The distribution of early childhood memories

The quantitative distribution of autobiographical memories for the first decade of life is described. The distribution, based on over 11,000 autobiographical memories from age 10 and younger from published studies, is nearly identical for males and females, for participants of different ages, and for different methods of collecting data, including using words to cue memories from anywhere in the lifespan or from just the childhood years, exhaustive listing of all early memories, and interviews.     

Smell your way back to childhood: Autobiographical odor memory

This study addressed age distributions and experiential qualities of autobiographical memories evoked by different sensory cues. Ninety-three older adults were presented with one of three cue types (word, picture, or odor) and were asked to relate any autobiographical event for the given cue. The main aims were to explore whether (1) the age distribution of olfactory-evoked memories differs from memories cued by words and pictures and (2) the experiential qualities of the evoked memories vary over the different cues. The results showed that autobiographical memories triggered by olfactory information were older than memories associated with verbal and visual information. Specifically, most odor-cued memories were located to the first decade of life (<10 years), whereas memories associated with verbal and visual cues peaked in early adulthood (11–20 years). Also, odor-evoked memories were associated with stronger feelings of being brought back in time and had been thought of less often than memories evoked by verbal and visual information. This pattern of findings suggests that odor-evoked memories may be different from other memory experiences. nt|mis|This work was supported by a grant from the Swedish Research Council (No. F0647/2001) to M.L.     

Modeling Individual Differences in Autobiographical Memory Distributions Using Mixed Logitnormal Regression

We introduce a model for examining individual differences in the lifespan distribution of autobiographical memories (after the exclusion of recent memories). The model is based on the logitnormal distribution, contains two submodels, one for location (average age at which autobiographical memories were encoded) and one for scale (range of ages at which autobiographical memories were encoded), allows for the inclusion of predictor variables, and includes random effects. The model was used to analyze autobiographical memories reported by 90 older participants. Results show that there were reliable individual differences in location and scale. Moreover, age, proportion of positive memories, proportion of first‐time experiences, comprehensibility, and meaningfulness accounted for 26% of individual differences in location and 23% of individual differences in scale of autobiographical memory distributions. These findings indicate that individual differences are present in autobiographical memory distributions and can, in part, be accounted for by characteristics of the memories and of the person who generated them.Copyright © 2016 John Wiley & Sons, Ltd.     

How can individual differences in autobiographical memory distributions of older adults be explained?

The reminiscence bump phenomenon has frequently been reported for the recall of autobiographical memories. The present study complements previous research by examining individual differences in the distribution of word-cued autobiographical memories. More importantly, we introduce predictor variables that might account for individual differences in the mean (location) and the standard deviation (scale) of individual memory distributions. All variables were derived from different theoretical accounts for the reminiscence bump phenomenon. We used a mixed location-scale logitnormal model, to analyse the 4602 autobiographical memories reported by 118 older participants. Results show reliable individual differences in the location and the scale. After controlling for age and gender, individual proportions of first-time experiences and individual proportions of positive memories, as well as the ratings on Openness to new Experiences and Self-Concept Clarity accounted for 29% of individual differences in location and 42% of individual differences in scale of autobiographical memory distributions. Results dovetail with a life-story account for the reminiscence bump which integrates central components of previous accounts.     

The phenomenology and temporal distributions of autobiographical memories elicited with emotional and neutral cue words

In this study we examined whether the temporal distribution of autobiographical memory changes when different types of cue words are used to elicit the memories, and how the type of cue word affects the phenomenal characteristics of the memories. A total of 76 participants, ranging in age from 21 to 69 years, were presented with 22 cue words (emotional, emotion-provoking, and neutral). They were asked to recall a personal event and to complete the Autobiographical Memory Questionnaire (Rubin, Schrauf, & Greenberg, 2003, 2004) for each cue word. Results showed that the phenomenological properties of autobiographical memories which were cued with emotional and emotion-provoking words were rated higher than those of memories which were cued with neutral words, and that the peak in the temporal distributions of the autobiographical memories that were cued with emotional or emotion-provoking words were located later than the peak of the distribution of the memories that were cued with neutral words.     

