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.     

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.     

The proximate memory mechanism underlying the survival-processing effect: Richness of encoding or interactive imagery?

Nairne and collaborators showed that assessing the relevance of words in the context of an imagined survival scenario boosts memory for these words. Although this survival-processing advantage has attracted a considerable amount of research, little is known about the proximate memory mechanism mediating this effect. Recently, Kroneisen and Erdfelder (2011) argued that it is not survival processing itself that facilitates recall but rather the richness and distinctiveness of encoding that is triggered by the survival-processing task. Alternatively, however, it is also conceivable that survival processing fosters interactive imagery, a process known to improve associative learning. To test these explanations we compared relevance-rating and interactive imagery tasks for survival and control scenarios. Results show that the survival advantage replicates in the relevance-rating condition but vanishes in the interactive imagery condition. This refutes the interactive imagery explanation and corroborates the richness-of-encoding hypothesis of the survival-processing effect.     

Age-related differences in episodic feeling-of-knowing arise from differences in memory performance

Previous studies about the effects of ageing on the episodic feeling-of-knowing (FOK) accuracy and its underlying processes have yielded conflicting results. Recent work suggests that using alternative measures to gamma correlations might allow more accurate and informative interpretations of metamemory performance in ageing. We therefore investigated this issue with a large sample of 59 young and 61 older participants using alternative signal-detection theory (SDT) measures. These measures (receiver operating characteristic curves and Brier score) are recommended in the literature and able to reveal the characteristic profile of impairment in ageing. Our results suggest that the FOK accuracy deficit observed in the literature arises from differences in memory performance. This observation provides a convenient explanation to the previous discrepancies and furthermore supports the interest of the use of SDT-derived measures in the frame of metamemory.     

Visual perspective in autobiographical memories: Reliability,consistency, and relationship to objective memory performance

Visual perspective in autobiographical memories was examined in terms of reliability, consistency, and relationship to objective memory performance in a sample of 99 individuals. Autobiographical memories may be recalled from two visual perspectives—a field perspective in which individuals experience the memory through their own eyes, or an observer perspective in which individuals experience the memory from the viewpoint of an observer in which they can see themselves. Participants recalled nine word-cued memories that differed in emotional valence (positive, negative and neutral) and rated their memories on 18 scales. Results indicate that visual perspective was the most reliable memory characteristic overall and is consistently related to emotional intensity at the time of recall and amount of emotion experienced during the memory. Visual perspective is unrelated to memory for words, stories, abstract line drawings or faces.     

Gender differences in autobiographical memory: Developmental and methodological considerations

Gender differences have surfaced in inconsistent ways in autobiographical memory studies. When apparent, researchers find gender differences such that women report more vivid memory experiences than men and women include more details about emotions, about other people, and about the meaningfulness of their memories. Specifically, females include more emotion, more elaboration, and a greater sense of connectedness to others in their narratives, and we consider the possible connection between these tendencies and women’s advantage on a number of autobiographical and episodic memory tasks. However, not all studies of autobiographical memory find gender differences. We propose that gender differences in autobiographical memory development and interpersonal socialization contribute to the differences found, and that gender differences can be attributed, at least in part, to the influence of conversations with parents when autobiographical memory skills are developing. An examination of studies in which gender differences are not found suggests that specific instructions, context, gender salience, and the type of autobiographical memory measure used can mitigate gender differences. We conclude by outlining future directions for research, including longitudinal studies and experiments designed to systematically examine gender in autobiographical memory for its own sake.     

Episodic future thinking in children compared to adolescents

Episodic thinking involves the ability to re-create past and to construct future personal events, which contain event-specific (episodic) and general (semantic) details. The richness of episodic thought for past events improves as children move into adolescence. The current study aims to examine changes in episodic future thinking and to establish the cognitive underpinning of these changes. Typically developing children (n = 14) and adolescents (n = 15) were tested using an adapted version of the Child Autobiographical Interview (CAI) that required generation of past and future personally relevant events. Relational memory and executive skills were also examined. Significant developmental gains were found in richness of events recall across temporal directions (past and future) and across different types of details (episodic and semantic). Developmental gains in richness of past events were also shown to correspond to developmental gains in generation of future events. Moreover, developmental changes in relational memory and (to a lesser extent) executive functions were found to relate to increases in the amount of episodic (but not semantic) details provided. Our study highlighted the similarities between past and future episodic thinking in typically developing children and adolescents. It also raises a possibility that children with developmental and neurological disorders with impaired relational memory and/or executive skills may be at risk of difficulties with episodic thinking.