Priming autobiographical memories: How recalling the past may affect everyday forms of autobiographical remembering

This study investigated the idea that when one recalls past episodes, that the content of those memories will activate additional episodic memories with like content, and such memories will then have the potential of surfacing in subsequent acts of involuntary and voluntary recall. We tested the episodic content priming hypothesis in two experiments. In Experiment 1, priming group participants first recalled memories about specific activities or events and then they were subsequently engaged in a word-cue voluntary autobiographical memory task. The results showed that priming group participants produced more episodic memories involving the primed content on this task than control participants occupied in the same task. In Experiment 2, episodic content priming was further tested on a measure of involuntary autobiographical memory (i.e., the vigilance task). The results on this task also revealed support for the episodic content priming hypothesis, including after a delay of 24 h.     

The role of lifetime periods in the organisation of episodic memories

ABSTRACT

Research on the nature of episodic memory associations has suggested that episodic memories are associated by conceptual knowledge, where memories cluster around the same content (e.g. memories about the same people) or general-event knowledge, where memories cluster around extended events (e.g. a holiday in London), repeated events (e.g. Sunday walks in the park), or causally related events (i.e. where one event leads to another). Research has also suggested that episodic memories are associated by lifetime periods (e.g. when I was in high school), where memories cluster within lifetime periods. However, it is unclear whether episodic memories can be associated solely by lifetime periods, or if such associations are subordinate to conceptual or general-event associations. To answer this question, we reanalysed a large sample of involuntary memory chains (Mace, J. H., Clevinger, A. M., & Bernas, R. S. (2013). Involuntary memory chains: What do they tell us about autobiographical memory organisation? Memory, 21, 324–335). The results of this analysis suggested that lifetime periods associations are subordinate to conceptual and general-event associations, as lifetime periods were found to cluster within the latter two associations. The potential functions of this organisation are discussed.     

Episodic future thought: Contributions from working memory

The ability to imagine hypothetical events in one’s personal future is thought to involve a number of constituent cognitive processes. We investigated the extent to which individual differences in working memory capacity contribute to facets of episodic future thought. College students completed simple and complex measures of working memory and were cued to recall autobiographical memories and imagine future autobiographical events consisting of varying levels of specificity (i.e., ranging from generic to increasingly specific and detailed events). Consistent with previous findings, future thought was related to analogous measures of autobiographical memory, likely reflecting overlapping cognitive factors supporting both past and future thought. Additionally, after controlling for autobiographical memory, residual working memory variance independently predicted future episodic specificity. We suggest that when imagining future events, working memory contributes to the construction of a single, coherent, future event depiction, but not to the retrieval or elaboration of event details.     

Altering access to autobiographical episodes with prior semantic knowledge

Within autobiographical knowledge, semantic and episodic memory are traditionally considered separate, but newer models place them along a continuum, which raises the possibility of an intermediate form of knowledge - personal semantics. This study tested how different types of semantics – general semantics and two forms of personal semantics – impact access to personal episodic memories. In two experiments, participants made a series of true/false judgments about a prime statement, which reflected a general semantic fact, a context-dependent (e.g., repeated event) or context-independent (e.g., trait), personal semantic fact and then retrieved a specific past episodic memory. There was a significantly stronger priming effect for accessing specific episodic memories after judging personal semantic facts versus general facts. We also found that context-dependent and -independent personal semantic facts had separable priming effects on episodic memory. These findings support a continuum model of memory and verifies that there are multiple forms of personal knowledge.     

Imagining novel futures: The roles of event plausibility and familiarity

The constructive episodic simulation hypothesis suggests that episodic memory supports the simulation of future events through extraction and recombination of stored information. The current study explicitly investigated the use of past episodic thought in the simulation of future scenarios. Participants simulated one of three possible scenarios, differing in plausibility and participants’ prior experience of similar events. Participants recorded related memories and whether they were explicitly used during future event simulation. Memories were rated for source (self-experienced, other-experienced, or media). Findings suggest prior experience and event plausibility did not impact upon ease of future event simulation or the extent of memory usage during simulations. Differences emerged in the source of information used to assist future event simulation. These findings provide support for the hypothesis that episodic memories from a variety of sources are recombined when generating future simulations of novel events.     

年龄、焦虑与情节记忆之内容与来源的关系

将情节记忆区分为内容记忆和来源记忆,筛选年老和年轻的高、低特质焦虑者完成记忆任务,以探讨情节记忆年老化的选择性和变异性及其与焦虑之间的联系。两项实验结果表明来源记忆是否随增龄而有选择性受损受来源性质影响,与来源呈现方式和来源识记意识性无关。焦虑干扰了老年组的记忆操作,是老年人情节记忆存在个体差异的原因之一;但焦虑对青年组没有不利影响,提示焦虑调节两类记忆的年龄差异。     

Specificity deficit in the recollection of emotional memories in schizophrenia

The influence of emotion on episodic and autobiographical memory in schizophrenia was investigated. Using an experiential approach, the states of awareness accompanying recollection of pictures from the IAPS and of associated autobiographical memories was recorded. Results show that schizophrenia impairs episodic and autobiographical memories in their critical feature: autonoetic awareness, i.e., the type of awareness experienced when mentally reliving events from one's past. Schizophrenia was also associated with a reduction of specific autobiographical memories. The impact of stimulus valence on memory performance was moderated by clinical status. Patients with schizophrenia recognized more positive than negative pictures, and recalled more positive than negative autobiographical memories while controls displayed the opposite pattern. A hypothesis in terms of a fundamental executive deficit underlying these impairments is proposed.     