Predicting remembering and forgetting of autobiographical memories in children and adults: a 4-year prospective study

Preservation and loss to forgetting of autobiographical memories is a focus in both the adult and developmental literatures. In both, there are comparative arguments regarding rates of forgetting. Children are assumed to forget autobiographical memories more rapidly than adults, and younger children are assumed to forget more rapidly than older children. Yet few studies can directly inform these comparisons: few feature children and adults, and few prospectively track the survival of specific autobiographical memories over time. In a 4-year prospective study, we obtained autobiographical memories from children 4, 6, and 8 years, and adults. We tested recall of different subsets of the events after 1, 2, and 3 years. Accelerated rates of forgetting were apparent among all child groups relative to adults; within the child groups, 4- and 6-year-olds had accelerated forgetting relative to 8-year-olds. The differences were especially pronounced in open-ended recall. The thematic coherence of initial memory reports also was a significant predictor of the survival of specific memories. The pattern of findings is consistent with suggestions that the adult distribution of autobiographical memories is achieved as the quality of memory traces increases (here measured by thematic coherence) and the rate of forgetting decreases.     

Mental time travel after trauma: the specificity and temporal distribution of autobiographical memories and future-directed thoughts

The present study investigated the relationship between trauma exposure and specificity and temporal distribution of autobiographical memories and future-directed thoughts. A group of sexual assault victims were compared with women without previous trauma exposure in relation to specificity of autobiographical memories, as measured by the Autobiographical Memory Task (AMT) and specificity of future-directed thoughts as measured by the Future Cueing Task (FCT). The temporal distribution of future-directed thoughts and autobiographical memories was studied by asking the participants to estimate when each memory reported on the AMT had occurred and when each future event reported on the FCT would occur. The results showed no difference between the trauma group and the controls on specificity of autobiographical memories and future-directed thoughts. In line with a review of Moore and Zoellner (2007), PTSD symptoms as measured by the Impact of Event Scale (IES) correlated negatively with specificity. Furthermore, we observed no difference in temporal distribution of future-directed thoughts or autobiographical memories between trauma exposed participants and controls.     

A Study of Gender Differences in Autobiographical Memory: Broken Down by Age and Sex

Data from 40 older adults who produced autobiographical memories to word cues and to the request to list five important memories, and data from 60 older adults who answered factual multiple-choice questions for events spread across their lives, were analyzed for gender differences. In spite of considerable statistical power, there were no gender differences in the distribution of autobiographical memories over the lifespan, in the distribution of important memories, in various ratings provided to these memories, or in the distribution of knowledge for events. The only gender difference found was that men performed better on factual questions about current events and baseball. Thus, counter to what might be expected from Darwinian theory and some behavioral data, gender differences were minimal.     

Mental time travel after trauma: The specificity and temporal distribution of autobiographical memories and future-directed thoughts

The present study investigated the relationship between trauma exposure and specificity and temporal distribution of autobiographical memories and future-directed thoughts. A group of sexual assault victims were compared with women without previous trauma exposure in relation to specificity of autobiographical memories, as measured by the Autobiographical Memory Task (AMT) and specificity of future-directed thoughts as measured by the Future Cueing Task (FCT). The temporal distribution of future-directed thoughts and autobiographical memories was studied by asking the participants to estimate when each memory reported on the AMT had occurred and when each future event reported on the FCT would occur. The results showed no difference between the trauma group and the controls on specificity of autobiographical memories and future-directed thoughts. In line with a review of Moore and Zoellner (2007), PTSD symptoms as measured by the Impact of Event Scale (IES) correlated negatively with specificity. Furthermore, we observed no difference in temporal distribution of future-directed thoughts or autobiographical memories between trauma exposed participants and controls.     

Using cue words to investigate the distribution of autobiographical memories in childhood

The cue-word technique is frequently used with adults to examine the distribution of autobiographical memories across the life span. Such studies demonstrate childhood amnesia: a paucity of memories of events from the first 3(1/2) years of life, and a gradually increasing number of memories from age 3 to age 7. The pattern is remarkable in light of findings of autobiographical competence among children in the period of life eventually obscured by this amnesia. In the present study, we modified the cue-word task for use with school-age children. Seven- to 10-year-olds successfully generated and dated memories of past events. Girls provided more complete narratives than boys. Across the sample, the resulting distribution of memories was better fit by an exponential than by a power function, implying that early memories may not consolidate and instead remain vulnerable to interference. Implications for explanations of childhood amnesia are discussed.     

