Constructive Episodic Simulation Research Articles

A fragile effect: The influence of episodic memory on delay discounting.

Delay discounting occurs when a reward loses value as a function of delay. Episodic future thinking (EFT) reliably decreases delay discounting. EFT may share cognitive features with recalling episodic memories such as constructive episodic simulation. We therefore explored whether recalling episodic memories also reduces delay discounting. In Experiment 1, participants wrote about episodic memories and recalled those memories before completing a delay discounting task. Episodic memories reduced delay discounting according to one commonly used delay discounting measure (area under the curve) but not another (using the hyperbolic model). Experiment 2 compared the effects of general and episodic memories. Neither general nor episodic memories significantly decreased delay discounting compared with a control "counting" condition, but episodic memories reduced delay discounting compared with general memories under some conditions. In Experiment 3, episodic memories did not decrease delay discounting compared with three other control conditions while EFT did. Experiment 3 therefore found that thinking must be both episodic and future orientated to reduce delay discounting. Together, these results suggest that episodic thinking is not sufficient to reliably decrease delay discounting, rather, features unique to episodic future thinking are required. Episodic memory might reduce delay discounting in some contexts, but this effect is small and fragile.

Prática da Lembrança: Perspectivas Teóricas e a Hipótese do Aprendizado Baseado na Simulação Construtiva

A large number of recent studies demonstrates that the act of remembering previously studied contents is an eff ective strategy to promote the long-term retention of these contents. This strategy, known as “retrieval practice”, has been viewed as an eff ective strategy to improve learning in diff erent educational settings. However, there is still no consensus about which cognitive mechanisms produce its benefi ts. The present work is a narrative review which covers the main theories about the cognitive mechanisms underlying the benefi ts of retrieval practice. After critically reviewing such theories, we propose a new theoretical account, which is based on cognitive neuroscience fi ndings and intends to resolve inconsistencies found in previous theories. This new hypothesis assumes that the benefi t of retrieval practice results from the engagement of constructive episodic simulations, which are sustained by neural structures of the default mode network. More importantly, while such episodic simulation processes can be engaged by memory tasks, such as retrieval practice, they can be also engaged by tasks involving semantic elaboration or imaginative processes. Consequently, the present hypothesis predicts that the benefi ts of retrieval practice can be reproduced by non-retrieval tasks, as long as they engage constructive episodic simulations. Keywords: Retrieval practice, constructive episodic simulation, memory, learning, cognition

How does tourism memory affect revisit decisions? The mediating role of episodic future thinking

Although scholars have explored how memorable tourism experiences affect tourists' behaviour, little research has considered the role of tourism memory from an autobiographical memory phenomenology perspective—particularly negative tourism memories. By combining the notion of mental time travel with the constructive episodic simulation hypothesis, this research proposes a theoretical framework describing the effects of positive and negative tourism memories on revisit intention through episodic future thinking. A questionnaire survey and two experiments jointly revealed that tourists' revisit intentions were stronger when memories of previous visits were positive. Episodic future thinking partly mediated the association between tourism memory valence and revisit intention. Moreover, positive external information could strengthen the effect of episodic future thinking on this intention. Results offer practical guidance on harnessing tourism memory to improve destinations' competitiveness.

Kinding memory: Commentary on Muhammad Ali Khalidi's Cognitive ontology

My commentary focuses on Khalidi's defense of episodic memory as a cognitive kind. His argument relies on merging two distinct accounts of episodic memory—the phenomenal and the etiological. I suggest that Khalidi's framework can be used to carve the contemporary memory literature differently. On this view, the phenomenal account supports constructive episodic simulation as a cognitive kind, the etiological account supports event memory as a cognitive kind, and episodic memory ceases to be. The question for Khalidi is, then, how to evaluate this alternative proposal—and more broadly how to adjudicate between competing and overlapping accounts of cognitive kinds.

Aphantasia: In search of a theory

Though researchers working on congenital aphantasia (henceforth “aphantasia”) agree that this condition involves an impairment in the ability to voluntarily generate visual imagery, disagreement looms large as to which other impairments are exhibited by aphantasic subjects. This article offers the first extensive review of studies on aphantasia, and proposes that aphantasic subjects exhibit a cluster of impairments. It puts forward a novel cognitive theory of aphantasia, building on the constructive episodic simulation hypothesis of memory and imagination. It argues that aphantasia is best explained as a malfunction of processes in the episodic system, and is therefore an episodic system condition.

Constructive episodic simulation in dreams.

