Episodic simulation of future events: concepts, data, and applications

Neurocognitive and Information Processing Biases in Posttraumatic Stress Disorder

PURPOSE OF REVIEW

We review recent research addressing neurocognitive and information processing abnormalities in posttraumatic stress disorder (PTSD), including studies informing direction of causality. We additionally consider neurocognition in the context of co-morbid mild traumatic brain injury (TBI) and psychosocial treatments for PTSD.

RECENT FINDINGS

Learning, memory, attention, inhibitory functions, and information processing biases frequently accompany PTSD, reflecting potential bi-directional relationships with PTSD. Although mild TBI is associated with increased risk of PTSD development and maintenance, TBI does not typically contribute significantly to sustained neurocognitive deficits in individuals with PTSD. Whereas better learning and memory is associated with mildly enhanced response to psychosocial interventions, such interventions may also improve neurocognitive performance and can be effectively provided to patients with TBI history. PTSD is associated with cognitive abnormalities in processing both emotionally relevant and emotionally neutral information and, although mild, may underlie some PTSD symptom expression.

Facets of Subjective Health Horizons Are Differentially Linked to Brain Volume

Abstract. An active lifestyle including physical exercise and novelty processing is considered to promote brain health. Also, subjective future time perspectives (FTP) are known to shape motivation and goal-directed behavior, with links to objective health, well-being, and cognition. Nevertheless, the links between subjective FTP and brain physiology are largely unknown. We report data from 326 healthy older adults who completed the Subjective Health Horizon Questionnaire (SHH-Q) and structural magnetic resonance imaging (MRI). Voxel-based morphometry analyses revealed associations between (1) the SHH-Q Novelty factor and brain regions of the episodic memory network, and (2) the SHH-Q Body factor and regions contributing to the cortical representation of bodily states. Longitudinal and experimental data are needed to better understand the etiology of these links.

Generative Predictive Codes by Multiplexed Hippocampal Neuronal Tuplets

Rapid internal representations are continuously formed based on single experiential episodes in space and time, but the neuronal ensemble mechanisms enabling rapid encoding without constraining the capacity for multiple distinct representations are unknown. We developed a probabilistic statistical model of hippocampal spontaneous sequential activity and revealed existence of an internal model of generative predictive codes for the regularities of multiple future novel spatial sequences. During navigation, the inferred difference between external stimuli and the internal model was encoded by emergence of intrinsic-unlikely, novel functional connections, which updated the model by preferentially potentiating post-experience. This internal model and these predictive codes depended on neuronal organization into inferred modules of short, high-repeat sequential neuronal "tuplets" operating as "neuro-codons." We propose that flexible multiplexing of neuronal tuplets into repertoires of extended sequences vastly expands the capacity of hippocampal predictive codes, which could initiate top-down hierarchical cortical loops for spatial and mental navigation and rapid learning.

Metastable neural dynamics in Alzheimer's disease are disrupted by lesions to the structural connectome

Current theory suggests brain regions interact to reconcile the competing demands of integration and segregation by leveraging metastable dynamics. An emerging consensus recognises the importance of metastability in healthy neural dynamics where the transition between network states over time is dependent upon the structural connectivity between brain regions. In Alzheimer's disease (AD) - the most common form of dementia - these couplings are progressively weakened, metastability of neural dynamics are reduced and cognitive ability is impaired. Accordingly, we use a joint empirical and computational approach to reveal how behaviourally relevant changes in neural metastability are contingent on the structural integrity of the anatomical connectome. We estimate the metastability of fMRI BOLD signal in subjects from across the AD spectrum and in healthy controls and demonstrate the dissociable effects of structural disconnection on synchrony versus metastability. In addition, we reveal the critical role of metastability in general cognition by demonstrating the link between an individuals cognitive performance and their metastable neural dynamic. Finally, using whole-brain computer modelling, we demonstrate how a healthy neural dynamic is conditioned upon the topological integrity of the structural connectome. Overall, the results of our joint computational and empirical analysis suggest an important causal relationship between metastable neural dynamics, cognition, and the structural efficiency of the anatomical connectome.

The dynamic interplay between acute psychosocial stress, emotion and autobiographical memory

Although acute psychosocial stress can impact autobiographical memory retrieval, the nature of this effect is not entirely clear. One reason for this ambiguity is because stress can have opposing effects on the different stages of autobiographical memory retrieval. We addressed this issue by testing how acute stress affects three stages of the autobiographical memory retrieval - accessing, recollecting and reconsolidating a memory. We also investigate the influence of emotion valence on this effect. In a between-subjects design, participants were first exposed to an acute psychosocial stressor or a control task. Next, the participants were shown positive, negative or neutral retrieval cues and asked to access and describe autobiographical memories. After a three to four day delay, participants returned for a second session in which they described these autobiographical memories. During initial retrieval, stressed participants were slower to access memories than were control participants; moreover, cortisol levels were positively associated with response times to access positively-cued memories. There were no effects of stress on the amount of details used to describe memories during initial retrieval, but stress did influence memory detail during session two. During session two, stressed participants recovered significantly more details, particularly emotional ones, from the remembered events than control participants. Our results indicate that the presence of stress impairs the ability to access consolidated autobiographical memories; moreover, although stress has no effect on memory recollection, stress alters how recollected experiences are reconsolidated back into memory traces.

