Memory for unique personal events: The roommate study

Memory for naturally occurring episodic events was measured along with memory for the date of occurrence of those events. The effect of rehearsal was also measured. Participants in the experiment recorded unique personal events for themselves and their roommates for a semester (data were collected for approximately 14 weeks). They also rated the memorability of the events at the time the events were recorded. The roommates were unaware that they were to be tested on the events until approximately I week before the memory test. Accuracy in dating events decreased at the rate of roughly 1 day every week of the retention interval. Events rated as memorable were encoded better than events rated as unmemorable but were forgotten at the same rate. Increasing rehearsal decreased the rate of forgetting the events. Although the recorders selected the events to be recorded and knew they were to be tested on those events, they did not differ from their roommates on any of the memory measures     

Memory for traumatic events

This research compares memory for traumatic events with memory for non-traumatic versions of the same event. In Experiment 1, subjects watched an event depicted in slides while focusing and rehearsing the central detail of each slide. They were tested after a short or a longer retention interval (20 min or 2 weeks). Subjects who watched the traumatic version were better able to recall the central details that they had rehearsed, but were less well able to recognize the specific slides that they saw. Better recall for the traumatic group did not occur because the words used to describe the recalled details were inherently more memorable, as shown in Experiment 2. In Experiment 3, subjects watched either a traumatic or non-traumatic version of a filmed event and about 6 months later they were asked to remember the essence of the film. Subjects who saw the traumatic version were better able to recall the essence of the film. A similar finding was obtained with a group of subjects from Experiment 1 who were also contacted about 6 months after their initial participation. These results suggest that some information (the essence, the theme) of a traumatic event might be relatively well retained in memory, while memory is impaired for many of the specific, and especially peripheral, details.     

Memory for thematically arousing events

Many studies have indicated that emotional arousal improves memory for the center, or gist, of an event but undermines memory for the event's periphery. However, all of these studies have elicited emotion by showing participants some salient visual stimulus intended to arouse them (e.g., the sight of a wound). This stimulus may have served as an attention magnet, and this, not the arousal, may have been the cause of the observed narrowing of memory. In this article, we examine how participants remember events that involve thematically induced arousal, arousal produced by empathy, rather than by a visual emotional stimulus. The data show that emotionality improves memory for all aspects of these events, with no memory narrowing.     

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.     

Memory for action events: findings in neurological patients

Encoding action phrases by enacting leads normally to better memory performance than verbal encoding. In order to gain additional insight into the representational basis of the enactment effect, neurological patients are contrasted with healthy participants. Persons suffering from Parkinson's disease, which primarily impairs the motor system, and patients suffering from Frontal Lobe Syndrome, which primarily affects action-related planning processes, were involved. We investigated whether the enactment effect would be differentially affected by these disorders. In addition, the characteristics of information processing after encoding by enacting was analyzed by varying memory material (unrelated versus clusterable actions) and by adding an encoding condition that included obligatory action planning (director condition). The findings indicate that the impact of motor information for the enactment effect is not dominant compared to the role of action-related cognitive and motivational processes, in particular planning processes. The findings of the two experiments are explained within traditional conceptual memory theories.     

Memory for events after twenty years

This is a study of one person's memory for events that occurred twenty years earlier. Memory was observed to follow an asymptotic rate of decay. No experience of recovered memories occurred. Factors found to be related to recall were the rarity of the event, its vividness, and the emotional intensity experienced at the time. Factors unrelated or only weakly related were perceived importance of the event, its association with knowledge, and intensities of physical sensations. Pleasant events were recalled a little better than unpleasant. Though less strongly associated with memory than is location, moderate marking of events with date and time was found. The results suggest that personal memory declines as the images of events one by one submerge into the mass of generalized experiences. The more vivid, rare, and emotional experiences are more likely to remain discriminable, and may be sustained by rehearsal. Copyright © 2002 John Wiley & Sons, Ltd.     

Memory for unattended events: Remembering with and without awareness

The effects of memory for unattended events—for example, events that occur while a person is asleep, anesthetized, or selectively attending to other ongoing events, as in a speech-shadowing task—are rarely revealed in tests of retention that require remembering to be deliberate or intentional. Might such effects become evident in tests that do not demand awareness of remembering? Results of the present shadowing study, involving the recognition and spelling of previously unattended homophones, suggest an affirmative answer to this question.     

When personal history repeats itself: Decomposing memories for recurring events

Retrospective reports of personal events constitute the principal data source for much applied social science research. Such reports are known to be subject to biases and errors of inference. In health surveys, for example, events associated with chronic conditions are particularly likely to be under-reported (Jabine, 1987). In this series of studies we apply perspectives and tools from psychological studies of memory to the problem of understanding and improving reports of past untilization of health care. In two studies we found that subjects report using different strategies to answer questions about how often they have seen a doctor over the past 12 months, depending on the type of doctor's visit and its frequency. A third study, in which subjects' recall was checked against medical records, provided evidence that individual health events within a group of recurring, similar events are much less likely than non-recurring events to be recalled. In Experiment 4 we tested the efficacy of cognitively oriented intervention techniques designed to (1) help subjects decompose their molar memories of groups of similar events into individual events and (2) place all remembered health events into a personal timeline. The intervention more than doubled the proportion of recurring events on the medical record that was recalled. In addition, the proportion of events that could be dated, and the accuracy of dates provided, both rose.     