Memories of the past help us adaptively respond to similar situations in the future. Originally described by Schacter & Addis in 2007, the “constructive episodic simulation” hypothesis proposes that waking thought combines fragments of various past episodes into imagined simulations of events that may occur in the future. This same framework may be useful for understanding the function of dreaming. N = 48 college students were asked to identify waking life sources for a total of N = 469 dreams. Participants frequently traced dreams to at least one past or future episodic source (53.5% and 25.7% of dreams, respectively). Individual dreams were very often traced to multiple waking sources (43.9% of all dreams with content), with fragments of past memory incorporated into scenarios that anticipated future events. Waking-life dream sources are described in terms of their phenomenology and distribution across time and sleep stage, providing new evidence that dreams not only reflect the past, but also utilize memory in simulating potential futures.

Schema-related eye movements support episodic simulation

Recent work indicates that eye movements support the retrieval of episodic memories by reactivating the spatiotemporal context in which they were encoded. Although similar mechanisms have been thought to support simulation of future episodes, there is currently no evidence favoring this proposal. In the present study, we investigated the role of eye movements in episodic simulation by comparing the gaze patterns of individual participants imagining future scene and event scenarios to across-participant gaze templates for those same scenarios, reflecting their shared features (i.e., schemas). Our results provide novel evidence that eye movements during episodic simulation in the face of distracting visual noise are (1) schema-specific and (2) predictive of simulation success. Together, these findings suggest that eye movements support episodic simulation via reinstatement of scene and event schemas, and more broadly, that interactions between the memory and oculomotor effector systems may underlie critical cognitive processes including constructive episodic simulation.

Mental Time Travel in Post-Traumatic Stress Disorder: Current Gaps and Future Directions.

Mental Time Travel in Post-Traumatic Stress Disorder: Current Gaps and Future Directions.

Mental Time Travel? A Neurocognitive Model of Event Simulation

Mental time travel (MTT) is defined as projecting the self into the past and the future. Despite growing evidence of the similarities of remembering past and imagining future events, dominant theories conceive of these as distinct capacities. I propose that memory and imagination are fundamentally the same process – constructive episodic simulation – and demonstrate that the ‘simulation system’ meets the three criteria of a neurocognitive system. Irrespective of whether one is remembering or imagining, the simulation system: (1) acts on the same information, drawing on elements of experience ranging from fine-grained perceptual details to coarser-grained conceptual information and schemas about the world; (2) is governed by the same rules of operation, including associative processes that facilitate construction of a schematic scaffold, the event representation itself, and the dynamic interplay between the two (cf. predictive coding); and (3) is subserved by the same brain system. I also propose that by forming associations between schemas, the simulation system constructs multi-dimensional cognitive spaces, within which any given simulation is mapped by the hippocampus. Finally, I suggest that simulation is a general capacity that underpins other domains of cognition, such as the perception of ongoing experience. This proposal has some important implications for the construct of ‘MTT’, suggesting that ‘time’ and ‘travel’ may not be defining, or even essential, features. Rather, it is the ‘mental’ rendering of experience that is the most fundamental function of this domain-general simulation system enabling humans to re-experience the past, pre-experience the future, and also comprehend the complexities of the present.

Improving Mental Time Travel in Schizophrenia: Do Remembering the Past and Imagining the Future Make a Difference?

Mental time travel (MTT) refers to the ability to project oneself into the past to re-experience past events or into the future to pre-experience future events. This ability plays an important role in daily life. MTT is severely impaired in patients with schizophrenia (SZ). Studies have shown that life review therapy (LRT, remembering the past) could improve MTT ability in SZ. However, whether training to imagine the future can improve MTT and whether the combined training to remember the past and imagine the future can improve MTT to a larger degree remain unknown. The present study aimed to examine these issues. Eighty patients with SZ were randomly assigned to the remembering training group (SZ-re-training), future imagining training group (SZ-im-training), combined remembering and future imagining training group (SZ-re-im-training), or control group (SZ-control). All SZ-training groups received 8 training sessions over four weeks. MTT ability, emotion, life satisfaction, cognitive functions and clinical symptoms were assessed before and after training. Twenty-one matched healthy controls were also recruited and completed the baseline assessment. The results showed that the specificity of MTT in all SZ-training groups was higher than that in the SZ-control group after training; there was no significant difference among the three training groups. The SZ-training group also showed significant improvement in clinical symptoms and other cognitive functions, such as verbal and visual memory, whereas the SZ-control group did not. These results suggest that all three training methods improved the MTT ability of SZ patients to a similar degree and support the constructive episodic simulation hypothesis. The trial registration number of this study is ChiCTR-INR-17014096 and the date of registration is Dec 22, 2017.

