Time scale similarity and long-term memory for autobiographical events

We examine the extent to which retrieval from very long-term autobiographical memory is similar when participants are asked to retrieve from widely differing periods of time. Three groups of 20 participants were given 4 min to recall autobiographical events from the last 5 weeks, 5 months, or 5 years. Following recall, the participants dated their events. Similar retrieval rates, relative recency effects, and relative lag-recency effects were found, despite the fact that the considered time scales varied by a factor of 52. These data are broadly consistent with the principle of recency, the principle of contiguity (Howard & Kahana, 2002), and scale similarity in the rates of recall (Brown, Neath, & Chater, 2007; Maylor, Chater, & Brown, 2001). These findings are taken as support for models of memory that predict time scale similarity in retrieval, such as SIMPLE (Brown et al., 2007) and TCM (Howard & Kahana, 2002).     

Gender differences in autobiographical memory for childhood emotional experiences

Research to date has paid remarkably little heed to gender differences in autobiographical memory. To redress this, the author examined memory for childhood events in adult men and women remembering back to childhood, and in children themselves. Five studies were conducted, and results revealed that females consistently recalled more childhood memories than males did and were generally faster in accessing the memories recalled. Furthermore, the gender difference observed was specific to memories of events associated with emotion and was apparent across a diverse range of emotions experienced by both the self and others. The overall pattern of findings obtained is consistent with the proposition that gender-differentiated socialization processes influence the content and complexity of representations of autobiographical emotional events in memory. To some extent, then, autobiographical memory appears to be a socially constructed phenomenon.     

Eye fixations and memory for emotional events.

Subjects watched either an emotional, neutral, or unusual sequence of slides containing 1 critical slide in the middle. Experiments 1 and 2 allowed only a single eye fixation on the critical slide by presenting it for 180 ms (Experiment 1) or 150 ms (Experiment 2). Despite this constraint, memory for a central detail was better for the emotional condition. In Experiment 3, subjects were allowed 2.70 s to view the critical slide while their eye movements were monitored. When subjects who had devoted the same number of fixations were compared, memory for the central detail of the emotional slide was again better. The results suggest that enhanced memory for detail information of an emotional event does not occur solely because more attention is devoted to the emotional information.     

Affective orientation influences memory for emotional and neutral words

Memory is better for emotional words than for neutral words, but the conditions contributing to emotional memory improvement are not entirely understood. Elsewhere, it has been observed that retrieval of a word is easier when its attributes are congruent with a property assessed during an earlier judgment task. The present study examined whether affective assessment of a word matters to its remembrance. Two experiments were run, one in which only valence assessment was performed, and another in which valence assessment was combined with a running recognition for list words. In both experiments, some participants judged whether each word in a randomized list was negative (negative monitoring), and others judged whether each was positive (positive monitoring). We then tested their explicit memory for the words via both free recall and delayed recognition. Both experiments revealed an affective congruence effect, such that negative words were more likely to be recalled and recognized after negative monitoring, whereas positive words likewise benefited from positive monitoring. Memory for neutral words was better after negative monitoring than positive monitoring.Thus, memory for both emotional and neutral words is contingent on one's affective orientation during encoding.     

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.     

Overgeneral autobiographical memory and traumatic events: an evaluative review

Does trauma exposure impair retrieval of autobiographical memories? Many theorists have suggested that the reduced ability to access specific memories of life events, termed overgenerality, is a protective mechanism helping attenuate painful emotions associated with trauma. The authors addressed this question by reviewing 24 studies that assessed trauma exposure and overgenerality, examining samples with posttraumatic stress disorder, acute stress disorder, depression, traumatic event exposure, and other clinical disorders. Limitations are discussed, including variations in assessment of events, depression, and overgenerality and the need for additional comparison groups. Across studies, there was no consistent association between trauma exposure and overgenerality, suggesting that trauma exposure is unlikely to be the primary mechanism leading to overgenerality. Instead, psychopathology factors such as depression and posttraumatic stress appear to be more consistently associated with overgenerality. Alternative overgenerality theories may help identify key overgenerality mechanisms, improving current understanding of autobiographical memory processes underlying psychopathology.     

The influence of cognitive and emotional suppression on overgeneral autobiographical memory retrieval

Over-general autobiographical memory (OAM) retrieval is characterized by retrieval of categoric autobiographical memories. According to the CarFAX model, this tendency may result from avoidance which functions to protect the person against recalling details of upsetting memories. This study tested whether avoidance strategies impact on the ability to retrieve specific autobiographical memories. Healthy participants (N = 51) watched a negative video clip and were instructed to either suppress any thought (thought suppression), suppress any feeling (emotional inhibition), or think and feel naturally (controls) in response to the video. Participants then completed the Autobiographical Memory Test. Participants engaging in either thought suppression or emotional inhibition retrieved fewer categoric autobiographical memories than controls. These findings challenge the affect regulation component of the CarFAX model insofar as they suggest that regulatory strategies that aim to reduce awareness of adverse emotional memories do not necessarily lead to increased recall of categoric autobiographical memories.     

