Stability in autobiographical memories

A total of 30 undergraduates recalled the same 20 autobiographical memories at two sessions separated by 2 weeks. At each session they dated their memories and rated them on 18 properties commonly studied in autobiographical memory experiments. Individuals showed moderate stability in their ratings on the 18 scales (r approximately .5), with consistency of dating being much higher (r = .96). There was more stability in the individuals' average rating on each scale (r approximately .8), even when the averages were calculated on different memories in the different sessions. The results are consistent with a constructive view of autobiographical memory, in which stable individual differences in cognitive style are important.     

Source misattributions may increase the accuracy of source judgments

Misattribution of remembered information from one source to another is commonly associated with false memories, but we demonstrate that it also may underlie memories that accord with past events. Participants imagined drawings of objects in four different locations. For each, a drawing of a similarly shaped object was seen in the same location, a different location, or not seen. When tested on memory for objects' origin (seen/imagined) and location, more false "seen" responses, but also more correct location responses, were given to imagined objects if a similar object had been seen, versus not seen, in the same location. We argue that misattribution of feature information (e.g., shape, location) from seen objects to similar imagined ones increased false memories of seeing objects but also increased correct location memories, provided the misattributed location matched the imagined objects' location. Thus, consistent with the source-monitoring framework, imperfect source-attribution processes underlie false and true memories.     

Episodic-like memory in pigeons

It has been proposed that memory for personal experiences (episodic memory, rather than semantic memory) relies on the conscious review of past experience and thus is unique to humans. In an attempt to demonstrate episodic-like memory in animals, we first trained pigeons to respond to the (nonverbal) question "Did you just peck or did you just refrain from pecking?" by training them on a symbolic matching task with differential responding required to the two line-orientation samples and reinforcing the choice of a red comparison if they had pecked and the choice of a green comparison if they had not pecked. Then, in Experiment 1, after providing the conditions for (but not requiring) the pigeons to peck at one new stimulus (a yellow hue) but not at another (a blue hue), we tested them with the new hue stimuli and the red and green comparisons. In Experiment 2, we tested the pigeons with novel stimuli (a circle, which they spontaneously pecked, and a dark response key, which they did not peck) and the red and green comparisons. In both experiments, pigeons chose the comparison appropriate to the response made to the test stimulus. Thus, the pigeons demonstrated that they could remember specific details about their past experiences, a result consistent with the notion that they have the capacity for forming episodic-like memories.     

Gender Identity Predicts Autobiographical Memory Phenomenology

Gender differences emerge regularly in autobiographical memory research. We suggest that gender differences in phenomenological self‐report measures of autobiographical memory are rooted in gender identity rather than categorical gender. Reminiscing about the past is perceived as a female‐typical activity, and therefore, gender‐typical individuals will conform to these stereotypes. In this study, 196 participants, age 18–40, each rated the phenomenology of four event memories. Ratings of feminine gender identity, also completed by participants, consistently correlated with MEQ scores, indicating that greater endorsement of feminine gender norms predicted higher memory quality and valence. Masculine gender identity also correlated with MEQ scores, but these correlations were less consistent. Findings suggest that a focus on gender identity can both explain the source of some gender differences in autobiographical memory and potentially explain some inconsistencies in the current literature.Copyright © 2016 John Wiley & Sons, Ltd.     

Why recall our highs and lows: relations between memory functions, age, and well-being

This study examined whether positive and negative memories (life story high and low points) were differentially used for reminiscence functions concerning self and social aspects of reminiscing, and relations between function use and well-being in two age groups. Life story high and low points were collected from a sample of emerging (n =56) and older (n =55) adults, as well as a measure of the use of these memories for the self-functions of death preparation, identity, and problem solving, and the social functions of conversation and teach/inform, and a measure of psychological well-being. Memories were also coded for whether or not they contained a redemptive narrative structure (from emotionally negative to emotionally positive). Results showed that the endorsement of reminiscence functions did differ by memory type, with high points more often endorsed for the functions of identity, teach/inform, and conversation than low points. These main effects were qualified by memory type x age interactions. The use of these functions for each kind of memory was also related to well-being, but differentially for older and younger people, and redemptive sequencing was especially important to the well-being of the younger group. Findings are discussed in terms of the importance of different emotional memories for self and well-being at different points in the lifespan.     