How does the non-conscious become conscious?

In this My Word, Joseph LeDoux describes how his work as a graduate student got him interested in human consciousness. Although he has not studied this topic since 1970s, he never stopped thinking and writing about it during his four-decade career exploring how non-conscious processes involving the amygdala detect and respond to danger. Here, he tells us what is on his mind about consciousness these days.

Evolutionary shifts dramatically reorganized the human hippocampal complex.

The hippocampal complex (HC) is central to long-term memory storage and retrieval as well as spatial navigation across many species. Notably, humans appear to have greatly enhanced and possibly unique HC-mediated capacities such as constructive episodic simulation. Key studies have shown that the human HC is disproportionately large amongst hominoids, but much remains unknown at the levels of substructural evolutionary reorganization and ecological selection. Here, we calculated relative sizes of 12 HC subregions in a diverse sample of 44 primate species. We then used a Bayesian phylogenetic method, selective regime analysis, to identify 27 separate evolutionary shifts in HC organization across 65 million years of primate evolution. Additionally, a series of multivariate phylogenetic regressions using HC-related ecological variables as predictors (Diet Breadth, Population Density, Group Size, Home Range Size, and Residual Home Range) revealed that relative fascia dentata and CA1 size were both significantly predicted by species' home range size (after correcting for body size). However, perhaps the most notable finding of this study was that the shifts in HC size and subregional organization in the human lineage were the largest seen in all of primate evolution, rendering modern humans with a HC that is a clear outlier amongst all nonhuman primates investigated here. Given the extensive literature confirming the relationship between HC organization and function, these selective shifts are likely to have played a significant role in the emergence of human-specific capacities, such as constructive episodic simulation.

Reinstatement of Event Details during Episodic Simulation in the Hippocampus.

According to the constructive episodic simulation hypothesis, episodic simulation (i.e., imagining specific novel future episodes) draws on some of the same neurocognitive processes that support episodic memory (i.e., recalling specific past episodes). Episodic retrieval supports the ability to simulate future experiences by providing access to episodic details (e.g., the people and locations that comprise memories) that can be recombined in new ways. In the current functional neuroimaging study, we test this hypothesis by examining whether the hippocampus, a region implicated in the reinstatement of episodic information during memory, supports reinstatement of episodic information during simulation. Employing a multivoxel pattern similarity analysis, we interrogated the similarity between hippocampal neural patterns during memory and simulation at the level of individual event details. Our findings indicate that the hippocampus supports the reinstatement of detail-specific information from episodic memory during simulation, with the level of reinstatement contributing to the subjective experience of simulated details.

Remembering the past and imagining the future: attachment effects on production of episodic details in close relationships

ABSTRACTAttachment theories and studies have shown that Internal Working Models (IWMs) can impact autobiographical memory and future-oriented information processing relevant to close relationships. According to the constructive episodic simulation hypothesis (CESH), both remembering the past and imagining the future rely on episodic memory. We hypothesised that one way IWMs may bridge past experiences and future adaptations is via episodic memory. The present study investigated the association between attachment and episodic specificity in attachment-relevant and attachment-irrelevant memory and imagination among young and older adults. We measured the attachment style of 37 young adults and 40 older adults, and then asked them to remember or imagine attachment-relevant and attachment-irrelevant events. Participants’ narratives were coded for internal details (i.e., episodic) and external details (e.g., semantic, repetitions). The results showed that across age group, secure individuals generated more internal details and fewer external details in attachment-relevant tasks compared to attachment-irrelevant tasks; these differences were not observed in insecure individuals. These findings support the CESH and provide a new perspective to understand the function of IWMs.

Constructive episodic simulation, flexible recombination, and memory errors.

According to Mahr & Csibra (M&C), the view that the constructive nature of episodic memory is related to its role in simulating future events has difficulty explaining why memory is often accurate. We hold this view, but disagree with their conclusion. Here we consider ideas and evidence regarding flexible recombination processes in episodic retrieval that accommodate both accuracy and distortion.