A brief period of eyes-closed rest enhances motor skill consolidation

Post-training sleep benefits both declarative and procedural memory consolidation. However, recent research suggests that eyes-closed waking rest may provide a similar benefit. Brokaw et al. (2016), for example, recently demonstrated that verbal declarative memory improved more following a 15 min period of waking rest, in comparison to 15 min of active wake. Here, we used the same procedures to test whether procedural memory similarly benefits from waking rest. Participants were trained on the Motor Sequence Task (MST), followed by a 15 min retention interval during which they either rested with their eyes closed or completed a distractor task. Rest significantly enhanced MST performance, mirroring the effect observed in Brokaw et al. (2016) and demonstrating that waking rest benefits the early stages of procedural memory. An additional group of participants tested 4 h later displayed no effect of rest. Overall, these results suggest that the early MST performance "boost" described in prior studies may depend on post-learning state.

Semantic future thinking and executive functions at age 4: The moderating role of frontal brain electrical activity

Previous studies provide conflicting results regarding the relation between future thinking and executive functioning during early childhood. Furthermore, little is known of the neural mechanisms involved in future thinking during early childhood. We examined the moderating role of frontal electroencephalogram (EEG) activity on the relation between executive functioning and semantic future thinking performance in a sample of 4-year-old children. Our results suggest that frontal EEG moderates the relation between executive functioning and semantic future thinking performance, but only for medium to high levels of frontal EEG power values. These results provide emerging evidence regarding the role of both executive functioning and frontal brain electrical activity on semantic future thinking in 4-year-olds.

Enhancing memory and imagination improves problem solving among individuals with depression

Recent work has revealed links between memory, imagination, and problem solving, and suggests that increasing access to detailed memories can lead to improved imagination and problem-solving performance. Depression is often associated with overgeneral memory and imagination, along with problem-solving deficits. In this study, we tested the hypothesis that an interview designed to elicit detailed recollections would enhance imagination and problem solving among both depressed and nondepressed participants. In a within-subjects design, participants completed a control interview or an episodic specificity induction prior to completing memory, imagination, and problem-solving tasks. Results revealed that compared to the control interview, the episodic specificity induction fostered increased detail generation in memory and imagination and more relevant steps on the problem-solving task among depressed and nondepressed participants. This study builds on previous work by demonstrating that a brief interview can enhance problem solving among individuals with depression and supports the notion that episodic memory plays a key role in problem solving. It should be noted, however, that the results of the interview are relatively short-lived.

Positivity bias in past and future episodic thinking: Relationship with anxiety, depression, and retrieval-induced forgetting

Positivity biases in autobiographical memory and episodic future thinking are considered important in mental wellbeing and are reduced in anxiety and depression. The inhibitory processes underlying retrieval-induced forgetting (RIF) have been proposed to contribute to these biases. This investigation found reduced positivity in past and future thinking to be associated with reduced memory specificity alongside greater levels of anxiety, depression, and rumination. Most notably, however, RIF was found to significantly predict memory valence. This indicates that RIF may be important in maintaining such biases, facilitating the forgetting of negative memories when a positive item is actively retrieved.

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

Attachment 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.

Delay of Gratification, Delay Discounting and their Associations with Age, Episodic Future Thinking, and Future Time Perspective

The delay of gratification (DoG) in children is widely investigated with an experimental procedure originally called the “marshmallow test,” whereas the studies on self-regulation (SR) in adolescents and adults usually use self-report questionnaires. Delay discounting (DD) measures simplify the DoG procedure and focus on monetary rewards. The aim of this study was to investigate age differences in DoG and DD from childhood to old age using a test that is suitable for both children and adults. Furthermore, investigations were conducted on the association between DoG/DD and two future orientation constructs [future time perspective (FTP) and episodic future thinking (EFT)] as well as age differences in these constructs. Participants from five age groups (9–14, 18–25, 35–55, 65–80, 80+) participated in the study (N = 96). While we found no age difference for DoG, DD was the lowest [i.e., self-control (SC) was the highest] in young/middle adults; however, it was the highest (i.e., SC was the lowest) in children and old/oldest adults. Furthermore, we found significant age differences for DD and FTP. As predicted, there were strong correlations between DoG and FTP and between DD and FTP, but not between DoG/DD and EFT. These results indicate that age differences in SR vary across the measures used. Individuals who generally think and act in a future-oriented manner have a stronger ability to delay gratification.