Autobiographical memory for stressful events: the role of autobiographical memory in posttraumatic stress disorder

To provide the three-way comparisons needed to test existing theories, we compared (1) most-stressful memories to other memories and (2) involuntary to voluntary memories (3) in 75 community dwelling adults with and 42 without a current diagnosis of posttraumatic stress disorder (PTSD). Each rated their three most-stressful, three most-positive, seven most-important and 15 word-cued autobiographical memories, and completed tests of personality and mood. Involuntary memories were then recorded and rated as they occurred for 2 weeks. Standard mechanisms of cognition and affect applied to extreme events accounted for the properties of stressful memories. Involuntary memories had greater emotional intensity than voluntary memories, but were not more frequently related to traumatic events. The emotional intensity, rehearsal, and centrality to the life story of both voluntary and involuntary memories, rather than incoherence of voluntary traumatic memories and enhanced availability of involuntary traumatic memories, were the properties of autobiographical memories associated with PTSD.     

Sex-related impairment of memory for emotional events with beta-adrenergic blockade

On the basis of recent evidence indicating a sex-related lateralization of amygdala function in memory for emotional events, together with substantial evidence suggesting hemispheric specialization in processing global (central) versus local (detail) aspects of a situation, and the established dependence of the amygdala's memory modulating function on beta-adrenergic receptor activation, we predicted differential effects of a beta-adrenergic receptor antagonist (propranolol) on long-term memory for an emotionally arousing story in men and women. Specifically, we predicted that, relative to placebo, propranolol would impair memory for information central to the story line, but not memory for peripheral story details in men. Conversely, propranolol would impair memory for peripheral details, but not for central information in women. Here we confirm this prediction with a novel analysis of data from our two published studies of propranolol's effect on memory for an emotionally arousing story. These findings demonstrate a sex-related impairment of memory for emotional information by beta-adrenergic blockade. Additionally, they provide support for the hypothesis that, in this paradigm, emotional arousal enhances long-term memory for central information in men via activation of right amygdala/hemisphere function, and enhances long-term memory for peripheral details in women via activation of left amygdala/hemisphere function.     

Separating past and future autobiographical events in memory: Evidence for a reality monitoring asymmetry

After thinking about the past and imagining the future, how do people separate these real and imagined events in memory? We had subjects engage in past and future autobiographical elaboration, then later take memory tests that required them to recollect these earlier generated events. In Experiment 1, testing memory for previously generated past or future autobiographical events led to fewer source memory confusions than did an elaborative control task, suggesting that the distinctive features of autobiographical elaboration improved subsequent retrieval monitoring accuracy. In Experiment 2, we directly compared retrieval monitoring accuracy for previously generated past and future autobiographical events and found that subjects made fewer source confusions when searching memory for future events. This asymmetry suggests that the features characterizing future elaborations (e.g., cognitive operations) were used more effectively during reality monitoring than were the features characterizing past elaborations (e.g., perceptual details), and has implications for future-oriented theories of memory.     

Sampling autobiographical memory

An empirical procedure for probing autobiographical memory was assessed. Words designating common objects, activities, and feelings were used as guides for recall of discrete experiences. Four properties of the recollections were assessed: latency, age of occurrence, temporal specificity of memory report, and type of experience. The three results of most general interest were: (1) consistent differences in properties of reports elicited by affect terms and those elicited by object and activity words; (2) a curvilinear relationship between latency and event age; and (3) reliable sex differences. Several proposals regarding the organization of autobiographical memory, and voluntary recall of personal experiences are discussed.     

Remote memory: recalling autobiographical and public events from across the lifespan.

In this study the recall of autobiographical and public events across the lifespan was examined in a sample of middle-aged and older-aged adults. The tasks were modified versions of one first introduced by Galton (1879), and they required subjects to recall events from specific time periods across their entire lifespan. The four tasks differed in the nature of the episodes requested (autobiographical or public) and whether recall was word-cued or non-word-cued. Verification of public events was assessed archivally, and autobiographical events were verified by a sample of relatives for a subgroup of the subjects and reported events. The results indicated that memory for public events decreases with increased age of the subject, but this effect is not generally found for the recall of autobiographical events. The older-aged subjects were able to recall an equal number of autobiographical episodes from all life segments, whereas recall of news events tended to decrease with remoteness of the episode. These data are contrary to those models that posit general memory loss as a function of age or of remoteness of the events.     

Recall of autobiographical events

The clarity with which events that happened 6 years earlier can be recalled was estimated. The estimates are consistent with a gradual degradation rather than a precipitate decline of memory, and with the proposition that once an event cannot be recalled then it will remain inaccessible under similar conditions of cueing. Rare events are recalled well, suggesting that proactive interference has a strong influence on difficulty to recall. Vivid events are recalled well, also, but other dimensions such as importance of the event, its association with semantic knowledge, and the intensity of physical sensation are not related to recallability. Memory for the date of an event is poor, but for its time of day is good.     