Emotional organization of autobiographical memory

The emotional organization of autobiographical memory was examined by determining whether emotional cues would influence autobiographical retrieval in younger and older adults. Unfamiliar musical cues that represented orthogonal combinations of positive and negative valence and high and low arousal were used. Whereas cue valence influenced the valence of the retrieved memories, cue arousal did not affect arousal ratings. However, high-arousal cues were associated with reduced response latencies. A significant bias to report positive memories was observed, especially for the older adults, but neither the distribution of memories across the life span nor response latencies varied across memories differing in valence or arousal. These data indicate that emotional information can serve as effective cues for autobiographical memories and that autobiographical memories are organized in terms of emotional valence but not emotional arousal. Thus, current theories of autobiographical memory must be expanded to include emotional valence as a primary dimension of organization.     

The reminiscence bump without memories: The distribution of imagined word-cued and important autobiographical memories in a hypothetical 70-year-old

The reminiscence bump is the disproportionate number of autobiographical memories dating from adolescence and early adulthood. It has often been ascribed to a consolidation of the mature self in the period covered by the bump. Here we stripped away factors relating to the characteristics of autobiographical memories per se, most notably factors that aid in their encoding or retention, by asking students to generate imagined word-cued and imagined ‘most important’ autobiographical memories of a hypothetical, prototypical 70-year-old of their own culture and gender. We compared the distribution of these fictional memories with the distributions of actual word-cued and most important autobiographical memories in a sample of 61–70-year-olds. We found a striking similarity between the temporal distributions of the imagined memories and the actual memories. These results suggest that the reminiscence bump is largely driven by constructive, schematic factors at retrieval, thereby challenging most existing theoretical accounts.     

Emotional intensity predicts autobiographical memory experience

College students generated autobiographical memories from distinct emotional categories that varied in valence (positive vs. negative) and intensity (high vs. low). They then rated various perceptual, cognitive, and emotional properties for each memory. The distribution of these emotional memories favored a vector model over a circumplex model. For memories of all specific emotions, intensity accounted for significantly more variance in autobiographical memory characteristics than did valence or age of the memory. In two additional experiments, we examined multiple memories of emotions of high intensity and positive or negative valence and of positive valence and high or low intensity. Intensity was a more consistent predictor of autobiographical memory properties than was valence or the age of the memory in these experiments as well. The general effects of emotion on autobiographical memory properties are due primarily to intensity differences in emotional experience, not to benefits or detriments associated with a specific valence.     

Ways of sampling voluntary and involuntary autobiographical memories in daily life

Cognitive psychologists have often equaled retrieval of personal events with voluntary recall from autobiographical memory, but more recent research shows that autobiographical memories often come to mind involuntarily—that is, with no retrieval effort. Voluntary memories have been studied in numerous laboratory experiments in response to word-prompts, whereas involuntary memories primarily have been examined in an everyday living context, using a structured diary procedure. However, it remains unclear how voluntary memories sampled in the laboratory map onto self-prompted voluntary memories in daily life. Here, we used a structured diary procedure to compare different types of voluntary autobiographical memories to their involuntary counterparts. The results replicated previous findings with regard to differences between word-prompted voluntary and involuntary memories, whereas there were fewer differences between self-prompted voluntary and involuntary memories. The findings raise the question as to what is the best way of sampling voluntary memories and the best comparison for involuntary memories.     