Modeling the Predictive Social Mind

The social mind is tailored to the problem of predicting the mental states and actions of other people. However, social cognition researchers have only scratched the surface of the predictive social mind. We discuss here a new framework for explaining how people organize social knowledge and use it for social prediction. Specifically, we propose a multilayered framework of social cognition in which two hidden layers - the mental states and traits of others - support predictions about the observable layer - the actions of others. A parsimonious set of psychological dimensions structures each layer, and proximity within and across layers guides social prediction. This simple framework formalizes longstanding intuitions from social cognition, and in doing so offers a generative model for deriving new hypotheses about predictive social cognition.

Non-Dependent and Dependent Daily Cannabis Users Differ in Mental Health but Not Prospective Memory Ability

Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM) for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18) or non-dependent (n = 18), and compared them with non-using controls (n = 18). The effect of future event simulation (FES) on PM performance was also examined. Participants were matched across groups on age, gender, and highest level of education. The virtual week (VW) was used to objectively assess PM abilities, both at baseline and following FES. Other measures used were: cannabis use variables, immediate and delayed prose recall, phonemic and category fluency, spot-the-word test (premorbid intelligence), Beck Depression Inventory, Beck Anxiety Inventory, and a measure of schizotypy (Oxford-Liverpool Inventory of Feelings and Experiences: unusual experiences subscale). No group differences were found in PM performance on the VW, and FES did not improve PM performance in any group. Dependent cannabis users scored higher on depression, anxiety, and schizotypy than both other groups with non-dependent cannabis users scoring at a similar level to controls. There were no group differences in alcohol use. Findings suggest that when carefully matched on baseline variables, and not differing in premorbid IQ or alcohol use, young, near-daily cannabis users do not differ from non-using controls in PM performance.

Stress-related cortisol responsivity modulates prospective memory

It is known that there is inter-individual variation in behavioural and physiological stress reactions to the same stressor. The present study aimed to examine the impact of cortisol responsivity on performance in a complex real life-like prospective memory (PM) paradigm by a re-analysis of data published previously, with a focus on the taxonomy of cognitive dimensions of PM. Twenty-one male subjects were stressed with the Socially Evaluated Cold Pressor Test (SECPT) before the planning of intentions. Another group of 20 males underwent a control procedure. Salivary cortisol was measured to assess the intensity of the biological stress response. Additionally, participants rated the subjective experience of stress on a 5-point rating scale. Stressed participants were post-hoc differentiated in high (n = 11) and low cortisol responders (n = 10). Cortisol niveau differed significantly between the two groups, whereas subjective stress ratings did not. PM performance of low cortisol responders was stable across time and the PM performance of controls declined. High cortisol responders showed a nominally weaker PM retrieval across the early trails and significantly improved only on the last trial. The data demonstrate for the first time that participants with a low cortisol responsivity may benefit from stress exposure before the planning phase of PM. PM performance of high cortisol responders shows a more inconsistent pattern, which may be interpreted in the sense of a recency effect in PM retrieval. Alternatively, high cortisol responses may have a deteriorating effect on PM retrieval, which disappeared on the last trials of the task as a result of the decrease of cortisol levels across time. Importantly, the data also demonstrate that the intensity of cortisol responses does not necessarily correspond to the intensity of the mental experience of stress.

Integration of Semantic and Episodic Memories

This paper describes the integration of semantic and episodic memory (EM) models and the benefits of such integration. Semantic memory (SM) is used as a foundation of knowledge and concept learning, and is needed for the operation of any cognitive system. EM retains personal experiences stored based on their significance-it is supported by the SM, and in return, it supports SM operations. Integrated declarative memories are critical for cognitive system development, yet very little research has been done to develop their computational models. We considered structural self-organization of both semantic and episodic memories with a symbolic representation of input events. Sequences of events are stored in EM and are used to build associations in SM. We demonstrated that integration of semantic and episodic memories improves the native operation of both types of memories. Experimental results are presented to illustrate how the two memories complement each other by improving recognition, prediction, and context-based generalization of individual memories.

Future Thinking: Children But Not Apes Consider Multiple Possibilities

When anticipating the future, we draw on our past experience but must take uncertainty into account; for example, while preparing for a trip, we might pack a raincoat and sunglasses because of unpredictable weather. New research shows that the ability to plan for multiple future possibilities may be present in human children from as early as 3-4 years of age, but appears to be lacking in non-human apes.

