclusions.

False memory-guided eye movements: insights from a DRM-Saccade paradigm

The Deese-Roediger and McDermott (DRM) paradigm and visually guided saccade tasks are both prominent research tools in their own right. This study introduces a novel DRM-Saccade paradigm, merging both methodologies. We used rule-based saccadic eye movements whereby participants were presented with items at test and were asked to make a saccade to the left or right of the item to denote a recognition or non-recognition decision. We measured old/new recognition decisions and saccadic latencies. Experiment 1 used a pro/anti saccade task to a single target. We found slower saccadic latencies for correct rejection of critical lures, but no latency difference between correct recognition of studied items and false recognition of critical lures. Experiment 2 used a two-target saccade task and also measured corrective saccades. Findings corroborated those from Experiment 1. Participants adjusted their initial decisions to increase accurate recognition of studied items and rejection of unrelated lures but there were no such corrections for critical lures. We argue that rapid saccades indicate cognitive processing driven by familiarity thresholds. These occur before slower source-monitoring is able to process any conflict. The DRM-Saccade task could effectively track real-time cognitive resource use during recognition decisions.

Context-dependent memory recall in HMD-based immersive virtual environments

The article introduces an original VR-based experiment which explores context-dependent memory recall in humans. It specifically examines the recall of correct and falsely induced semantic memories. With the aid of VR head-mounted displays, 92 students of psychology were placed in a computer-generated indoor virtual environment and asked to memorize the presented lists of words. Afterwards, the participants were placed in the same indoor virtual environment or an alternative outdoor virtual environment and asked to recall the words. The number of correct and falsely induced words was then measured. On average, women recalled significantly more correct words from the list than men, regardless of the environmental context. Despite the assumptions, we did not observe a separate effect of exposure to different environments during learning and recall of material on memory performance. Likewise, we did not detect any effects of the learning context or biological sex in the case of the production of false memories. These results provide a novel insight into previous knowledge regarding the memory processes that occur in virtual environments. Although we failed to confirm the role of context in recalling learned material in general, we found a hint that this context might interact with specific memory processes of biological sexes. However, the design of this study only captured the effect of changing the environment during memory recall and did not address the role of specific context in remembering learning material. Further research is therefore needed to better investigate these phenomena and examine the role of biological sex in context-dependent memory processes.

False memory confidence depends on the prefrontal reinstatement of true memory

For confidence of memory, a neural basis such as traces of stored memories should be required. However, because false memories have never been stored, the neural basis for false memory confidence remains unclear. Here we monitored the brain activity in participants while they viewed learned or novel objects, subsequently decided whether each presented object was learned and assessed their confidence levels. We found that when novel objects are presented, false memory confidence significantly depends on the shared representations with learned objects in the prefrontal cortex. However, such a tendency was not found in posterior regions including the visual cortex, which may be involved in the processing of perceptual gist. Furthermore, the confidence-dependent shared representations were not observed when participants correctly answered novel objects as non-learned objects. These results demonstrate that false memory confidence is critically based on the reinstatement of high-level semantic gist of stored memories in the prefrontal cortex.

Playing "guess who?": when an episodic specificity induction increases trace distinctiveness and reduces memory errors during event reconstruction

The constructive nature of memory implies a possible confusion between details of similar events. Memory interventions should thus target the reduction of memory errors. We postulate that a brief intervention called Episodic Specificity Induction (ESI) facilitates the sensorimotor simulation of event-related details by improving the distinctiveness of the event memory trace. As such, ESI should reduce memory errors only when event memory traces are strongly overlapping based on their sensorimotor features. Participants memorised videos showing characters performing an action on a given object. The characters were either visually very similar to each other or very distinct (low vs. high distinctiveness condition). Next, participants performed either an imagination version of the ESI or a control induction. Finally, a voice announced one of the actions seen and a character was then briefly displayed. The participants had to indicate whether the association was correct. For incorrect associations, in the low distinctiveness condition, false alarms were more likely than in the high distinctiveness condition and were reduced after the ESI. It suggests that facilitating the simulation of specific details through the ESI increased trace distinctiveness and reduced memory errors at the critical time of event reconstruction. Future clinical applications might be possible.