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.     

Mental time travel for self and other in three- and four-year-old children

Humans possess the unique ability to mentally travel backward in time to re-experience past events (i.e., episodic memory) and forward in time to pre-experience future events (i.e., episodic foresight). Although originally viewed as different cognitive skills, they are now both viewed as components of the episodic memory system. Recently, it has been suggested that the episodic system may allow us to not only pre-experience and predict our own future but also that of another person. In the current study, we investigate this possibility by examining the ability of three- and four-year-old children to plan for their own future and for that of another person. We found that both three- and four-year-old children performed equally, when planning for their own future or when planning for the experimenter's future. These data are consistent with the finding that planning for someone else's future recruits the same neural structures that are used when planning for one's own future.     

Cognitive processes supporting episodic memory formation in childhood: The role of source memory,binding, and executive functioning

Episodic memories contain various forms of contextual detail (e.g., perceptual, emotional, cognitive details) that need to become integrated. Each of these contextual features can be used to attribute a memory episode to its source, or origin of information. Memory for source information is one critical component in the formation of episodic memories. Likewise, the establishment of episodic memories also requires binding, which reflects the process of encoding the relations among stimuli and provides the experience that certain features of a memory episode belong together. The aims of the present review are to explore the roles of (1) cognitive and neural mechanisms involved in source memory and binding and how the development of these cognitive processes relates to episodic memory formation in childhood and (2) other higher-order cognitive processes, namely executive functioning, in early episodic memory development. We conclude by examining the challenges within this field of research, highlighting the role of other cognitive processes (e.g., sense of self, language, use of strategies) that may contribute to episodic memory formation, addressing areas that can be improved with additional research, and exploring directions for future work.     

How we have fallen: implicit trajectories in collective temporal thought

ABSTRACT

Memory may play a critical role in the ability to imagine events in the future. While most work on this relation has concerned episodic memory and simulated episodic events in the future, the current study examines how collective memories relate to imagination for the collective future. Two thousand American participants provided events for (1) America’s origins, (2) normative events that all Americans should remember, and (3) events in America’s future. Each event was rated for emotional valence. Whereas collective memories – particularly origin events – showed pronounced positivity biases, there was a negativity bias in collective future thought, indicating an implicit trajectory of decline in Americans’ representations of their nation across time. Imagination for the social future may not be simulated based on the template of collective memories, but may rather relate to the past in a way that is mediated by cultural narrative schemata.     

Coding of stimuli by animals: Retrospection, prospection, episodic memory and future planning

When animals code stimuli for later retrieval they can either code them in terms of the stimulus presented (as a retrospective memory) or in terms of the response or outcome anticipated (as a prospective memory). Although retrospective memory is typically assumed (as in the form of a memory trace), evidence of prospective coding has been found when response intentions and outcomes are particularly salient. At a more abstract level is the question of whether animals are able figuratively to travel back in time to recover memories of past events (episodic memory) and forward in time to predict future events (future planning). Although what would constitute adequate evidence of episodic memory and future planning is controversial, preliminary evidence suggests that animals may be capable of both forms of subjective time travel.     

Indirect cueing elicits distinct types of autobiographical event representations

Studies that distinguish among believed memories, believed-not-remembered events (e.g., family stories), and nonbelieved memories (i.e., memories no longer believed to have occurred) typically rely on experimenter provided or overtly elicited events. These methods may mis-estimate the frequency and nature of such events in everyday memory. Three studies examined whether such events would be elicited via indirect cueing. Participants recalled and rated events on autobiographical belief, recollection, and other characteristics associated with remembering. All three event types resulted, but with a low rate of nonbelieved memories. Believed and nonbelieved memories received similar perceptual and re-experiencing ratings, and both exceeded believed-not-remembered events. Lifespan cueing found nonbelieved memories to be most frequent in middle childhood (ages 6–11). Cueing for “events” vs. “memories” revealed that “memory” cues lead to retrieval of a more homogeneous set of events and differences when predicting autobiographical belief and recollection. These studies support the distinction between autobiographical belief and recollection for autobiographical events.     

Imagining novel futures: the roles of event plausibility and familiarity

The constructive episodic simulation hypothesis suggests that episodic memory supports the simulation of future events through extraction and recombination of stored information. The current study explicitly investigated the use of past episodic thought in the simulation of future scenarios. Participants simulated one of three possible scenarios, differing in plausibility and participants' prior experience of similar events. Participants recorded related memories and whether they were explicitly used during future event simulation. Memories were rated for source (self-experienced, other-experienced, or media). Findings suggest prior experience and event plausibility did not impact upon ease of future event simulation or the extent of memory usage during simulations. Differences emerged in the source of information used to assist future event simulation. These findings provide support for the hypothesis that episodic memories from a variety of sources are recombined when generating future simulations of novel events.     

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.     

Exploring self-defining memories in schizophrenia

Previous studies have shown that patients with schizophrenia are impaired in recalling specific events from their personal past. However, the relationship between autobiographical memory impairments and disturbance of the sense of identity in schizophrenia has not been investigated in detail. In this study the authors investigated schizophrenic patients’ ability to recall self-defining memories; that is, memories that play an important role in building and maintaining the self-concept. Results showed that patients recalled as many specific self-defining memories as healthy participants. However, patients with schizophrenia exhibited an abnormal reminiscence bump and reported different types of thematic content (i.e., they recalled less memories about past achievements and more memories regarding hospitalisation and stigmatisation of illness). Furthermore, the findings suggest that impairments in extracting meaning from personal memories could represent a core disturbance of autobiographical memory in patients with schizophrenia.