Characterizing the role of the hippocampus during episodic simulation and encoding

The hippocampus has been consistently associated with episodic simulation (i.e., the mental construction of a possible future episode). In a recent study, we identified an anterior-posterior temporal dissociation within the hippocampus during simulation. Specifically, transient simulation-related activity occurred in relatively posterior portions of the hippocampus and sustained activity occurred in anterior portions. In line with previous theoretical proposals of hippocampal function during simulation, the posterior hippocampal activity was interpreted as reflecting a transient retrieval process for the episodic details necessary to construct an episode. In contrast, the sustained anterior hippocampal activity was interpreted as reflecting the continual recruitment of encoding and/or relational processing associated with a simulation. In the present study, we provide a direct test of these interpretations by conducting a subsequent memory analysis of our previously published data to assess whether successful encoding during episodic simulation is associated with the anterior hippocampus. Analyses revealed a subsequent memory effect (i.e., later remembered > later forgotten simulations) in the anterior hippocampus. The subsequent memory effect was transient and not sustained. Taken together, the current findings provide further support for a component process model of hippocampal function during simulation. That is, unique regions of the hippocampus support dissociable processes during simulation, which include the transient retrieval of episodic information, the sustained binding of such information into a coherent episode, and the transient encoding of that episode for later retrieval.

Preparing for what might happen: An episodic specificity induction impacts the generation of alternative future events

A critical adaptive feature of future thinking involves the ability to generate alternative versions of possible future events. However, little is known about the nature of the processes that support this ability. Here we examined whether an episodic specificity induction - brief training in recollecting details of a recent experience that selectively impacts tasks that draw on episodic retrieval - (1) boosts alternative event generation and (2) changes one's initial perceptions of negative future events. In Experiment 1, an episodic specificity induction significantly increased the number of alternative positive outcomes that participants generated to a series of standardized negative events, compared with a control induction not focused on episodic specificity. We also observed larger decreases in the perceived plausibility and negativity of the original events in the specificity condition, where participants generated more alternative outcomes, relative to the control condition. In Experiment 2, we replicated and extended these findings using a series of personalized negative events. Our findings support the idea that episodic memory processes are involved in generating alternative outcomes to anticipated future events, and that boosting the number of alternative outcomes is related to subsequent changes in the perceived plausibility and valence of the original events, which may have implications for psychological well-being.

Adaptive false memory: Imagining future scenarios increases false memories in the DRM paradigm

Previous research has shown that rating words for their relevance to a future scenario enhances memory for those words. The current study investigated the effect of future thinking on false memory using the Deese/Roediger–McDermott (DRM) procedure. In Experiment 1, participants rated words from 6 DRM lists for relevance to a past or future event (with or without planning) or in terms of pleasantness. In a surprise recall test, levels of correct recall did not vary between the rating tasks, but the future rating conditions led to significantly higher levels of false recall than the past and pleasantness conditions did. Experiment 2 found that future rating led to higher levels of false recognition than did past and pleasantness ratings but did not affect correct recognition. The effect in false recognition was, however, eliminated when DRM items were presented in random order. Participants in Experiment 3 were presented with both DRM lists and lists of unrelated words. Future rating increased levels of false recognition for DRM lures but did not affect correct recognition for DRM or unrelated lists. The findings are discussed in terms of the view that false memories can be associated with adaptive memory functions.

Episodic future thinking improves children's prospective memory performance in a complex task setting with real life task demands

Research on children's prospective memory (PM) shows an increase of performance across childhood and provides first evidence that encoding strategies such as episodic future thinking (EFT; i.e., engaging in a vivid prospection of oneself performing future tasks) may improve performance. The present study aimed at testing whether the beneficial effects of EFT extend from typical lab-based tasks to more complex tasks with real life demands. Further, it was tested whether children's ability to project themselves into different perspectives (i.e., self-projection) moderates the effects of EFT encoding on PM. Overall, 56 children (mean age: M = 10.73 years) were included in this study who were randomly assigned to either an EFT or control condition. Children participated in a 'sightseeing tour' (ongoing activity) inside the lab with various socially relevant and neutral PM tasks embedded. Results showed significantly higher PM performance in the EFT compared to the control group. There was no difference between neutral and social PM tasks and no interaction between type of PM tasks with encoding condition. Further, self-projection did not moderate the effects of EFT encoding on PM. Results suggest that EFT is an effective strategy to improve children's everyday PM. These beneficial effects seem to occur independent from children's general ability to change perspectives and for different types of PM tasks.

Neural correlates of autobiographical problem-solving deficits associated with rumination in depression

BACKGROUND

Analytical rumination can be characterized as negative thoughts focused on searching for answers to personal problems. Failure to think concretely during autobiographical problem-solving (APS) is hypothesized to drive the inability of ruminators to generate effective solutions. Clarifying the brain correlates underlying APS deficits in depressed ruminators may identify novel biological targets for treatment.

METHOD

Forty participants (22 unmedicated depressed and 18 never-depressed adults) ranging in rumination engaged in APS and negative self-referential processing (NSP) of negative trait adjectives during fMRI. We contrasted activation during APS with activation during NSP to isolate regions contributing to APS.