The relative contribution of shape and colour to object memory

The current studies examined the relative contribution of shape and colour in object representations in memory. A great deal of evidence points to the significance of shape in object recognition, with the role of colour being instrumental under certain circumstances. A key but yet unanswered question concerns the contribution of colour relative to shape in mediating retrieval of object representations from memory. Two experiments (N=80) used a new method to probe episodic memory for objects and revealed the relative contribution of colour and shape in recognition memory. Participants viewed pictures of objects from different categories, presented one at a time. During a practice phase, participants performed yes/no recognition with some of the studied objects and their distractors. Unpractised objects shared shape only (Rp–Shape), colour only (Rp–Colour), shape and colour (Rp–Both), or neither shape nor colour (Rp–Neither), with the practised objects. Interference effects in memory between practised and unpractised items were revealed in the forgetting of related unpractised items – retrieval-induced forgetting. Retrieval-induced forgetting was consistently significant for Rp–Shape and Rp–Colour objects. These findings provide converging evidence that colour is an automatically encoded object property, and present new evidence that both shape and colour act simultaneously and effectively to drive retrieval of objects from long-term memory.

Creating emotional false recollections: Perceptual recombination and conceptual fluency mechanisms

We investigated the impact of 2 hypothetical mechanisms of episodic memory reconstruction-perceptual recombination and conceptual fluency-on objectively measured recollection accuracy and false recollections of neutral and emotional stimuli. Participants encoded negative, neutral, and positive pictures depicting objects and scenes (i.e., target pictures), each accompanied with a descriptive verbal label (e.g., "boy crying at funeral," "wooden basket on floor," "four chimpanzees laughing together"). Next, they encoded fragmented pictures of some of the scenes they did and did not earlier see (perceptual misinformation), or they received multiple presentations of the corresponding verbal labels (conceptual misinformation). Recollection of target pictures was then tested, using labels as retrieval cues. We had three key findings in each of two experiments. First, as in our prior work, both perceptual and conceptual misinformation significantly increased false recollection judgments of nonstudied pictures, including high-confidence errors. These effects implicate perceptual recombination and conceptual fluency mechanisms. Second, these misinformation effects generalized across all emotional categories, implicating separable roles of these two mechanisms on emotional recollections. Finally, conceptual misinformation was less likely to influence negative than neutral recollection errors, providing new evidence that emotion can improve retrieval monitoring accuracy and reduce false memories based on conceptual fluency (i.e., an emotional distinctiveness heuristic). (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Reduced impact of imagery processing on false autobiographical recollection: the effects of dynamic visual noise

Research has demonstrated that merely imagining an autobiographical event can bring about false memories for that event. One explanation for this is that imagination leads to the creation and incorporation of visual-imagistic information into the event representation. This idea was tested in two experiments in which visual-imagery processing was disrupted by the use of Dynamic Visual Noise (DVN). In Experiment 1, autobiographical memories that were rated as "known" and lacking in event detail were subsequently rated as more "remembered" following imagination. In Experiment 2, imagination led to improbable autobiographical events being rated as more believable and vivid. In both experiments, interfering with imagery processing by DVN reduced these effects. It was concluded that visual-imagistic processing plays an important role in altering the mnemonic status of autobiographical representations.

Looking forward: the effects of photographs on the qualities of future thinking

Future episodic thinking relies on the reconstruction of remembered experiences. Photographs provide one means of remembering, acting as a "cognitive springboard" for generating related memory qualities. We wondered whether photographs would also invite embellishment of future thought qualities, particularly in the presence (or absence) of associated memories. In two studies participants generated future events in familiar (associated memories) and novel (no associated memories) locations. Half of the participants viewed scene location photographs during event generation. All participants then imagined the events for one minute and completed a self-report measure of content qualities. Results of the current set of studies suggested that for novel locations, no differences in qualities emerged; however, for familiar locations, photographs did not enhance qualities and, in some cases, actually constrained perceptual (Experiments 1 and 2) and sensory (Experiment 1) detail ratings of future thoughts. Thus, photographs did not invite embellishment of future thought details.