Emotion, memory, and attention in the taboo Stroop paradigm

This study tested the binding hypothesis: that emotional reactions trigger binding mechanisms that link an emotional event to salient contextual features such as event location, a frequently recalled aspect of naturally occurring flash-bulb memories. Our emotional events were taboo words in a Stroop color-naming task, and event location was manipulated by presenting the words in different task-irrelevant screen locations. Seventy-two participants named the font color of taboo and neutral words, with instructions to ignore word meaning; in one condition, several words were location consistent (i.e., always occupied the same screen location), whereas in another condition, several colors were location consistent. Then, in a surprise recognition memory test, participants recalled the locations of location-consistent words or colors. Although attention enhanced overall location memory for colors (the attended dimension during color naming), emotion (taboo vs. neutral words) enhanced location memory for words but not colors. These results support the binding hypothesis but contradict the hypothesis that emotional events induce image-like memories more often than non-emotional events.     

Electrolytic lesions of dorsal CA3 impair episodic-like memory in rats

Episodic memory is the ability to recollect one's past experiences occurring in an unique spatial and temporal context. In non-human animals, it is expressed in the ability to combine "what", "where" and "when" factors to form an integrated memory system. During the search for its neural substrates, the hippocampus has attracted a lot of attentions. Yet, it is not yet possible to induce a pure episodic-like memory deficit in animal studies without being confounded by impairments in the spatial cognition. Here, we present a lesion study evidencing direct links between the hippocampus CA3 region and the episodic-like memory in rats. In a spontaneous object exploration task, lesioned rats showed no interaction between the temporal and spatial elements in their memory associated with the objects. In separate tests carried out subsequently, the same animals still expressed abilities to process spatial, temporal, and object recognition memory. In conclusions, our results support the idea that the hippocampus CA3 has a particular status in the neural mechanism of the episodic-like memory system. It is responsible for combining information from different modules of cognitive processes.     

Why recall our highs and lows: Relations between memory functions,age, and well-being

This study examined whether positive and negative memories (life story high and low points) were differentially used for reminiscence functions concerning self and social aspects of reminiscing, and relations between function use and well-being in two age groups. Life story high and low points were collected from a sample of emerging (n =56) and older (n =55) adults, as well as a measure of the use of these memories for the self-functions of death preparation, identity, and problem solving, and the social functions of conversation and teach/inform, and a measure of psychological well-being. Memories were also coded for whether or not they contained a redemptive narrative structure (from emotionally negative to emotionally positive). Results showed that the endorsement of reminiscence functions did differ by memory type, with high points more often endorsed for the functions of identity, teach/inform, and conversation than low points. These main effects were qualified by memory type × age interactions. The use of these functions for each kind of memory was also related to well-being, but differentially for older and younger people, and redemptive sequencing was especially important to the well-being of the younger group. Findings are discussed in terms of the importance of different emotional memories for self and well-being at different points in the lifespan.     

Gender differences in memory for objects and their locations: a study on automatic versus controlled encoding and retrieval contexts

Object-location memory is the only spatial task where female subjects have been shown to outperform males. This result is not consistent across all studies, and may be due to the combination of the multi-component structure of object location memory with the conditions under which different studies were done. Possible gender differences in object location memory and its component object identity memory were assessed in the present study. In order to disentangle these two components, an object location memory task (in which objects had to be relocated in daily environments), and a separate object identity recognition task were carried out. This study also focused on the conditions under which object locations were encoded and retrieved. Only half of the participants were aware of the fact that object locations had to be retrieved later on. Moreover, by applying the 'process dissociation procedure' to the object location memory assessments and the 'remember-know' paradigm to the object identity measure, the amount of explicit (conscious) and implicit (unconscious) retrieval was estimated for each component. In general, females performed better than males on the object location memory task. However, when controlled for object identity memory, females no longer outperformed males, whereas they did not obtain a higher general object identity memory score, nor did they have more explicit or implicit recollection of the object identities. These complicated effects might stem from a difference between males and females, in the way locations or associations between objects and locations are retrieved. In general, participants had more explicit (conscious) recollection than implicit (unconscious) recollection. No effect of encoding context was found, nor any interaction effect of gender, encoding and retrieval context.     

Memory of myself: autobiographical memory and identity in Alzheimer's disease

A number of theories posit a relationship between autobiographical memory and identity. To test this we assessed the status of autobiographical memory and identity in 20 individuals with Alzheimer's disease (AD) and 20 age-matched controls, and investigated whether degree of autobiographical memory impairment was associated with changes in identity. Two tests of autobiographical memory (Autobiographical Memory Interview, autobiographical fluency) and two measures of identity (Twenty Statements Test, identity items of the Tennessee Self Concept Scale) were administered. AD participants exhibited significant impairments on both memory tests, and changes in the strength, quality, and direction of identity relative to controls. Impairments of some components of autobiographical memory, particularly autobiographical memory for childhood and early adulthood, were related to changes in the strength and quality of identity. These findings support the critical role of early adulthood autobiographical memories (16-25 years) in identity, and suggest autobiographical memory loss affects identity.     