Remembering the past and imagining the future: Identifying and enhancing the contribution of episodic memory

Recent studies have shown that imagining or simulating future events relies on many of the same cognitive and neural processes as remembering past events. According to the constructive episodic simulation hypothesis (Schacter and Addis, 2007), such overlap indicates that both remembered past and imagined future events rely heavily on episodic memory: future simulations are built on retrieved details of specific past experiences that are recombined into novel events. An alternative possibility is that commonalities between remembering and imagining reflect the influence of more general, non-episodic factors such as narrative style or communicative goals that shape the expression of both memory and imagination. We consider recent studies that distinguish the contributions of episodic and non-episodic processes in remembering the past and imagining the future by using an episodic specificity induction - brief training in recollecting the details of a past experience - and also extend this approach to the domains of problem solving and creative thinking. We conclude by suggesting that the specificity induction may target a process of scene construction that contributes to episodic memory as well as to imagination, problem solving, and creative thinking.

Remembering the past and imagining the future: Selective effects of an episodic specificity induction on detail generation

According to the constructive episodic simulation hypothesis, remembering past experiences and imagining future experiences both rely heavily on episodic memory. However, recent research indicates that nonepisodic processes such as descriptive ability also influence memory and imagination. We recently found that an episodic specificity induction--brief training in recollecting details of past experiences--enhanced detail generation on memory and imagination tasks but not a picture description task and thereby concluded that the induction can dissociate episodic processes involved in remembering the past and imagining the future from those nonepisodic processes involved in description. To evaluate the generality of our previous findings and to examine the role of generative search in producing those findings, we modified our paradigm so that word cues replaced picture cues, and a word comparison task that requires generation of sentences and word definitions replaced picture description. Young adult participants received either a specificity induction or one of two control inductions before completing the memory, imagination, and word comparison tasks. Replicating and extending our previous work, we found that the specificity induction increased detail generation in memory and imagination without having an effect on word comparison. The induction's selective effect on memory and imagination stemmed from an increase in internal (i.e., on-topic and episodic) details and had no effect on external (e.g., off-topic or semantic) details. The results point to the efficacy of the specificity induction for isolating episodic processes involved in remembering the past and imagining the future even when a nonepisodic task requires generative search.

Visual perspective in remembering and episodic future thought.

According to the constructive episodic simulation hypothesis, remembering and episodic future thinking are supported by a common set of constructive processes. In the present study, we directly addressed this assertion in the context of third-person perspectives that arise during remembering and episodic future thought. Specifically, we examined the frequency with which participants remembered past events or imagined future events from third-person perspectives. We also examined the different viewpoints from which third-person perspective events were remembered or imagined. Although future events were somewhat more likely to be imagined from a third-person perspective, the spatial viewpoint distributions of third-person perspectives characterizing remembered and imagined events were highly similar. These results suggest that a similar constructive mechanism may be at work when people remember events from a perspective that could not have been experienced in the past and when they imagine events from a perspective that could not be experienced in the future. The findings are discussed in terms of their consistency with--and as extensions of--the constructive episodic simulation hypothesis.

Constructive episodic simulation: Dissociable effects of a specificity induction on remembering, imagining, and describing in young and older adults.

According to the constructive episodic simulation hypothesis (Schacter & Addis, 2007), both remembered past and imagined future events rely heavily on episodic memory. An alternative hypothesis is that observed similarities between remembering and imagining reflect the influence of broader factors such as descriptive ability, narrative style, or inhibitory control. We attempted to distinguish between these 2 hypotheses by examining the impact of an episodic specificity induction on memory, imagination, and picture description in young and older adults. In Experiment 1, participants received the specificity induction or a control induction prior to the memory, imagination, and description tasks. Older adults provided fewer internal (i.e., episodic) and more external (i.e., semantic) details than young adults across the 3 tasks irrespective of induction. Critically, however, the specificity induction selectively increased internal but not external details for memory and imagination in both age groups compared with the control induction. By contrast, the induction did not affect internal (or external) details for picture description. Experiment 2 replicated these results in young adults using a different control induction. Our findings point to a dissociation between episodic processes involved in memory and imagination and nonepisodic processes involved in picture description.

Thinking about the future early in life: The role of relational memory

The constructive episodic simulation hypothesis suggests that we imagine possible future events by flexibly recombining details of past experiences to produce novel scenarios. Here we tested this hypothesis by determining whether episodic future thinking is related to relational memory ability during the preschool years. Children (3- to 5-year-olds) were asked to remember a past event and imagine a possible future event using an adapted version of the recombination paradigm. Relational learning and inference were assessed using a task adapted from the neuroimaging literature. The results show that preschoolers were able to describe both past and possible future events; however, they produced more specific episodic details in relation to past events relative to future events. Episodic future thinking performance was correlated with performance on the relational inference task, consistent with the idea that the ability to flexibly recombine relational knowledge is critical in episodic future thinking.