Rumination and overgeneral autobiographical memory

Two studies investigated the effects of rumination on the retrieval of autobiographical memories in high-depressed and low-depressed individuals. Experiment 1 administered either a rumination or distraction task prior to a cued autobiographical memory task. High-depressed participants recalled more overgeneral memories following rumination relative to distraction, whereas experimental inductions did not influence low-depressed participants. Experiment 2 administered either a positive or negative rumination task prior to a cued autobiographical memory task. Negatively valenced rumination led high-depressed participants to recall more overgeneral memories than positively valenced rumination; this effect was not observed in low-depressed participants. These findings accord with the proposal that rumination is a mediating mechanism in the retrieval of overgeneral memories, and extends this proposal by indicating that negatively valenced ruminative content is particularly instrumental in inducing overgeneral retrieval.     

Ruminative self-focus and autobiographical memory

Many studies have shown a positive relationship between elevated dispositional self-focus and emotional disorder. Trapnell and Campbell (1999) proposed that this relationship was only true for ruminative forms of self-focus, reflective self-focus being associated with psychological health. The present study aimed: (1) to examine the replicability of Trapnell and Campbell's (1999) questionnaire-based differentiation of reflective and ruminative dispositional self-focus; (2) to see whether reflection and rumination could also be differentiated using measures of autobiographical memory; (3) to see whether such memory measures could elucidate mechanisms underlying different forms of dispositional self-focus. 130 volunteers retrieved autobiographical memories to neutral cue words and completed questionnaires. Questionnaires differentiated reflection and rumination: reflection correlated with openness to experience, whereas rumination correlated with neuroticism, replicating previous findings that it is specifically ruminative self-focus that is maladaptive. Memory measures also differentiated reflection and rumination: reflection was unrelated to the affective qualities of memories, whereas rumination correlated with measures of the happiness, unhappiness and at-oneness of memories. Dispositional ruminative self-focus, like neuroticism, was specifically related to increased accessibility of memories of events where individuals felt “not at all at-one with things”. This style of memory access could underpin dispositional ruminative self-focus, which is closely linked to neuroticism.     

When autobiographical memory begins

The authors review competing theories concerning the emergence and early development of autobiographical memory. It is argued that the differences between these accounts, although important, may be more apparent than real. The crux of these disagreements lies not in what processes are important, but rather, the role these different processes play in the emergence of autobiographical memory and the temporal primacy of these controlling variables. These differences are explored theoretically and then extant as well as new data are brought to bear on these issues. What emerges is a new, more inclusive, multifactorial framework that integrates the controlling variables from diverse perspectives providing a more complete account of the beginnings of autobiographical memory.     

Organization in autobiographical memory

Three experiments investigated timed autobiographical memory retrieval to cue words and phrases. In the first experiment, subjects retrieved memories to cues that named semantic category members and were primed with the superordinate category name or with a neutral word. No prime effects were observed. In the second experiment, subjects retrieved memories to primed and unprimed semantic category cues and to personal primes and personal history cues. Personal primes named lifetime periods (e.g., “school days”) and personal history cues named general events occurring in those lifetime periods for each subject (e.g., “holiday in Italy”). Only personal primes were found to significantly facilitate memory retrieval. A third experiment replicated this finding and also failed to find any prime effects to primes and cues naming activities not directly related to an individual’s personal history. In this experiment, characteristics of recalled events (e.g,, personal importance, frequency of rehearsal, pleasantness, and specificity of the memory) were found to be strongly associated with memories retrieved to personal cues and only mildly associated with memories retrieved to other types of cues. These findings suggest that one way in which autobiographical memories may be organized is in terms of a hierarchically structured abstracted personal history.     

Regret as autobiographical memory

We apply an autobiographical memory framework to the study of regret. Focusing on the distinction between regrets for specific and general events we argue that the temporal profile of regret, usually explained in terms of the action–inaction distinction, is predicted by models of autobiographical memory. In two studies involving participants in their sixties we demonstrate a reminiscence bump for general, but not for specific regrets. Recent regrets were more likely to be specific than general in nature. Coding regrets as actions/inactions revealed that general regrets were significantly more likely to be due to inaction while specific regrets were as likely to be due to action as to inaction. In Study 2 we also generalised all of these findings to a group of participants in their 40s. We re-interpret existing accounts of the temporal profile of regret within the autobiographical memory framework, and outline the practical and theoretical advantages of our memory-based distinction over traditional decision-making approaches to the study of regret.     

The impact of stress on neutral and emotional aspects of episodic memory

The present experiment demonstrates that exposure to a significant psychological stressor (administered before watching a slide show) preserves or even enhances memory for emotional aspects of an event, and simultaneously disrupts memory for non-emotional aspects of the same event. Stress exposure also disrupted memory for information that was visually and thematically central to the event depicted in the slide show. Memory for peripheral information, on the other hand, was unaffected by stress. These results are consistent with theories invoking differential effects of stress on brain systems responsible for encoding and retrieving emotional memories (the amygdala) and non-emotional memories (e.g., the hippocampal formation), and inconsistent with the view that memories formed under high levels of stress are qualitatively the same as those formed under ordinary emotional circumstances. These data, which are also consistent with results obtained in a number of studies using animals and humans, have implications for the traumatic memory debate and theories regarding human memory.