Autobiographical memory conjunction errors in younger and older adults: Evidence for a role of inhibitory ability

Because of its reconstructive nature, autobiographical memory (AM) is subject to a range of distortions. One distortion involves the erroneous incorporation of features from one episodic memory into another, forming what are known as memory conjunction errors. Healthy aging has been associated with an enhanced susceptibility to conjunction errors for laboratory stimuli, yet it is unclear whether these findings translate to the autobiographical domain. We investigated the impact of aging on vulnerability to AM conjunction errors, and explored potential cognitive processes underlying the formation of these errors. An imagination recombination paradigm was used to elicit AM conjunction errors in young and older adults. Participants also completed a battery of neuropsychological tests targeting relational memory and inhibition ability. Consistent with findings using laboratory stimuli, older adults were more susceptible to AM conjunction errors than younger adults. However, older adults were not differentially vulnerable to the inflating effects of imagination. Individual variation in AM conjunction error vulnerability was attributable to inhibitory capacity. An inability to suppress the cumulative familiarity of individual AM details appears to contribute to the heightened formation of AM conjunction errors with age. (PsycINFO Database Record

Individual differences in susceptibility to false memories: The effect of memory specificity

Previous research has highlighted the wide individual variability in susceptibility to the false memories produced by the Deese/Roediger-McDermott (DRM) procedure. This study investigated whether susceptibility to false memories is influenced by individual differences in the specificity of autobiographical memory retrieval. Memory specificity was measured using the Sentence Completion for Events from the Past Test (SCEPT). Memory specificity did not correlate with correct recognition, but a specific retrieval style was positively correlated with levels of false recognition. It is proposed that the contextual details that frequently accompany false memories of non-studied lures are more accessible in individuals with specific retrieval styles.

Brain Mechanisms of Reality Monitoring

Reality monitoring processes are necessary for discriminating between internally generated information and information that originated in the outside world. They help us to identify our thoughts, feelings, and imaginations, and to distinguish them from events we may have experienced or have been told about by someone else. Reality monitoring errors range from confusions between real and imagined experiences, that are byproducts of normal cognition, to symptoms of mental illness such as hallucinations. Recent advances support an emerging neurocognitive characterization of reality monitoring that provides insights into its underlying operating principles and neural mechanisms, the differing ways in which impairment may occur in health and disease, and the potential for rehabilitation strategies to be devised that might help those who experience clinically significant reality monitoring disruption.

The retrieval context of intervening tasks influences subsequent memory in younger and older adults

BACKGROUND/STUDY CONTEXT: What people remember can be shaped by how they access and evaluate their memories as well as by events that happen after the original experience. This study examined how thinking about events in different ways after their occurrence can influence younger and older adults' memory for what really occurred.

METHODS

Younger adults (ages 18-22) and older adults (ages 65-88) saw and imagined pictures of objects and later evaluated each object 0, 1, or 3 times on a task that either required them to remember the objects in a general way (old or new?), in a more specific manner (perceived, imagined, or new?), or that required thinking about objects without regard to whether or how they were earlier experienced (e.g., judging their function or frequency in everyday life).

RESULTS

RESULTS showed that probing items multiple times on the intervening tasks increased the number of items younger and older adults successfully remembered later but also increased source misattributions of claiming to have seen objects that were really imagined, with older adults showing lower recall but higher source errors. Exposure to items on the nonretrieval intervening tasks negatively affected later source memory, and remembering items without explicitly considering their source increased source errors even more that did the non-retrieval-based intervening tasks.

CONCLUSIONS

These findings illustrate the negative impact of thinking about and nondiscriminately remembering past events on subsequent memory accuracy.

If I imagine it, then it happened: the Implicit Truth Value of imaginary representations

Imagination sometimes leads people to behave, feel, and think as though imagined events were real even when they know they were not. In this paper, we suggest that some understanding of these phenomena can be achieved by differentiating between Implicit Truth Value (ITV), a spontaneous truth evaluation, and Explicit Truth Value (ETV), a self-reported truth judgment. In three experiments, we measure ITV using the autobiographical Implicit Association Test (Sartori, Agosta, Zogmaister, Ferrara, & Castiello, 2008), which has been used to assess which of two autobiographical events is true. Our findings demonstrate that imagining an event, like experiencing an event, increases its ITV, even when people explicitly acknowledge the imagined event as false (Experiments 1a and 1b). Furthermore, we show that imagined representations generated from a first-person perspective have higher ITV than imagined representations generated from a third-person perspective (Experiment 2). Our findings suggest that implicit and explicit measures of truth differ in their sensitivity to properties underlying truth judgment. We discuss the contribution of characterizing events according to both ITV and ETV to the understanding of various psychological phenomena, such as lying and self-deception.

