Ordering autobiographical experiences

Children's and adults' memory for the order of events in a museum: A preliminary study about temporal memory and its development using photo-taking and event-related potentials

Remembering personal past events and their order is important. These capacities are essential to episodic and autobiographical memory theories, are needed in the creation of life stories and vital in forensic settings. As important as memory for events and their order are, relatively little is known about their development and the underlying neural processes that support them. Further, there is a paucity of studies that have examined memory and its development for autobiographical, yet controlled, events. The objective of this study was to examine memory for the temporal order of naturalistic "real world" events by directly comparing 7-11-year-olds and adults using both behavioral and event-related potential (ERP) measures. Participants photographed events at a local museum and after a delay, we used their photographs to test their memory for the temporal order of pairs of the events. We experimentally manipulated the temporal distance between the event pairs (whether the two events photographed in the pair had a short or long temporal distance between them). A memory asymmetry manipulation was also included such that at retrieval, photographs were either presented in forward direction (photograph on the top configuration was taken before photograph shown on the bottom) or vice versa. Children and adults showed sensitivity to temporal distance between events based on behavior (in some instances accuracy was higher for long compared to short temporal distance) and ERP (differential neural processing for short and long temporal distance conditions). Only adults showed sensitivity to the memory asymmetry manipulation, and only when the events occurred within a short temporal distance. A larger study is needed to confirm the present "proof of concept" study results. There is strong potential of this photo paradigm approach, combining naturalistic events with ERP, in future developmental studies, and would further our understanding of how memory behavior and the neural processes underlying memory operate in the "real world."

Evidence for a metacognitive awareness of autobiographical memory organisation

Models of autobiographical memory (AM) recall posit some form of control process, but the extent to which we can reflect on this form of retrieval is under-researched. Here we propose a method for measuring such metacognitive awareness in AM. Since the verification of personal facts is difficult, we based our design on AM organisation. AMs are proposed to be organised into a coherent life story, that is, a subjective chronology reflecting the goals of the individual over time. We investigated the metacognitive awareness of this coherence. Eighty-three participants generated AMs and made two judgements of order for pairs of memories and gave a confidence rating. We found that participants were indeed able to distinguish pairs of memories that were coherent with their life story chronology from pairs which were not. We also found a significant effect of response time and task difficulty on confidence, suggesting that judgement of order fluency was determinant for metacognitive evaluation. This suggests common properties between metacognitive abilities related to autobiographical memory and those related to other forms of memory.

Longitudinal Development of Memory for Temporal Order in Early to Middle Childhood

Existing studies examining the development of temporal order memory show that although young children perform above chance on some tasks assessing temporal order memory, there are significant age-related differences across childhood. Yet, the trajectory of children's ability to retrieve temporal order remains unclear as existing conclusions are drawn from cross-sectional studies. The present study utilized an accelerated longitudinal design in order to characterize the developmental trajectory of temporal order memory in a sample of 200 healthy 4- to 8-year-old children. Specifically, two tasks commonly used in the literature were tested longitudinally: a primacy judgment task and an ordering task. Results revealed that, even after controlling for differences in IQ, linearly increasing trajectories characterized age-related change in performance for both tasks; however, change appeared greater for the temporal ordering task. Further, performance on the two tasks was positively related, suggesting shared underlying mechanisms. These findings provide a more thorough understanding of temporal order memory in early to middle childhood by characterizing the developmental trajectories of two commonly used tasks and have important implications for our understanding of children's developing memory more broadly.

Context Memory in Alzheimer's Disease: The "Who, Where, and When"

Objective

Context memory, a component of episodic system, refers to the ability to retrieve conditions under which an event has occurred, such as who was present during that event and where and when it occurred. Context memory has been found to be compromised in older adults, an issue that we investigated in Alzheimer's disease (AD).

Methods

Thirty-one participants with AD and 35 older adults were asked to generate three autobiographical events. Afterward, they were asked to remember the names of all people who were evoked during the events, and the names for any location that was mentioned during the events. Participants were also asked to remember the year, season, month and day of the week when the events occurred.

Results

Compared to older adults, participants with AD showed lower memory for "who" (p < .001), "where" (p < .05), and "when" (p < .01). Compared to "who" and "where", both participants with AD and older adults showed pronounced difficulties in remembering the "when".

