Fade In, Fade Out: Do Shifts in Visual Perspective Predict the Consistency of Real-World Memories?

Memories of our personal past are not exact accounts of what occurred. Instead, memory reconstructs the past in adaptive-though not always faithful-ways. Using a naturalistic design, we asked how the visual perspective adopted in the mind's eye when recalling the past-namely, an "own eyes" versus "observer" perspective-relates to the stability of autobiographical memories. We hypothesized that changes in visual perspective over time would predict poorer consistency of memories. Young adults (N = 178) rated the phenomenology of and freely recalled self-selected memories of everyday events at two time points (10 weeks apart). Multilevel linear modeling revealed, as expected, that greater shifts in visual perspective over time predicted lower memory consistency, particularly for emotional details. Our results offer insight into the factors that predict the fidelity of memories for everyday events. Moreover, our results may elucidate new metrics that are useful in interpreting eyewitness testimony or experiences relayed in clinical contexts.

Common and distinct correlates of construction and elaboration of episodic-autobiographical memory: An ALE meta-analysis.

The recollection of episodic-autobiographical memories (EAMs) entails a complex temporal dynamic, from initial "construction" to subsequent "elaboration" of memories. While there is consensus that EAM retrieval involves a distributed network of brain regions, it is still largely debated which regions specifically contribute to EAM construction and/or elaboration. To clarify this issue, we conducted an Activation Likelihood Estimation (ALE) meta-analysis based on the Preferred Reporting Items for Systematic-Reviews and Meta-Analyses (PRISMA) method. We found common recruitment of the left hippocampus and posterior cingulate cortex (PCC) during both phases. Additionally, EAM construction led to activations in the ventromedial prefrontal cortex, left angular gyrus (AG), right hippocampus, and precuneus, while the right inferior frontal gyrus was activated by EAM elaboration. Although most of these regions are distributed over the default mode network, the current findings highlight a differential contribution according to early (midline regions, left/right hippocampus, and left AG) versus later (left hippocampus, and PCC) recollection. Overall, these findings contribute to clarify the neural correlates that support the temporal dynamics of EAM recollection.

How shifting visual perspective during autobiographical memory retrieval influences emotion: A change in retrieval orientation.

Visual perspective during autobiographical memory (AM) retrieval influences how people remember the emotional aspects of memories. Prior research in emotion regulation has also shown that shifting from an own eyes to an observer-like perspective is an efficient way of regulating the affect elicited by emotional AMs. However, the impact of shifting visual perspective is also dependent on the nature of the emotion associated with the event. The current review synthesizes behavioral and functional neuroimaging findings from the event memory and emotion regulation literature that examine how adopting particular visual perspectives and actively shifting across them during retrieval alters emotional experience, by primarily focusing on emotional intensity. We review current theories explaining why shifts in perspectives may or may not change the emotional characteristics of memories, then propose a new theory, suggesting that the own eyes and observer-like perspectives are two different retrieval orientations supported by differential neural activations that lead episodic details to be reconstructed in specific ways.

Remembering a Virtual Museum Tour: Viewing Time, Memory Reactivation, and Memory Distortion.

A variety of evidence demonstrates that memory is a reconstructive process prone to errors and distortions. However, the complex relationship between memory encoding, strength of memory reactivation, and the likelihood of reporting true or false memories has yet to be ascertained. We address this issue in a setting that mimics a real-life experience: We asked participants to take a virtual museum tour in which they freely explored artworks included in the exhibit, while we measured the participants' spontaneous viewing time of each explored artwork. In a following memory reactivation phase, participants were presented again with explored artworks (reactivated targets), followed by novel artworks not belonging to the same exhibit (activated lures). For each of these objects, participants provided a reliving rating that indexed the strength of memory reactivation. In the final memory recognition phase, participants underwent an old/new memory task, involving reactivated vs. baseline (i.e., non-reactivated) targets, and activated and baseline lures. The results showed that those targets that were spontaneously viewed for a longer amount of time were more frequently correctly recognized. This pattern was particularly true for reactivated targets associated with greater memory strength (a higher reliving rating). Paradoxically, however, lures that were presented after targets associated with higher reliving ratings in the reactivation phase were more often erroneously recognized as artworks encountered during the tour. This latter finding indicates that memory intrusions, irrespective of the viewing time, are more likely to take place and be incorporated into true memories when the strength of target memory is higher.

The influence of shifting perspective on episodic and semantic details during autobiographical memory recall.