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.

Judging the reality of others' memories

Interpersonal reality monitoring (IRM) refers to our ability to evaluate whether other people's memories reflect real or imagined events. The current work examined IRM and whether or not it can be affected by training and feedback. We found that people are better than chance and that the ability to accurately make this judgement can be improved or reduced with appropriate and inappropriate training, respectively. Understanding IRM has implications for applied psychologists interested in how people evaluate others' descriptions of past events (e.g., eyewitness testimony).

The schema provokes a disparity of false recollection between actions and objects in an everyday scene

We explored the effect of the schema on recognition memories and subjective experiences for actions and objects in an everyday scene. At first, participants watched slides of a man cooking in a kitchen. The man performed schema-consistent actions, and schema-consistent objects were left. After watching the slides, participants completed a recognition test, a remember/know test, and a Perception/Thought/Emotion/Context questionnaire. We confirmed three main results. First, participants made more false recognitions for schema-consistent distracters than for schema-inconsistent distracters with more "remember" judgments accompanied by perceptual, thought, and contextual details, and with more "know" judgments. Second, participants made more false recognitions for schema-consistent object distracters than for schema-consistent action distracters. Third, participants more frequently recognized schema-consistent action targets than schema-consistent object targets with more "remember" judgments. Both action memory and object memory were reconstructed under the schema, provoking false recognitions for schema-consistent distracters. However, the memories of schema-consistent action targets were so recollective that they could prevent false recognitions for schema-consistent action distracters.

Negative effects of item repetition on source memory

In the present study, we explored how item repetition affects source memory for new item-feature associations (picture-location or picture-color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item repetition also had a negative effect on source memory when different source dimensions were used in Phases 1 and 2 (Experiment 3) and when participants were explicitly instructed to learn source information in Phase 2 (Experiments 4 and 5). Importantly, when the order between Phases 1 and 2 was reversed, such that item repetition occurred after the encoding of critical item-source combinations, item repetition no longer affected source memory (Experiment 6). Overall, our findings did not support predictions based on item predifferentiation, within-dimension source interference, or general interference from multiple traces of an item. Rather, the findings were consistent with the idea that prior item repetition reduces attention to subsequent presentations of the item, decreasing the likelihood that critical item-source associations will be encoded.

False recognition of objects in visual scenes: findings from a combined direct and indirect memory test

We report an extension of the procedure devised by Weinstein and Shanks (Memory & Cognition 36:1415-1428, 2008) to study false recognition and priming of pictures. Participants viewed scenes with multiple embedded objects (seen items), then studied the names of these objects and the names of other objects (read items). Finally, participants completed a combined direct (recognition) and indirect (identification) memory test that included seen items, read items, and new items. In the direct test, participants recognized pictures of seen and read items more often than new pictures. In the indirect test, participants' speed at identifying those same pictures was improved for pictures that they had actually studied, and also for falsely recognized pictures whose names they had read. These data provide new evidence that a false-memory induction procedure can elicit memory-like representations that are difficult to distinguish from "true" memories of studied pictures.

Imagery encoding and false recognition errors: exploring boundary conditions of imagery's enhancing effects

After generating images based on descriptions of object interactions, false recognition errors can be substantially reduced in the Deese-Roediger-McDermott (DRM) task. Boundary conditions for this effect were examined in three experiments by testing imagery encoding tasks against encoding tasks used previously to alter false recognition levels. False recognition errors were lowest following imagery encoding whether comparisons involved an object interaction encoding task used previously (Experiments 1 and 2) or a new version of the task (Experiment 2). In addition reductions in false recognition errors were observed in a new imagery-encoding task (Experiment 3). Generating descriptions had differential effects on "remember" responses to falsely recognised items (Experiment 2). In combination with content analyses on participants' descriptions, these findings speak to alternative explanations for the effects of imagery encoding on false recognition errors. The findings also have implications for the use of DRM results in developing recommendations regarding the use of guided imagery in applied contexts.