Conclusion

these findings highlight difficulties in remembering temporal information as an indication of context memory decline in AD. The difficulties in retrieving temporal information are discussed in terms of timing failures and hippocampal degenerations in AD.

Chronologically organized structure in autobiographical memory search

Each of us has a rich set of autobiographical memories that provides us with a coherent story of our lives. These memories are known to be highly structured both thematically and temporally. However, it is not known how we naturally tend to explore the mental timeline of our memories. Here we developed a novel cued retrieval paradigm in order to investigate the temporal element of memory search. We found that, when asked to search for memories in the days immediately surrounding a salient cued event, participants displayed a marked set of temporal biases in their search patterns. Specifically, participants first tended to jump back in time and retrieve memories from the day prior to the cued event. Following this they then transitioned forward in time, and retrieved memories from the day after the cued event. This pattern of results replicated in a second experiment with a much larger group of participants, and a different method of cueing the memories. We argue that this set of temporal biases is consistent with memory search conforming to a temporally ordered narrative structure.

Absolute and relative temporal order memory for performed activities following stroke

Reconstructing the temporal order of events is a crucial part of episodic memory. The temporal dimension, however, is often discarded in clinical settings, and measurements of true temporal aspects of episodic memory are scarce. The present study assessed temporal memory in stroke patients and in age- and education-matched healthy controls. Both groups underwent a standardized neuropsychological examination. We asked participants afterwards to reconstruct the order of tests they had performed, measured in absolute temporal order (event placed on correct moment in sequence) and relative temporal order (event placed correctly relative to directly preceding and following events). The aim of the study was to examine how serial-position curve effects (measuring absolute temporal order anchored in exact time) and how relative temporal order memory (anchored to other events) may differ in a group of cerebral stroke patients. Another aim was to link temporal order memory deficits with established neuropsychological measures of cognitive functioning. Although item identification was comparable in both groups, absolute temporal order memory was impaired in patients: A total of 43% of the patients lacked the expected primacy and recency effects (serial position effect). In addition, relative temporal order memory was affected in this group as well, F(1, 70) = 4.08, p < .05; 25% of the patients were impaired in reconstructing the relative temporal order (p = .019, Fisher's Exact Test). Both absolute and relative temporal order memory performance related to the domains of executive functioning and memory. Our results suggest that it is important to test both absolute and relative temporal order memory, especially because these types of memory depend on different anchors, either on time or on adjacent events.

Bringing order to life events: memory for the temporal order of autobiographical events over an extended period in school-aged children and adults

Remembering temporal information associated with personal past events is critical. Yet little is known about the development of temporal order memory for naturally occurring events. In the current research, 8- to 10-year-old children and adults took photographs daily for 4 weeks. Later, they participated in a primacy/recency task (were shown 2 of their photographs and decided which event occurred first) and an ordering task (ordered 12 photographs taken over the 4-week period). All participants showed above-chance performance in primacy/recency; adults were more accurate than children. For ordering, children and adults showed similar patterns and performance was relatively low. This study has implications for autobiographical memory theories and suggests that ordering accuracy might not be necessary for adult-like autobiographical memory. Practical and legal implications of the findings also are discussed.

Functional anatomy of temporal organisation and domain-specificity of episodic memory retrieval

Episodic memory provides information about the "when" of events as well as "what" and "where" they happened. Using functional imaging, we investigated the domain specificity of retrieval-related processes following encoding of complex, naturalistic events. Subjects watched a 42-min TV episode, and 24h later, made discriminative choices of scenes from the clip during fMRI. Subjects were presented with two scenes and required to either choose the scene that happened earlier in the film (Temporal), or the scene with a correct spatial arrangement (Spatial), or the scene that had been shown (Object). We identified a retrieval network comprising the precuneus, lateral and dorsal parietal cortex, middle frontal and medial temporal areas. The precuneus and angular gyrus are associated with temporal retrieval, with precuneal activity correlating negatively with temporal distance between two happenings at encoding. A dorsal fronto-parietal network engages during spatial retrieval, while antero-medial temporal regions activate during object-related retrieval. We propose that access to episodic memory traces involves different processes depending on task requirements. These include memory-searching within an organised knowledge structure in the precuneus (Temporal task), online maintenance of spatial information in dorsal fronto-parietal cortices (Spatial task) and combining scene-related spatial and non-spatial information in the hippocampus (Object task). Our findings support the proposal of process-specific dissociations of retrieval.