Dissociating veridicality, consistency, and confidence in autobiographical and event memories for the Columbia shuttle disaster

A total of 449 students were tested for their event memories and autobiographical memories of hearing about the Columbia shuttle disaster of 1st February 2003. Four different groups were tested 2, 18, 27, or 51 days after the event. All participants were then re-tested after 5 months (second session) and again after 1 year (third session) from the first interview. Dissociations between consistency and confidence and between event and autobiographical memories were found. Consistency and confidence in event memories, but not in autobiographical memories, were affected by time. In contrast, repeated testing selectively enhanced autobiographical memories, in accordance with the narrative and rehearsal hypothesis of Neisser and Harsh (1992). For event memories, veridicality was inversely correlated to consistency, which in turn was inversely correlated to confidence, and mainly based on omissions. As regards veridicality, the analyses showed an increase of false memories at long time delays. Results are discussed with reference to recent studies contrasting autobiographical and event memories.     

Dissociating veridicality,consistency, and confidence in autobiographical and event memories for the Columbia shuttle disaster

A total of 449 students were tested for their event memories and autobiographical memories of hearing about the Columbia shuttle disaster of 1st February 2003. Four different groups were tested 2, 18, 27, or 51 days after the event. All participants were then re-tested after 5 months (second session) and again after 1 year (third session) from the first interview. Dissociations between consistency and confidence and between event and autobiographical memories were found. Consistency and confidence in event memories, but not in autobiographical memories, were affected by time. In contrast, repeated testing selectively enhanced autobiographical memories, in accordance with the narrative and rehearsal hypothesis of Neisser and Harsh (1992). For event memories, veridicality was inversely correlated to consistency, which in turn was inversely correlated to confidence, and mainly based on omissions. As regards veridicality, the analyses showed an increase of false memories at long time delays. Results are discussed with reference to recent studies contrasting autobiographical and event memories.     

Self-grounding visual,auditory and olfactory autobiographical memories

Given that autobiographical memory provides a cognitive foundation for the self, we investigated the relative importance of visual, auditory and olfactory autobiographical memories for the self. Thirty subjects, with a mean age of 35.4 years, participated in a study involving a three × three within-subject design containing nine different types of autobiographical memory cues: pictures, sounds and odors presented with neutral, positive and negative valences. It was shown that visual compared to auditory and olfactory autobiographical memories involved higher cognitive and emotional constituents for the self. Furthermore, there was a trend showing positive autobiographical memories to increase their proportion to both cognitive and emotional components of the self, from olfactory to auditory to visually cued autobiographical memories; but, yielding a reverse trend for negative autobiographical memories. Finally, and independently of modality, positive affective states were shown to be more involved in autobiographical memory than negative ones.     

Islands of memory: Autobiographical remembering in amnestics

In amnestics with anterograde amnesia, memories of post-onset autobiographical experiences, if present at all, are typically barren and impoverished. However, there have been sporadic reports of islands of memory—memories that are vivid, detailed, and specific to time and place. The aim of this study was to verify the presence of such memories and examine their incidence rate. Anterograde amnestics were interviewed in their home using a narrative interviewing strategy with a view to describing memory in everyday life. Each autobiographical memory of a post-onset event was coded for quantity-length, and quality-episodicity. In just over half of the amnestics (8 out of 14), a memory that was lengthy, rich in personal details, and localisable was recollected. The quantitative and qualitative aspects of these island memories were significantly different from the other autobiographical memories that the amnestics supplied. These memories were at odds with what would be expected on the basis of their performance on standardised memory instruments. Our findings suggest there is occasionally more variability in remembering of autobiographical experiences in some amnestics than has traditionally been believed.     

Islands of memory: Autobiographical remembering in amnestics

In amnestics with anterograde amnesia, memories of post-onset autobiographical experiences, if present at all, are typically barren and impoverished. However, there have been sporadic reports of islands of memory--memories that are vivid, detailed, and specific to time and place. The aim of this study was to verify the presence of such memories and examine their incidence rate. Anterograde amnestics were interviewed in their home using a narrative interviewing strategy with a view to describing memory in everyday life. Each autobiographical memory of a post-onset event was coded for quantity-length, and quality-episodicity. In just over half of the amnestics (8 out of 14), a memory that was lengthy, rich in personal details, and localisable was recollected. The quantitative and qualitative aspects of these island memories were significantly different from the other autobiographical memories that the amnestics supplied. These memories were at odds with what would be expected on the basis of their performance on standardised memory instruments. Our findings suggest there is occasionally more variability in remembering of autobiographical experiences in some amnestics than has traditionally been believed.