Seeing photos makes us read between the lines: The influence of photos on memory for inferences

Three studies examined how photos accompanying stories could contribute to people drawing inferences about outcomes from the stories and subsequently claiming that they had read what had actually only been inferred. Subjects read short stories designed to induce inferences about their conclusions (e.g., “Sabrina dropped the delicate vase” invites the inference that the vase broke) accompanied by a photo depicting the likely conclusion (the broken vase), a photo depicting a detail of the story but not the conclusion (the vase before it was dropped), or no photo. Results showed that seeing photographs consistent with inferred conclusions led people to falsely claim that they read those conclusions. Photo-boosted inferences were held with high confidence and were robust over time. Falsely recalled inferences were sometimes accompanied by false claims to have seen a photo depicting the inferred events when another photo or no photo had actually be seen. These findings support the source monitoring framework's prediction that people can mistakenly attribute their internally generated inferences about what occurred to externally derived sources when they have photographic “evidence” consistent with the inferred conclusions.

Whatever gave you that idea? False memories following equivalence training: a behavioral account of the misinformation effect

The misinformation effect is a term used in the cognitive psychological literature to describe both experimental and real-world instances in which misleading information is incorporated into an account of an historical event. In many real-world situations, it is not possible to identify a distinct source of misinformation, and it appears that the witness may have inferred a false memory by integrating information from a variety of sources. In a stimulus equivalence task, a small number of trained relations between some members of a class of arbitrary stimuli result in a large number of untrained, or emergent relations, between all members of the class. Misleading information was introduced into a simple memory task between a learning phase and a recognition test by means of a match-to-sample stimulus equivalence task that included both stimuli from the original learning task and novel stimuli. At the recognition test, participants given equivalence training were more likely to misidentify patterns than those who were not given such training. The misinformation effect was distinct from the effects of prior stimulus exposure, or partial stimulus control. In summary, stimulus equivalence processes may underlie some real-world manifestations of the misinformation effect.

False recognition and source attribution for actions of an emotional event in older and younger adults

In two experiments recognition of actions of a robbery presented in a video was examined in older and younger adults. In both experiments older adults had more false alarms and showed less accurate recognition than younger adults. In addition, when participants were asked in Experiment 1 to indicate Remember/Know/Guess judgments for actions they considered true, older adults accepted more false actions with Remember judgments. And when participants were asked in Experiment 2 to attribute the source (i.e., perpetrator), the older adults were less able to attribute actions that occurred during the robbery to their correct sources. Furthermore, we found a robust positive correlation between source attribution ability and recognition accuracy. Thus, source-memory deficits may contribute to older adults' false memories in real-life eyewitness situations.

False Memories for Suggestions: The Impact of Conceptual Elaboration

Relatively little attention has been paid to the potential role that reflecting on the meaning and implications of suggested events (i.e., conceptual elaboration) might play in promoting the creation of false memories. Two experiments assessed whether encouraging repeated conceptual elaboration, would, like perceptual elaboration, increase false memory for suggested events. Results showed that conceptual elaboration of suggested events more often resulted in high confidence false memories (Experiment 1) and false memories that were accompanied by the phenomenal experience of remembering them (Experiment 2) than did surface-level processing. Moreover, conceptual elaboration consistently led to higher rates of false memory than did perceptual elaboration. The false memory effects that resulted from conceptual elaboration were highly dependent on the organization of the postevent interview questions, such that conceptual elaboration only increased false memory beyond surface level processing when participants evaluated both true and suggested information in relation to the same theme or dimension.

Anchoring effects in the development of false childhood memories

When people receive descriptions or doctored photos of events that never happened, they often come to remember those events. But if people receive both a description and a doctored photo, does the order in which they receive the information matter? We asked people to consider a description and a doctored photograph of a childhood hot air balloon ride, and we varied which medium they saw first. People who saw a description first reported more false images and memories than did people who saw a photo first, a result that fits with an anchoring account of false childhood memories.