Memory of myself: Autobiographical memory and identity in Alzheimer's disease

A number of theories posit a relationship between autobiographical memory and identity. To test this we assessed the status of autobiographical memory and identity in 20 individuals with Alzheimer's disease (AD) and 20 age‐matched controls, and investigated whether degree of autobiographical memory impairment was associated with changes in identity. Two tests of autobiographical memory (Autobiographical Memory Interview, autobiographical fluency) and two measures of identity (Twenty Statements Test, identity items of the Tennessee Self Concept Scale) were administered. AD participants exhibited significant impairments on both memory tests, and changes in the strength, quality, and direction of identity relative to controls. Impairments of some components of autobiographical memory, particularly autobiographical memory for childhood and early adulthood, were related to changes in the strength and quality of identity. These findings support the critical role of early adulthood autobiographical memories (16–25 years) in identity, and suggest autobiographical memory loss affects identity.     

The Development of New Tests of Source Memory and a New Approach to the Testing of Equivalence of Parallel Versions

The principal aim of this study was to develop tests of source memory in both the verbal and visuo-spatial domains, which would be brief and easy to use in clinical and population settings. Source memory, that is, memory for context or attributes, is very vulnerable to the effects of ageing and to the early stages of dementia. Because longitudinal studies of cognitive function, including clinical trials, involve repeat testing, practice effects may hamper interpretation when identical tests are administered on each occasion. Accordingly, we developed parallel versions of each of the source memory tests. Rather than assuming equivalence by design, we tested the parallel versions to determine whether they were in fact equivalent in difficulty. We also explored the use of different analytic approaches to establishing equivalence. We report the results of a study in which we compared within- and between-subject performance on three parallel versions of visuo-spatial and verbal source memory tests, as well as three parallel versions of standard tests of episodic memory (word list recall) and executive function (letter fluency, category fluency, ideational fluency) in a sample of healthy elderly volunteers. Participants were tested on three occasions separated by 1 week, and test versions were counterbalanced across test sessions. We also examined performance in a group of participants tested on one occasion only, with test versions being allocated at random. We found that for a number of tests, versions which were designed to be parallel, failed to produce equivalent performance in our sample. We show how the results of this study may be of general use to researchers wishing to select particular versions of the tests in our battery. We also urge researchers to be cautious when using parallel versions of other tests. The careful matching or random allocation of items to parallel versions of a test is no guarantee that performance on the different versions will be equivalent.     

Rats know when they remember: transfer of metacognitive responding across odor-based delayed match-to-sample tests

Metamemory entails cognitively assessing the strength of one’s memories. We tested the ability of nine Long-Evans rats to distinguish between remembering and forgetting by presenting a decline option that allowed a four-choice odor-based delayed match to sample (DMTS) tests to be by-passed. Rats performed significantly better on tests they chose to take than on tests they were forced to take, indicating metacognitive responding. However, rather than control by internal mnemonic cues, one alternative explanation is that decline use is based on external test-specific cues that become associated with increased rewards overtime. To examine this possibility, we tested rats on three generalization tests in which external contingencies were inconsistent and therefore could not serve as discriminative cues. Rats transferred adaptive use of the decline response in tests that eliminated memory by presenting no sample, increased memory by presenting multiple samples, and both weakened and strengthened memory by varying the retention interval. Further, subjects chose to take or decline the test before encountering the memory test, providing evidence that rats based their metacognitive responding on internal cues rather than external ones. To our knowledge, this is the first robust evidence for metamemory in rats using the DMTS decline-test paradigm in which several possible sources of external stimulus control can be ruled out.     

Integrated memory for objects, places, and temporal order: evidence for episodic-like memory in mice

Human episodic memory refers to the recollection of an unique past experience in terms of what happened, and where and when it happened. Factoring out the issue of conscious recollection, episodic memory, even at the behavioral level, has been difficult to demonstrate in non-human mammals. Although, it was previously shown that rodents can associate what and when or what and where information given on unique trials, it proved to be difficult to demonstrate memory for what, where, and when simultaneously in mammals, without using extensive training procedures, which might induce semantic rather than episodic memory recall. Towards the goal of an animal model of human episodic memory we designed an three-trial object exploration task in which different versions of the novelty-preference paradigm were combined to subsume (a) object recognition memory, (b) the memory for locations in which objects were explored, and (c) the temporal order memory for object presented at distinct time points. We found that mice spent more time exploring two "old familiar" objects relative to two "recent familiar" objects, reflecting memory for what and when and concomitantly directed more exploration at a spatially displaced "old familiar" object relative to a stationary "old familiar" object, reflecting memory for what and where. These results suggest that during a single test trial the mice were able to (a) recognize previously explored objects, (b) remember the location in which particular objects were previously encountered, and (c) to discriminate the relative recency in which different objects were presented. According to the currently discussed behavioral criteria for episodic-like memory in animals, our results suggest that mice are capable to form such higher order memories.     