Effects of context in judgments of sweetness and pleasantness

Dramatic effects of the immediate stimulus context were demonstrated for ratings of sweetness and also for ratings of pleasantness of soft drinks containing different concentrations of sucrose. The same drinks were rated sweeter when the lower concentrations were presented more frequently, less sweet when the higher concentrations were presented more frequently. A quasi-normal distribution of frequencies yielded ratings falling between the two skewed distributions. Ratings of sweetness were accurately predicted by Parducci’s (1974) range-frequency model of judgment, which was originally developed to explain contextual effects in other psychophysical dimensions. Ratings of pleasantness were also affected by context; the highest ratings were assigned to concentrations of intermediate sweetness in their respective contexts.     

Memory conjunction errors for autobiographical events: More than just familiarity

Two diary studies investigated the prevalence of memory conjunction errors for real‐life events. In both studies, participants completed detailed diary pages over the course of several weeks. Participants in both diary studies committed memory conjunction errors on a later recognition memory test. In the second diary study participants also made remember/know judgements. For a large proportion of their memory conjunction errors participants indicated that they “remembered” the event occurring in that context. These diary studies demonstrate that memory conjunction errors do occur for autobiographical memories, and these errors can seem compelling.     

Memory conjunction errors for autobiographical events: more than just familiarity

Two diary studies investigated the prevalence of memory conjunction errors for real-life events. In both studies, participants completed detailed diary pages over the course of several weeks. Participants in both diary studies committed memory conjunction errors on a later recognition memory test. In the second diary study participants also made remember/know judgements. For a large proportion of their memory conjunction errors participants indicated that they "remembered" the event occurring in that context. These diary studies demonstrate that memory conjunction errors do occur for autobiographical memories, and these errors can seem compelling.     

Memory and mineness in personal identity

Stanley Klein and Shaun Nichols (2012) describe the case of patient R.B., whose memories (they claim) lacked the sense of “mineness” usually conveyed by memory. Klein and Nichols take R.B.’s case to show that the sense of mineness is merely a contingent feature of memory, which they see as raising two problems for memory-based accounts of personal identity. First, they see it as potentially undermining the appeal of memory-based accounts. Second, they take it to show that the conception of quasi-memory that underpins many memory-based accounts is inadequate. I argue that Klein and Nichols’ characterization of R.B.’s experience is implausible; as a result, the problems that they describe for memory-based accounts of personal identity do not arise.     

Memory for action events in the bottlenosed dolphin

We investigated whether a bottlenosed dolphin’s ability to recall and repeat actions on command would immediately generalize to actions performed with specified objects. The dolphin was tested on her ability to repeat 18 novel behaviors performed with potentially interchangeable objects specified using an artificial gestural language. Such “action events” were correctly repeated at above chance levels, indicating that the dolphin had access to memories of those events. Performance levels were, however, lower than in previous tests. The dolphin appeared to have difficulty recalling which object an action was performed with. Previous research has demonstrated that animals can recall features of their environment and features of their actions independently of one another. The results of this study demonstrate (1) that the dolphin’s concept of repeating extends beyond simply accessing memories of movement patterns, and (2) that dolphins’ memories of past events incorporate representations of both self-performed acts and objects, locations, or gestural instructions. Received:10 October 1998 / Accepted after revision: 22 December 1998     

Childhood remembered: Reports of both unique and repeated events

To explore the significance of repeated memories for individuals' personal histories, we compared the characteristics of young adults' unique and repeated memories of childhood experiences. Memory type (unique vs. repeated) was a within-participant variable. In Experiment 1, college-age participants generated as many early memories as possible in 4 minutes; in Experiment 2, another sample provided complete reports of five early memories in each condition. In both experiments, participants rated the vividness, biographical importance and personal meaning of each memory and labelled the accompanying emotion. Unique memories were more vivid than repeated memories as well as more likely to include negative emotion, regardless of the method of reporting. Most importantly, college students rated their memories for unique and repeated events as equivalently infused with personal meaning. Analysis of the content of the memories reported in Experiment 2 established that unique and repeated memories did not differ in word count or percentages of perceptual terms or words indicating positive affect, although unique memories contained a greater percentage of negative affect. Additional analyses of content provided evidence for differences in the functions served by unique and repeated memories. The results have implications for the study of autobiographical memory and for identifying over-general memories.     

Memory for lists of spatial events in the rat

Three experiments are reported in which rats were presented with lists of spatial events or responses in distinct visual contexts, and retention subsequently was measured for the events occuring at each serial position. In Experiments 1 and 2, lists contained different numbers of forced choices on successively presented T-mazes, and memory for each serial position was tested on each trial. In Experiment 3, lists were made up of different numbers of forced entries into randomly ordered arms on the eight-arm radial maze, and memory for one serial position was probed on each trial. All three experiments yielded serial position curves which demonstrated recency effects but no primacy effects. Comparisons of retention for different list lengths within each experiment indicated that retention of shorter lists was equivalent to retention of the final items of longer lists and superior to retention of the initial items on longer lists. This pattern of results indicated that there was no evidence of proactive inhibition in the serial position curves. Analysis of input and output interference effects and the results of control tests suggested that both retroactive inhibition and time-based forgetting processes were responsible for recency effects.