The short and long of it: neural correlates of temporal-order memory for autobiographical events

Previous functional neuroimaging studies of temporal-order memory have investigated memory for laboratory stimuli that are causally unrelated and poor in sensory detail. In contrast, the present functional magnetic resonance imaging (fMRI) study investigated temporal-order memory for autobiographical events that were causally interconnected and rich in sensory detail. Participants took photographs at many campus locations over a period of several hours, and the following day they were scanned while making temporal-order judgments to pairs of photographs from different locations. By manipulating the temporal lag between the two locations in each trial, we compared the neural correlates associated with reconstruction processes, which we hypothesized depended on recollection and contribute mainly to short lags, and distance processes, which we hypothesized to depend on familiarity and contribute mainly to longer lags. Consistent with our hypotheses, parametric fMRI analyses linked shorter lags to activations in regions previously associated with recollection (left prefrontal, parahippocampal, precuneus, and visual cortices), and longer lags with regions previously associated with familiarity (right prefrontal cortex). The hemispheric asymmetry in prefrontal cortex activity fits very well with evidence and theories regarding the contributions of the left versus right prefrontal cortex to memory (recollection vs. familiarity processes) and cognition (systematic vs. heuristic processes). In sum, using a novel photo-paradigm, this study provided the first evidence regarding the neural correlates of temporal-order for autobiographical events.

Ordering the components of autobiographical events

Memory for the temporal order of the components of autobiographical events was examined in two experiments. Experiments 1 and 2 examined the relationship between reaction times to recognise photographs of the components of events and ordering of these photographs. Reaction times were not related to true event position, nor to assigned temporal position, in a manner consistent with an activation strength model of temporal ordering. In contrast, ordering performance was found to be related to event vividness ratings, ability to classify a photograph as one the participant had taken, and retention interval. These findings are all consistent with the hypothesis that the order of an autobiographical event's components is determined by the associative structure that links each component to its general event memory. Overall, memory for the order of the components of autobiographical events may be initially based on associations between the event components and their general event memory representation. These associations appear to decay rapidly leaving only reconstructive ability as the determinant of event component order.

Memory for time: how people date events

The effect of different formats on the accuracy of dating news and the distribution of personal events was examined in four conditions. In the first, participants had to date events in the absolute time format (e.g., "July 2004"), and in the second, they had to date events in the relative time format (e.g., "3 weeks ago"). In the other conditions, they were asked to choose between the two formats. We found a small backward telescoping effect for recent news events and a large forward telescoping effect for remote events. Events dated in the absolute time format were more accurate than those dated in the relative time format. Furthermore, participants preferred to date news events with the relative time format and personal events with the absolute time format, as well as preferring to date remote events in the relative time format and recent events in the absolute time format.

Ordering our world: An examination of time in autobiographical memory

In two studies people judged the order in which two real-world events occurred. Ordering performance was better for events that were recent or widely separated in time. Ordering performance was also consistently related to predicted event memorability and to the amount of processing given to an event during encoding. Ordering performance was not consistently related to the person-typicality, pleasantness, or emotional intensity of the events, and was also not related to whether the two events judged came from the same thematic category. These results suggest that memory for event order is not entirely reconstructed from event content. We suggest that the self-concept may sometimes serve as an implicit timekeeper in autobiographical memory.

Themes, events, and episodes in autobiographical memory

The process by which experience is divided into events was examined. Experiment 1 involved diarists recording their experiences over a 3-month period. Diary entries were later transcribed onto cards and the diarists arranged their cards so as to define events they had experienced, and in a separate phase arranged their cards so as to describe the themes that reflected their life. Examination of event- and theme-building strategies indicated that boundaries were frequently used, and events and themes were often formed from clusters of experience combined using content association rather than temporal sequence. Experiment 2 involved photographs taken by the participants, employed the same procedures as in Experiment 1, and revealed event- and theme-building strategies similar to those identified in Experiment 1. In Experiment 3 the size of the stimulus set from which events and themes were constructed was manipulated; this did not influence construction strategies. Overall, the experiments show that both autobiographical events and themes frequently consist of episodes taken from more than 1 day.