Validation of a rodent model of episodic memory

Episodic memory consists of representations of specific episodes that happened in the past. Modeling episodic memory in animals requires careful examination of alternative explanations of performance. Putative evidence of episodic-like memory may be based on encoding failure or expectations derived from well-learned semantic rules. In Experiment 1, rats were tested in a radial maze with study and test phases separated by a retention interval. The replenishment of chocolate (at its study-phase location) depended on two factors: time of day (morning vs. afternoon) and the presence or absence of chocolate pellets at the start of the test phase. Because replenishment could not be decoded until the test phase, rats were required to encode the study episode. Success in this task rules out encoding failure. In Experiment 2, two identical mazes in different rooms were used. Chocolate replenishment was trained in one room, and then they were asked to report about a recent event in a different room, where they had no expectation that the memory assessment would occur. Rats successfully answered the unexpected question, ruling out use of expectations derived from well-learned semantic rules. Our behavioral methods for modeling episodic memory may have broad application for assessments of genetic, neuroanatomical, neurochemical, and neurophysiological bases of both episodic memory and memory disorders such as those that occur in Alzheimer’s disease.     

Episodic-like memory in zebrafish

Episodic-like memory tests often aid in determining an animal’s ability to recall the what, where, and which (context) of an event. To date, this type of memory has been demonstrated in humans, wild chacma baboons, corvids (Scrub jays), humming birds, mice, rats, Yucatan minipigs, and cuttlefish. The potential for this type of memory in zebrafish remains unexplored even though they are quickly becoming an essential model organism for the study of a variety of human cognitive and mental disorders. Here we explore the episodic-like capabilities of zebrafish (Danio rerio) in a previously established mammalian memory paradigm. We demonstrate that when zebrafish were presented with a familiar object in a familiar context but a novel location within that context, they spend more time in the novel quadrant. Thus, zebrafish display episodic-like memory as they remember what object they saw, where they saw it (quadrant location), and on which occasion (yellow or blue walls) it was presented.     

Rewriting the past: some factors affecting the variability of personal memories

Three experiments assessed the variability of autobiographic memories and investigated the effects of age of the person, the age of the memory and memory characteristics. Using different paradigms to examine repeated recall of the same memories all three experiments showed that the memories of the older adults were more stable in terms of the content. The memories of the younger group showed greater variability across successive recalls. Experiment 3 also showed that the order in which older people recalled memory details was relatively consistent: younger adults showed greater variability in output order. Variability was also significantly affected by the age of the memory with older memories being less variable. No significant effects of memory characteristics (importance, emotion and frequency of rehearsal) were detected. Several explanations for these findings were considered. It was concluded that the personal memories of older people tend to be reproduced from a fixed precompiled representation whereas young people's memories are dynamically reconstructed on each occasion of recall. Copyright © 2000 John Wiley & Sons, Ltd.     

The development of explicit memory for basic perceptual features

In three experiments with 164 individuals between 4 and 80 years old, we examined age-related changes in explicit memory for three perceptual features--item identity, color, and location. In Experiments 1-2, feature recognition was assessed in an incidental learning, gamelike task resembling the game Concentration. In Experiment 3, feature recognition was assessed using a pencil-and-paper task after intentional learning instructions. The form of the explicit memory function across the life span varied with the particular perceptual feature tested and the type of task. Item recognition was excellent at all ages but was significantly poorer for older adults than children, color recognition peaked in late childhood on the gamelike task, and location recognition peaked in early adulthood on the pencil-and-paper task. These findings indicate that performance on explicit memory tests is not a consistent inverted U-shaped function of age across various features. Explicit memory performance depends on what is measured and how. Because explicit memory typically reflects a composite of different features, age-related changes in explicit memory will not necessarily correspond to the function for any single one.     

不同任务情境中的前瞻记忆是一致的吗？

对47名大学生被试依次进行自然情境中的人为任务、自然情境中的自然任务、实验室情境中的人为任务和实验室情境中的自然任务的测试。结果发现,相同任务情境中的不同性质的前瞻记忆具有一致性,特别是在自然情境中的一致性更为明显;相同任务性质但不同任务情境下的前瞻记忆没有一致性,实验室中的前瞻记忆与自然情境中的前瞻记忆不能相互预测。