RESULTS

Rumination was associated with having generated fewer solutions during APS and with a failure to recruit the angular gyrus (AG) and the medial frontal gyrus (MFG) during APS. Rumination was associated with greater MFG activation during NSP and stronger connectivity between the AG and the rostrolateral prefrontal cortex (RLPFC) during APS relative to NSP. Findings were not driven by clinical status.

LIMITATIONS

The use of an extreme groups approach can result in overestimation of effects sizes.

CONCLUSIONS

Ruminators fail to recruit regions with the default network (DN) that support APS. In particular, a failure to recruit the AG during APS may drive the abstract thinking style previously shown to explain depressed ruminator's difficulty generating concrete solutions. Targeting this mechanism directly may reduce rumination.

The role of conviction and narrative in decision-making under radical uncertainty

We propose conviction narrative theory (CNT) to broaden decision-making theory in order to better understand and analyse how subjectively means-end rational actors cope in contexts in which the traditional assumptions in decision-making models fail to hold. Conviction narratives enable actors to draw on their beliefs, causal models, and rules of thumb to identify opportunities worth acting on, to simulate the future outcome of their actions, and to feel sufficiently convinced to act. The framework focuses on how narrative and emotion combine to allow actors to deliberate and to select actions that they think will produce the outcomes they desire. It specifies connections between particular emotions and deliberative thought, hypothesising that approach and avoidance emotions evoked during narrative simulation play a crucial role. Two mental states, Divided and Integrated, in which narratives can be formed or updated, are introduced and used to explain some familiar problems that traditional models cannot.

A Role for the Left Angular Gyrus in Episodic Simulation and Memory

Functional magnetic resonance imaging (fMRI) studies indicate that episodic simulation (i.e., imagining specific future experiences) and episodic memory (i.e., remembering specific past experiences) are associated with enhanced activity in a common set of neural regions referred to as the core network. This network comprises the hippocampus, medial prefrontal cortex, and left angular gyrus, among other regions. Because fMRI data are correlational, it is unknown whether activity increases in core network regions are critical for episodic simulation and episodic memory. In the current study, we used MRI-guided transcranial magnetic stimulation (TMS) to assess whether temporary disruption of the left angular gyrus would impair both episodic simulation and memory (16 participants, 10 females). Relative to TMS to a control site (vertex), disruption of the left angular gyrus significantly reduced the number of internal (i.e., episodic) details produced during the simulation and memory tasks, with a concomitant increase in external detail production (i.e., semantic, repetitive, or off-topic information), reflected by a significant detail by TMS site interaction. Difficulty in the simulation and memory tasks also increased after TMS to the left angular gyrus relative to the vertex. In contrast, performance in a nonepisodic control task did not differ statistically as a function of TMS site (i.e., number of free associates produced or difficulty in performing the free associate task). Together, these results are the first to demonstrate that the left angular gyrus is critical for both episodic simulation and episodic memory.SIGNIFICANCE STATEMENT Humans have the ability to imagine future episodes (i.e., episodic simulation) and remember episodes from the past (i.e., episodic memory). A wealth of neuroimaging studies have revealed that these abilities are associated with enhanced activity in a core network of neural regions, including the hippocampus, medial prefrontal cortex, and left angular gyrus. However, neuroimaging data are correlational and do not tell us whether core regions support critical processes for simulation and memory. In the current study, we used transcranial magnetic stimulation and demonstrated that temporary disruption of the left angular gyrus leads to impairments in simulation and memory. The present study provides the first causal evidence to indicate that this region is critical for these fundamental abilities.

Episodic Future Thinking: Mechanisms and Functions

Episodic future thinking refers to the capacity to imagine or simulate experiences that might occur in one's personal future. Cognitive, neuropsychological, and neuroimaging research concerning episodic future thinking has accelerated during recent years. This article discusses research that has delineated cognitive and neural mechanisms that support episodic future thinking as well as the functions that episodic future thinking serves. Studies focused on mechanisms have identified a core brain network that underlies episodic future thinking and have begun to tease apart the relative contributions of particular regions in this network, and the specific cognitive processes that they support. Studies concerned with functions have identified several domains in which episodic future thinking produces performance benefits, including decision making, emotion regulation, prospective memory, and spatial navigation.

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.

The future is now: the impact of present fluency in judgments about the future

Recent research has emphasised the role of episodic memory in both remembering past events and in envisaging future events. On the other hand, it has been repeatedly shown that judgments about past events are affected by the fluency with which retrieval cues are processed. In this paper we investigate whether perceptual fluency also plays a role in judgments about future events. For this purpose we conducted four experiments. The first experiment replicated recent findings showing that stimuli that are processed fluently tend to be wrongly recognised as having been encountered in the past outside the laboratory walls [Brown, A. S., & Marsh, E. J. (2009). Creating illusions of past encounter through brief exposure. Psychological Science, 20, 534-538. doi: 10.1111/j.1467-9280.2009.02337.x ]. Two follow-up experiments using Brown and Marsh's [(2009). Creating illusions of past encounter through brief exposure. Psychological Science, 20, 534-538. doi: 10.1111/j.1467-9280.2009.02337 ] task tested the influence of perceptual fluency on future judgments. The fourth and last experiment was designed to rule out a potential confounding factor in the two previous experiments. Across experiments, we found that people rely on fluency when making judgments about events that are yet to come. These results suggest that fluency is an equally valid cue for past and future judgments.