Shifting to a novel visual perspective during retrieval influences autobiographical memories (AM) and can lead to persistent changes in memories. Adopting an observer-like compared to an own eyes perspective reduces episodic information during AM recall, but less is known regarding how viewpoint influences semantic information. In the current study, we investigated how shifting from an own eyes to an observer-like perspective during narrative recall of AMs influences episodic and semantic information. Shifting perspective reduced the number of episodic details associated with emotions and thoughts, and also led to similar reductions in personal semantics. We replicated prior research showing that shifting perspective reduces emotional intensity in subsequent memories, but these subjective changes were not coupled with objective changes in a narrative recall. Our findings suggest that shifting perspective influences the interplay between episodic and semantic information during proximate recall and subjective changes when memories are later recalled.

Episodic-semantic interactions in spontaneous thought.

The distinction between a semantic memory system, encompassing conceptual knowledge, and an episodic memory system, characterized by specific episodes, is one of the most important theoretical proposals in cognitive science. However, the distinction between systems has rarely been discussed in relation to spontaneous thought that comes to mind with reduced cognitive effort and intentionality. In this review, we propose that the growing research on spontaneous thought can contribute to current discussions on the interaction between the episodic and semantic systems. Firstly, we review research that shows that, as in deliberate retrieval, spontaneous thoughts are influenced by both episodic and semantic memory, as reflected by the mix of semantic and episodic elements in descriptions of spontaneous thoughts, as well as semantic priming effects in spontaneous thoughts. We integrate the current evidence based on the interplay between cues and semantic activation. Namely, we suggest that cues are key to access episodic memory and modulate the frequency of spontaneous thought, while semantic activation modulates the content of spontaneous thought. Secondly, we propose that spontaneous retrieval is a privileged area to explore the question of functional independence between systems, because it provides direct access to the episodic system. We review the evidence for spontaneous thought in semantic dementia, which suggests that episodic and semantic systems are functionally independent. We acknowledge the scarcity of evidence and suggest that future studies examine the contents of spontaneous thought descriptions and their neural correlates to test the functional relationship and inform the interaction between episodic and semantic systems.

Memories for third-person experiences in immersive virtual reality.

We typically experience the world from a first-person perspective (1PP) but can sometimes experience events from a third-person perspective (3PP) much as an observer might see us. Little is known about how visual perspective influences the formation of memories for events. We developed an immersive virtual reality paradigm to examine how visual perspective during encoding influences memories. Across two studies, participants explored immersive virtual environments from first-person and third-person avatar perspectives while wearing an Oculus Rift headset. Memory was tested immediately (Study One and Study Two) and following a one-week delay (Study Two). We assessed the accuracy of visual memory using cued recall questions and spatial memory by asking participants to draw maps of the layout of each environment (Study One and Study Two). Additional phenomenological ratings were included to assess visual perspective during remembering (Study Two). There were no differences in the accuracy of visual information across the two studies, but 3PP experiences were found to increase spatial memory accuracy due to their wider camera field of view when compared to 1PP experiences. Our results also demonstrate that 3PP experiences create 3PP memories, as reflected by an increase in subjective ratings of observer-like perspectives during remembering. In sum, visual perspective during memory formation influences the accuracy of spatial but not visual information, and the vantage point of memories during remembering.

The effects of aging and an episodic specificity induction on spontaneous task-unrelated thought.

When voluntarily describing their past or future, older adults typically show a reduction in episodic specificity (e.g., including fewer details reflecting a specific event, time and/or place). However, aging has less impact on other types of tasks that place minimal demands on strategic retrieval such as spontaneous thoughts. In the current study, we investigated age-related differences in the episodic specificity of spontaneous thoughts using experimenter-based coding of thought descriptions. Additionally, we tested whether an episodic specificity induction, which increases episodic detail during deliberate retrieval of events in young and older adults, has the same effect under spontaneous retrieval. Twenty-four younger and 24 healthy older adults performed two counterbalanced sessions including a video, the episodic specificity or control induction, and a vigilance task. In the episodic specificity induction, participants recalled the details of the video while in the control they solved math exercises. The impact of this manipulation on the episodic specificity of spontaneous thoughts was assessed in the subsequent vigilance task, in which participants were randomly stopped to describe their thoughts and classify them as deliberate/spontaneous. We found no differences in episodic specificity between age groups in spontaneous thoughts, supporting the prediction that automatic retrieval attenuates the episodic specificity decrease in aging. The lack of age differences was present regardless of the induction, showing no interactions. For the induction, we also found no main effect, indicating that automatic retrieval bypasses event construction and accesses pre-stored events. Overall, our evidence suggests that spontaneous retrieval is a promising strategy to support episodic specificity in aging.