The effects of cognitive activity and perceptual details on speech source monitoring

Our purpose in this study was to investigate the effects of cognitive operations and perceptual details on speech source monitoring. In Phase 1, correctly spelled words and anagrams were presented in Expt 1. Words were read aloud by participants, by a same-sex voice, or by an opposite-sex voice. Immediately after Phase 1, in Phase 2, participants were asked whether each word had been read aloud by the participants themselves, by a same-sex voice, or by an opposite-sex voice. Source discrimination between own speech and that produced by a same-sex voice was poorer than between own speech and an opposite-sex voice. In addition, misattribution of the speech of another to one's self increased as the level of cognitive effort required for the task increased. In Expt 2, misattributions to same-sex voice were assigned 'know' responses more frequently and misattributions to one's self were assigned 'remember' responses more frequently. These results suggest that qualitative characteristics such as perceptual detail and cognitive operations are differentially influencing misattributions to the self and those to same-sex voices.

Source monitoring 15 years later: what have we learned from fMRI about the neural mechanisms of source memory?

Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral information, the article considers studies assessing the qualitative characteristics of memories, the encoding and remembering of emotional information, and false memories, as well as evidence from populations that show disrupted source memory (older adults, individuals with depression, posttraumatic stress disorder, or schizophrenia). Although there is still substantial work to be done, fMRI is advancing understanding of source memory and highlighting unresolved issues. A continued 2-way interaction between cognitive theory, as illustrated by the source monitoring framework (M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993), and evidence from cognitive neuroimaging studies should clarify conceptualization of cognitive processes (e.g., feature binding, retrieval, monitoring), prior knowledge (e.g., semantics, schemas), and specific features (e.g., perceptual and emotional information) and of how they combine to create true and false memories.

Dissociation between memory accuracy and memory confidence following bilateral parietal lesions

Numerous functional neuroimaging studies have observed lateral parietal lobe activation during memory tasks: a surprise to clinicians who have traditionally associated the parietal lobe with spatial attention rather than memory. Recent neuropsychological studies examining episodic recollection after parietal lobe lesions have reported differing results. Performance was preserved in unilateral lesion patients on source memory tasks involving recollecting the context in which stimuli were encountered, and impaired in patients with bilateral parietal lesions on tasks assessing free recall of autobiographical memories. Here, we investigated a number of possible accounts for these differing results. In 3 experiments, patients with bilateral parietal lesions performed as well as controls at source recollection, confirming the previous unilateral lesion results and arguing against an explanation for those results in terms of contralesional compensation. Reducing the behavioral relevance of mnemonic information critical to the source recollection task did not affect performance of the bilateral lesion patients, indicating that the previously observed reduced autobiographical free recall might not be due to impaired bottom-up attention. The bilateral patients did, however, exhibit reduced confidence in their source recollection abilities across the 3 experiments, consistent with a suggestion that parietal lobe lesions might lead to impaired subjective experience of rich episodic recollection.

Effects of Aging on Associative Memory for Related and Unrelated Pictures

Associative memory deficits are pervasive with age. Memory for complex pictures, however, also seems to require the association of several scene elements into one representation, but picture memory is often age-invariant. We speculated that the natural relationships contained in pictures may explain this distinction and that memory for scenes with unusual novel relationships would be affected with aging. In three experiments, we found that, counter to our predictions, the relatedness of scene elements exerted little influence on picture memory and did not differentially affect older compared to younger adults. These data suggest that the semantically rich associations contained in pictures need not rely on prior knowledge and experiences in order to support age-invariant picture memory. Our results indicate that associative memory for complex pictures may differ from memory for inter-item associations, which may be more affected by aging.

Recalling a Witnessed Event Increases Eyewitness Suggestibility

People's later memory of an event can be altered by exposure to misinformation about that event. The typical misinformation paradigm, however, does not include a recall test prior to the introduction of misinformation, contrary to what real-life eyewitnesses encounter when they report to a 911 operator or crime-scene officer. Because retrieval is a powerful memory enhancer (the testing effect), recalling a witnessed event prior to receiving misinformation about it should reduce eyewitness suggestibility. We show, however, that immediate cued recall actually exacerbates the later misinformation effect for both younger and older adults. The reversed testing effect we observed was based on two mechanisms: First, immediate cued recall enhanced learning of the misinformation; second, the initially recalled details became particularly susceptible to interference from later misinformation, a finding suggesting that even human episodic memory may undergo a reconsolidation process. These results show that real-life eyewitness memory may be even more susceptible to misinformation than is currently envisioned.