The evolution of stories: from mimesis to language, from fact to fiction

Why a species as successful as Homo sapiens should spend so much time in fiction, in telling one another stories that neither side believes, at first seems an evolutionary riddle. Because of the advantages of tracking and recombining true information, capacities for event comprehension, memory, imagination, and communication evolved in a range of animal species—yet even chimpanzees cannot communicate beyond the here and now. By Homo erectus, our forebears had reached an increasing dependence on one another, not least in sharing information in mimetic, prelinguistic ways. As Daniel Dor shows, the pressure to pool ever more information, even beyond currently shared experience, led to the invention of language. Language in turn swiftly unlocked efficient forms of narrative, allowing early humans to learn much more about their kind than they could experience at first hand, so that they could cooperate and compete better through understanding one another more fully. This changed the payoff of sociality for individuals and groups. But true narrative was still limited to what had already happened. Once the strong existing predisposition to play combined with existing capacities for event comprehension, memory, imagination, language, and narrative, we could begin to invent fiction, and to explore the full range of human possibilities in concentrated, engaging, memorable forms. First language, then narrative, then fiction, created niches that altered selection pressures, and made us ever more deeply dependent on knowing more about our kind and our risks and opportunities than we could discover through direct experience. WIREs Cogn Sci 2018, 9:e1444. doi: 10.1002/wcs.1444

This article is categorized under: 1

Cognitive Biology > Evolutionary Roots of Cognition

2

Linguistics > Evolution of Language

3

Neuroscience > Cognition

Memory, mental time travel and The Moustachio Quartet

Mental time travel allows us to revisit our memories and imagine future scenarios, and this is why memories are not only about the past, but they are also prospective. These episodic memories are not a fixed store of what happened, however, they are reassessed each time they are revisited and depend on the sequence in which events unfold. In this paper, we shall explore the complex relationships between memory and human experience, including through a series of novels 'The Moustachio Quartet' that can be read in any order. To do so, we shall integrate evidences from science and the arts to explore the subjective nature of memory and mental time travel, and argue that it has evolved primarily for prospection as opposed to retrospection. Furthermore, we shall question the notion that mental time travel is a uniquely human construct, and argue that some of the best evidence for the evolution of mental time travel comes from our distantly related cousins, the corvids, that cache food for the future and rely on long-lasting and highly accurate memories of what, where and when they stored their stashes of food.

Increasing boys’ and girls’ intentions to avoid teenage pregnancy: a cluster randomised controlled feasibility trial of an interactive video drama-based intervention in post-primary schools in Northern Ireland

Background

Adolescent men have a vital yet neglected role in reducing unintended teenage pregnancy (UTP). There is a need for gender-sensitive educational interventions.

Objectives

To determine the value and feasibility of conducting an effectiveness trial of theIf I Were JackRelationship and Sexuality Education (RSE) intervention in a convenience quota sample of post-primary schools in Northern Ireland. Secondary objectives were to assess acceptability to schools, pupils (male/female, aged 14–15 years) and parents/guardians; to identify optimal delivery structures and systems; to establish participation rates and reach, including equality of engagement of different socioeconomic and religious types; to assess trial recruitment and retention rates; to assess variation in normal RSE practice; to refine survey instruments; to assess differences in outcomes for male and female pupils; to identify potential effect sizes that might be detected in an effectiveness trial and estimate appropriate sample size for that trial; and to identify costs of delivery and pilot methods for assessing cost-effectiveness.

Design

Cluster randomised Phase II feasibility trial with an embedded process and economic evaluation.

Intervention

A teacher-delivered classroom-based RSE resource – an interactive video drama (IVD) with classroom materials, teacher training and an information session for parents – to immerse young people in a hypothetical scenario of Jack, a teenager whose girlfriend is unintentionally pregnant. It addresses gender inequalities in RSE by focusing on young men and is designed to increase intentions to avoid UTP by encouraging young people to delay sexual intercourse and to use contraception consistently in sexual relationships.

Main outcome measures

Abstinence from sexual intercourse (delaying initiation of sex or returning to abstinence) or avoidance of unprotected sexual intercourse (consistent correct use of contraception). Secondary outcomes included Knowledge, Attitudes, Skills and Intentions.