How visual perspective influences the spatiotemporal dynamics of autobiographical memory retrieval.

Visual perspective, recalling events from one's own eyes or one of several possible observer viewpoints, is a fundamental aspect of AM. Yet, exactly how visual perspective influences the functional mechanisms supporting retrieval is unclear. Here we used a multivariate analysis to characterize the spatiotemporal dynamics of networks supporting AM retrieval from multiple typical and atypical visual perspectives. Both own eyes and observer perspectives engaged an AM retrieval network (i.e., hippocampus, anterior and posterior midline, and lateral frontal and posterior cortices) that peaked during later retrieval periods, but was recruited less strongly for observer perspectives. Functional connectivity analyses with an anterior hippocampal seed revealed that visual perspective also affected the strength and timing of neural recruitment. There was stronger hippocampal connectivity with a posterior medial network during the initial retrieval of AMs from atypical observer perspectives and stronger within-MTL and ventromedial prefrontal cortex connectivity during later retrieval periods from own eyes perspectives, suggesting that visual perspective is an important factor in understanding how neocortical systems guide memory retrieval. Our findings demonstrate that adopting own eyes and observer perspectives during AM retrieval is correlated with distinct patterns of hippocampal-neocortical interactions associated with differential recruitment of the AM retrieval network during later retrieval periods, thereby supporting the central role of visual perspective in reconstructing the personal past.

Classification of general and personal semantic details in the Autobiographical Interview.

The Autobiographical Interview (AI) separates internal (episodic) and external (non-episodic) details from transcribed protocols using an exhaustive and reliable scoring system. While the details comprising the internal composite are centered on elements of episodic memory, external details are more heterogeneous as they are meant to capture a variety of non-episodic utterances: general semantics, different types of personal semantics details, metacognitive statements, repetitions, and details about off topic events. Elevated external details are consistently observed in aging and in neurodegenerative diseases. In the present study, we augmented the AI scoring system to differentiate subtypes of external details to test whether the elevation of these details in aging and in frontotemporal lobar degeneration (including mixed frontotemporal/semantic dementia [FTD/SD] and progressive non-fluent aphasia [PNFA]) would be specific to general and personal semantics or would concern all subtypes. Specifically, we separated general semantic details from personal semantic details (including autobiographical facts, self-knowledge, and repeated events). With aging, external detail elevation was observed for general and personal semantic details but not for other types of external details. In frontotemporal lobar degeneration, patients with FTD/SD (but not PNFA) generated an excess of personal semantic details but not general semantic details. The increase in personal but not general semantic details in FTD/SD is consistent with prevalent impairment of general semantic memory in SD, and with the personalization of concepts in this condition. Under standard AI instructions, external details were intended to capture off-topic utterances and were not intended as a direct measure of semantic abilities. Future investigations concerned with semantic processing in aging and in dementia could modify standard instructions of the AI to directly probe semantic content.

Differential contribution of anterior and posterior midline regions during mental simulation of counterfactual and perspective shifts in autobiographical memories.

Retrieving autobiographical memories induces a natural tendency to mentally simulate alternate versions of past events, either by reconstructing the perceptual details of the originally experienced perspective or the conceptual information of what actually occurred. Here we examined whether the episodic system recruited during imaginative experiences functionally dissociates depending on the nature of this reconstruction. Using fMRI, we evaluated differential patterns of neural activity and hippocampal connectivity when twenty-nine participants naturally recalled past negative events, shifted visual perspective, or imagined better or worse outcomes than what actually occurred. We found that counterfactual thoughts were distinguished by neural recruitment in dorsomedial prefrontal cortex, whereas shifts in visual perspective were uniquely supported by the precuneus. Additionally, connectivity with the anterior hippocampus changed depending upon the mental simulation that was performed - with enhanced hippocampal connectivity with medial prefrontal cortex for counterfactual simulations and precuneus for shifted visual perspectives. Together, our findings provide a novel assessment of differences between these common methods of mental simulation and a more detailed account for the neural network underlying episodic retrieval and reconstruction.

Reduction of the Self-Reference Effect in Younger and Older Adults.

Relating information to the self improves memory. However, this self-reference effect (SRE) is typically studied through explicit self-judgments on individual trials. The current study assessed whether a self-referential mode of thought, induced through a writing task, also induced an SRE on a later task. The study also tested the effects of aging on the SRE, given that a long-lasting mnemonic strategy may be especially relevant for this group. Ninety-two younger adults and 60 older adults were assigned to different writing conditions and then completed an unrelated SRE task. Across younger and older adults, the classic SRE effect was observed in the narrative writing condition, reduced in the semantic self-reference condition, and further reduced in the episodic self-reference condition. These results support the induction of a self-referential mode of thought, but this mode does not enhance memory. The classic SRE effect can be reduced after thinking about the self by reflecting on autobiographical memories. Results argue for a single shared self-referential mechanism that can be accessed through self-focused writing or the classic SRE task.