Results

The intervention proved acceptable to schools, pupils and parents, as evidenced through positive process evaluation. One minor refinement to the parental component was required, namely the replacement of the teacher-led face-to-face information session for parents by online videos designed to deliver the intervention to parents/guardians into their home. School recruitment was successful (target 25%, achieved 38%). No school dropped out. Pupil retention was successful (target 85%, achieved 93%). The between-group difference in incidence of unprotected sex of 1.3% (95% confidence interval 0.55% to 2.2%) by 9 months demonstrated an effect size consistent with those reported to have had meaningful impact on UTP rates (resulting in an achievable sample size of 66 schools at Phase III). Survey instruments showed high acceptability and reliability of measures (Cronbach’s alpha: 0.5–0.7). Economic evaluation at Phase III is feasible because it was possible to (1) identify costs of deliveringIf I Were Jack(mean cost per pupil, including training of teachers, was calculated as £13.66); and (2) develop a framework for assessing cost-effectiveness.

Conclusion

Trial methods were appropriate, and recruitment and retention of schools and pupils was satisfactory, successfully demonstrating all criteria for progression to a main trial. The perceived value of culture- and gender-sensitive public health interventions has been highlighted.

Future work

Progression to a Phase III effectiveness trial.

Trial registration

Current Controlled Trials ISRCTN99459996.

Funding

This project was funded by the NIHR Public Health Research programme and will be published in full inPublic Health Research; Vol. 5, No. 1. See the NIHR Journals Library website for further project information.

Effects of aging on the relation between episodic simulation and prosocial intentions

Imagining helping a person in need can facilitate prosocial intentions. Here we investigated how this effect can change with aging. We found that, similar to young adults, older adults were more willing to help a person in need when they imagined helping that person compared to a baseline condition that did not involve helping, but not compared to a conceptual helping control condition. Controlling for heightened emotional concern in older adults revealed an age-related difference in the effect of imagining on willingness to help. While we observed age-related condition effects, we also found that the subjective vividness of scene imagery predicted willingness to help for both age groups. Our findings provide insight into the relations among episodic simulation, healthy aging, emotion, and prosociality. Implications for effects of episodic memory and aging on social decision-making are discussed.

Imagining the future: The core episodic simulation network dissociates as a function of timecourse and the amount of simulated information

Neuroimaging data indicate that episodic memory (i.e., remembering specific past experiences) and episodic simulation (i.e., imagining specific future experiences) are associated with enhanced activity in a common set of neural regions, often referred to as the core network. This network comprises the hippocampus, parahippocampal cortex, lateral and medial parietal cortex, lateral temporal cortex, and medial prefrontal cortex. Evidence for a core network has been taken as support for the idea that episodic memory and episodic simulation are supported by common processes. Much remains to be learned about how specific core network regions contribute to specific aspects of episodic simulation. Prior neuroimaging studies of episodic memory indicate that certain regions within the core network are differentially sensitive to the amount of information recollected (e.g., the left lateral parietal cortex). In addition, certain core network regions dissociate as a function of their timecourse of engagement during episodic memory (e.g., transient activity in the posterior hippocampus and sustained activity in the left lateral parietal cortex). In the current study, we assessed whether similar dissociations could be observed during episodic simulation. We found that the left lateral parietal cortex modulates as a function of the amount of simulated details. Of particular interest, while the hippocampus was insensitive to the amount of simulated details, we observed a temporal dissociation within the hippocampus: transient activity occurred in relatively posterior portions of the hippocampus and sustained activity occurred in anterior portions. Because the posterior hippocampal and lateral parietal findings parallel those observed during episodic memory, the present results add to the evidence that episodic memory and episodic simulation are supported by common processes. Critically, the present study also provides evidence that regions within the core network support dissociable processes.

Impact of age-relevant goals on future thinking in younger and older adults

This study investigated how personal goals influence age differences in episodic future thinking. Research suggests that personal goals change with age and like autobiographical memory, future thinking is thought to be organised and impacted by personal goals. It was hypothesised that cueing older adults with age-relevant goals should modulate age differences in episodic details and may also influence phenomenological characteristics of imagined scenarios. Healthy younger and older adults completed the Future Thinking Interview [Addis, D. R., Wong, A. T., & Schacter, D. L. (2008). Age-related changes in the episodic simulation of future events. Psychological Science, 19(1), 33-41. doi: 10.1111/j.1467-9280.2008.02043.x ] adapted to activate age-appropriate goals. Narratives were scored with an established protocol to obtain objective measures of episodic and semantic details. Subjective features such as emotionality and personal significance showed age differences as a function of goal domain while other features (e.g., vividness) were unaffected. However, consistent with prior reports, older adults produced fewer episodic details than younger adults and this was not modulated by goal domain. The results do not indicate that goal activation affects level of episodic detail. With respect to phenomenological aspects of future thinking, however, younger adults show more sensitivity to goal activation, compared with older adults.