Meta-analysis of aging effects in mind wandering: Methodological and sociodemographic factors.

Our attention frequently shifts from ongoing tasks to internal content such that we find ourselves mind wandering (MW). Recent research has revealed that increasing age in adulthood is associated with a decrease in the frequency of MW, but the factors that contribute to this age-related effect are unclear. Thus, in the present study we conducted a meta-analysis of age differences in MW that aimed to analyze (a) the size and consistency of the age-related decrease in MW frequency, and (b) the moderating impact of methodological and sociodemographic factors. We analyzed studies comparing MW frequency in healthy younger and older groups and found a large effect in older adults. The age-related decrease in MW was more pronounced for probe compared to self-caught procedures, when task-related interfering thoughts were measured separately, when visual masks were presented, as the proportion of targets increased, and as older participants and fewer women were included in older adult groups. In discussing the theoretical and practical implications of these findings, we highlight the role of motivation and response options and provide recommendations for future research. These included emphasizing the need for open-ended methods in order to avoid bias due to MW instructions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Inducing spontaneous future thoughts in younger and older adults by priming future-oriented personal goals.

In the past 15 years, the study of spontaneous thoughts (i.e., thoughts coming to mind without intention and effort) has received increased attention. Spontaneous future thoughts (SFTs) are particularly important (e.g., in planning), yet difficult to study with regard to age differences. Two main problems arise: (1) lab tasks including word-cues induce more past than future thoughts; (2) younger adults report more spontaneous thoughts than older adults. To improve the elicitation of SFTs, we developed a future-oriented goal-related priming procedure and analyzed the extension of the goal-related priming effect in SFTs to older adults, to examine whether age-related changes in personal goals compromise the elicitation of SFTs. We also controlled for methodological factors that could influence age groups differently (including demand, retrospection, meta-awareness and instruction bias). Twenty-seven younger and 27 older adults performed a low-demand vigilance task including word-cues and were periodically stopped to describe their thoughts. The vigilance task was divided into two parts and, between them, participants performed a future-oriented goal-related priming task. An additional group of 27 younger participants performed the same procedure with a control task based on word counting. We found a significant increase in SFTs after priming in both age groups, but not in the control group, indicating that the priming manipulation was effective. This result suggests that age-related changes in personal goals do not disrupt the relation between personal goals and SFT frequency. The similar pattern of overall spontaneous thought in both age groups is also discussed considering methodological factors.

How thinking about what could have been affects how we feel about what was.

Episodic counterfactual thoughts (CFT) and autobiographical memories (AM) involve the reactivation and recombination of episodic memory components into mental simulations. Upon reactivation, memories become labile and prone to modification. Thus, reactivating AM in the context of mentally generating CFT may provide an opportunity for editing processes to modify the content of the original memory. To examine this idea, this paper reports the results of two studies that investigated the effect of reactivating negative and positive AM in the context of either imagining a better (i.e. upward CFT) or a worse (i.e. downward CFT) alternative to an experienced event, as opposed to attentively retrieving the memory without mental modification (i.e. remembering) or no reactivation. Our results suggest that attentive remembering was the best strategy to both reduce the negative affect associated with negative AM, and to prevent the decay of positive affect associated with positive AM. In addition, reactivating positive, but not negative, AM with or without CFT modification reduces the perceived arousal of the original memory over time. Finally, reactivating negative AM in a downward CFT or an attentive remembering condition increases the perceived detail of the original memory over time.

Remembering and imagining alternative versions of the personal past.

Although autobiographical memory and episodic simulations recruit similar core brain regions, episodic simulations engage additional neural recruitment in the frontoparietal control network due to greater demands on constructive processes. However, previous functional neuroimaging studies showing differences in remembering and episodic simulation have focused on veridical retrieval of past experiences, and thus have not fully considered how retrieving the past in different ways from how it was originally experienced may also place similar demands on constructive processes. Here we examined how alternative versions of the past are constructed when adopting different egocentric perspectives during autobiographical memory retrieval compared to simulating hypothetical events from the personal past that could have occurred, or episodic counterfactual thinking. Participants were asked to generate titles for specific autobiographical memories from the last five years, and then, during functional magnetic resonance (fMRI) scanning, were asked to repeatedly retrieve autobiographical memories or imagine counterfactual events cued by the titles. We used an fMRI adaptation paradigm in order to isolate neural regions that were sensitive to adopting alternative egocentric perspectives and counterfactual simulations of the personal past. The fMRI results revealed that voxels within left posterior inferior parietal and ventrolateral frontal cortices were sensitive to novel visual perspectives and counterfactual simulations. Our findings suggest that the neural regions supporting remembering become more similar to those underlying episodic simulation when we adopt alternative egocentric perspectives of the veridical past.

Shifting visual perspective during memory retrieval reduces the accuracy of subsequent memories.

Memories for events can be retrieved from visual perspectives that were never experienced, reflecting the dynamic and reconstructive nature of memories. Characteristics of memories can be altered when shifting from an own eyes perspective, the way most events are initially experienced, to an observer perspective, in which one sees oneself in the memory. Moreover, recent evidence has linked these retrieval-related effects of visual perspective to subsequent changes in memories. Here we examine how shifting visual perspective influences the accuracy of subsequent memories for complex events encoded in the lab. Participants performed a series of mini-events that were experienced from their own eyes, and were later asked to retrieve memories for these events while maintaining the own eyes perspective or shifting to an alternative observer perspective. We then examined how shifting perspective during retrieval modified memories by influencing the accuracy of recall on a final memory test. Across two experiments, we found that shifting visual perspective reduced the accuracy of subsequent memories and that reductions in vividness when shifting visual perspective during retrieval predicted these changes in the accuracy of memories. Our findings suggest that shifting from an own eyes to an observer perspective influences the accuracy of long-term memories.

Shifting visual perspective during retrieval shapes autobiographical memories.

The dynamic and flexible nature of memories is evident in our ability to adopt multiple visual perspectives. Although autobiographical memories are typically encoded from the visual perspective of our own eyes they can be retrieved from the perspective of an observer looking at our self. Here, we examined the neural mechanisms of shifting visual perspective during long-term memory retrieval and its influence on online and subsequent memories using functional magnetic resonance imaging (fMRI). Participants generated specific autobiographical memories from the last five years and rated their visual perspective. In a separate fMRI session, they were asked to retrieve the memories across three repetitions while maintaining the same visual perspective as their initial rating or by shifting to an alternative perspective. Visual perspective shifting during autobiographical memory retrieval was supported by a linear decrease in neural recruitment across repetitions in the posterior parietal cortices. Additional analyses revealed that the precuneus, in particular, contributed to both online and subsequent changes in the phenomenology of memories. Our findings show that flexibly shifting egocentric perspective during autobiographical memory retrieval is supported by the precuneus, and suggest that this manipulation of mental imagery during retrieval has consequences for how memories are retrieved and later remembered.

Emotional evaluation and memory in behavioral variant frontotemporal dementia.

Behavioral variant frontotemporal dementia (bvFTD) affects emotional evaluation, but less is known regarding the patients' ability to remember emotional stimuli. Here, bvFTD patients and age-matched controls studied positive, negative, and neutral pictures followed by a recognition memory test. Compared to controls, bvFTD patients showed a reduction in emotional evaluation of negative scenes, but not of positive or neutral scenes. Additionally, the patients showed an overall reduction in recognition memory accuracy, due to impaired recollection in the face of relatively preserved familiarity. These results show that bvFTD reduces the emotional evaluation of negative scenes and impairs overall recognition memory accuracy and recollection.

Modifying memory for a museum tour in older adults: Reactivation-related updating that enhances and distorts memory is reduced in ageing.

Memory reactivation, the activation of a latent memory trace when we are reminded of a past experience, strengthens memory but can also contribute to distortions if new information present during reactivation is integrated with existing memory. In a previous study in young adults we found that the quality of memory reactivation, manipulated using the principle of encoding specificity and indexed by recollection ratings, modulated subsequent true and false memories for events experienced during a museum tour. Here in this study, we examined age-related changes in the quality of memory reactivation on subsequent memory. Memories of museum stops in young and older adults were reactivated and then immediately followed by the presentation of a novel lure photo from an alternate tour version (i.e., reactivation plus new information). There was an increase in subsequent true memories for reactivated targets and for subsequent false memories for lures that followed reactivated targets, when compared to baseline target and lure photos. However, the influence of reactivation on subsequent memories was reduced in older adults. These data reveal that ageing alters reactivation-related updating processes that allow memories to be strengthened and updated with new information, consequently reducing memory distortions in older adults compared to young adults.