Fluctuations of Attentional Networks and Default Mode Network during the Resting State Reflect Variations in Cognitive States: Evidence from a Novel Resting-state Experience Sampling Method

Neuroimaging studies have revealed the recruitment of a range of neural networks during the resting state, which might reflect a variety of cognitive experiences and processes occurring in an individual's mind. In this study, we focused on the default mode network (DMN) and attentional networks and investigated their association with distinct mental states when participants are not performing an explicit task. To investigate the range of possible cognitive experiences more directly, this study proposes a novel method of resting-state fMRI experience sampling, informed by a phenomenological investigation of the fluctuation of mental states during the resting state. We hypothesized that DMN activity would increase as a function of internal mentation and that the activity of dorsal and ventral networks would indicate states of top–down versus bottom–up attention at rest. Results showed that dorsal attention network activity fluctuated as a function of subjective reports of attentional control, providing evidence that activity of this network reflects the perceived recruitment of controlled attentional processes during spontaneous cognition. Activity of the DMN increased when participants reported to be in a subjective state of internal mentation, but not when they reported to be in a state of perception. This study provides direct evidence for a link between fluctuations of resting-state neural activity and fluctuations in specific cognitive processes.

Acting with the future in mind is impaired in long-term opiate users

RATIONALE

Episodic foresight is a fundamental human capacity. It refers to the ability to simulate future situations and organise current actions accordingly. While there is some evidence that opiate users have a reduced capacity to imagine themselves in future situations, no study to date has assessed whether opiate users show deficits in the ability to take steps in the present in anticipation of future needs.

OBJECTIVE

In this study, we assessed whether this functional aspect of episodic foresight is impaired in chronic opiate users and the extent to which any deficits are associated with executive dysfunction.

METHODS AND RESULTS

Participants were 33 long-term opiate users enrolled in an opiate substitution program and 34 controls. Relative to controls, the opiate users displayed significant impairment (medium effect size η ²_p = 0.08) in the two behavioural measures of episodic foresight used (items acquired and items used in the VW Foresight task). Furthermore, executive functioning was associated with foresight ability, although this was restricted to items acquired, and the associations were generally stronger for the control group.

CONCLUSIONS

These data provide important evidence suggesting that the functional aspect of episodic foresight is disrupted in long-term opiate users. While these deficits appear to have some links to impaired executive control, additional work is needed to gain a more complete understanding of the underlying cognitive and neural mechanisms involved. This, in turn, will have important implications for tailoring interventions with opiate users to maximise the likelihood of successful independent functioning.

Seeing light at the end of the tunnel: Positive prospective mental imagery and optimism in depression

Optimism is associated with positive outcomes across many health domains, from cardiovascular disease to depression. However, we know little about cognitive processes underlying optimism in psychopathology. The present study tested whether the ability to vividly imagine positive events in one's future was associated with dispositional optimism in a sample of depressed adults. Cross-sectional and longitudinal analyses were conducted, using baseline (all participants, N=150) and follow-up data (participants in the control condition only, N=63) from a clinical trial (Blackwell et al., 2015). Vividness of positive prospective imagery, assessed on a laboratory-administered task at baseline, was significantly associated with both current optimism levels at baseline and future (seven months later) optimism levels, including when controlling for potential confounds. Even when depressed, those individuals able to envision a brighter future were more optimistic, and regained optimism more quickly over time, than those less able to do so at baseline. Strategies to increase the vividness of positive prospective imagery may aid development of mental health interventions to boost optimism.

Episodic and Semantic Memory Contribute to Familiar and Novel Episodic Future Thinking

Increasing evidence indicates that episodic future thinking (EFT) relies on both episodic and semantic memory; however, event familiarity may importantly affect the extent to which episodic and semantic memory contribute to EFT. To test this possibility, two behavioral experiments were conducted. In Experiment 1, we directly compared the proportion of episodic and semantic memory used in an EFT task. The results indicated that more episodic memory was used when imagining familiar future events compared with novel future events. Conversely, significantly more semantic memory was used when imagining novel events compared with familiar events. Experiment 2 aimed to verify the results of Experiment 1. In Experiment 2, we found that familiarity moderated the effect of priming the episodic memory system on EFT; particularly, it increased the time required to construct a standard familiar episodic future event, but did not significantly affect novel episodic event reaction time. Collectively, these findings support the hypothesis that event familiarity importantly moderates episodic and semantic memory's contribution to EFT.

Mind-wandering as spontaneous thought: a dynamic framework

Most research on mind-wandering has characterized it as a mental state with contents that are task unrelated or stimulus independent. However, the dynamics of mind-wandering - how mental states change over time - have remained largely neglected. Here, we introduce a dynamic framework for understanding mind-wandering and its relationship to the recruitment of large-scale brain networks. We propose that mind-wandering is best understood as a member of a family of spontaneous-thought phenomena that also includes creative thought and dreaming. This dynamic framework can shed new light on mental disorders that are marked by alterations in spontaneous thought, including depression, anxiety and attention deficit hyperactivity disorder.