Source monitoring in eyewitness memory: Implicit associations,suggestions, and episodic traces

Both the distinctiveness heuristic and discrepancy detection hypotheses were investigated by independently manipulating both schema consistency and incidental suggestion in an eyewitness memory paradigm. A sequence of slides was shown, followed by a postevent questionnaire that contained both schema-typical and schema-atypical information. Fifteen minutes later, a source-monitoring task was administered. In Experiment 1, the proportion of source misattribution errors was greater for schema-typical items than for schema-atypical items, and the proportion of errors on suggested items was greater than that on control items. Suggestion affected schema-typical and schema-atypical items equally, providing no support for the predictions of either hypothesis. In Experiment 2, the interval between the questionnaire and the source test was manipulated. The results of Experiment 1 were replicated under the short delay, whereas the proportion of errors increased under the long delay. An associative network model involving two types of episodic traces was used to account for the results.     

A Place for Every Event and Every Event in Its Place: Memory for Locations and Activities by 4-Year-Old Children

Episodic memories are of specific events and experiences associated with particular times and places. Whereas memory for the temporal aspects of past events has been a focus of research attention, memory for the location in which events were experienced has been less fully investigated. The limited developmental research suggests that preschool-age children, in particular, may have difficulty remembering the location in which they experienced specific events. In 2 experiments, 4-year-old children engaged in 4 unique activities in 4 unique locations in and around a laboratory suite. In Experiment 1, the children had high levels of recall of the activities, the locations, and the conjunctions of activities and locations, implying that they had formed memory representations that featured activities bound in locations. In Experiment 2, we tested whether 1 element of the bound representation—the location of an activity—served as a reliable cue to recall of the other element—the activity itself. The test was positive, providing further evidence that 4-year-old children form mnemonic conjunctions of activities and locations. The results imply that important elements of episodic memory are available to young children.     

Priming autobiographical memories: How recalling the past may affect everyday forms of autobiographical remembering

This study investigated the idea that when one recalls past episodes, that the content of those memories will activate additional episodic memories with like content, and such memories will then have the potential of surfacing in subsequent acts of involuntary and voluntary recall. We tested the episodic content priming hypothesis in two experiments. In Experiment 1, priming group participants first recalled memories about specific activities or events and then they were subsequently engaged in a word-cue voluntary autobiographical memory task. The results showed that priming group participants produced more episodic memories involving the primed content on this task than control participants occupied in the same task. In Experiment 2, episodic content priming was further tested on a measure of involuntary autobiographical memory (i.e., the vigilance task). The results on this task also revealed support for the episodic content priming hypothesis, including after a delay of 24 h.     

Changes in reality monitoring and episodic memory in early childhood

The purposes of this research were to examine the developmental relation between reality monitoring and episodic memory, to link reality monitoring to autobiographical memory by using extended naturalistic events, and to examine prefrontal functioning as a potential contributor to development in reality monitoring and episodic memory. In Experiment 1, 4-year-olds were worse than 6- or 8-year-olds at reality monitoring after a week delay, despite the fact that they remembered more about real than imagined events and remembered different aspects of each. In Experiments 2 and 3, reality monitoring and episodic memory were evaluated for 4- and 6-year-olds immediately after the events occurred and, in Experiment 3, again after a week delay. Reality monitoring was at higher levels for both age groups, but age differences remained. These data suggest that preschoolers' difficulties with reality monitoring result from a combination of episodic memory deficits and strategic differences. In addition, correlation analyses more directly linked preschoolers' reality monitoring to episodic memory and supported the hypothesis that episodic memory development is related to prefrontal functioning.     

Memory fragments as components of autobiographical knowledge

Adults described and dated two kinds of personal remembrances: a fragment—a memory moment that is largely bereft of context—and an episodic, personal event memory—a narrative that consists of a number of related events. In Experiment 1 subjects reported memories from when they were 0–8 years of age and in Experiment 2, from when they were 0–16 years of age. Fragments were judged to be older than event memories, especially in Experiment 2 where the estimated ages of most fragments were from 0 to 8 years and of most episodic memories, from 8 to 16 years. Ratings of various features of the two kinds of memories also differed. We conclude that isolated memory moments possess validity and that although they are most likely to arise when the autobiographical memory system is not fully developed, they can also originate during a time when it is. Copyright © 2006 John Wiley & Sons, Ltd.     

Selective postevent review and children's memory for nonreviewed materials

Two experiments investigated the impact of selective postevent questioning on children's memory for nonreviewed materials. In both experiments, children participated in a series of novel activities. Children in the selective-review condition were subsequently questioned about half of these and comparisons were made to memory in a no-review condition. In Experiment 1, participants were 60 5- and 9-year-olds. For children in both age groups, memory for nonreviewed activities was impaired 20 min later in free recall. In Experiment 2, participants were 60 5-year-olds. Memory impairment was found following a 1-day delay after spaced review (three sessions over 3 days) but not after massed review (three sessions on 1 day). In both experiments, memory impairment was absent when specific retrieval cues were provided. The possible mechanisms underlying these findings and their potential practical implications are discussed.     

Rumor mongering and remembering: how rumors originating in children's inferences can affect memory

This study examined how rumors originating in 3- to 6-year-olds' causal inferences can affect their own and their peers' memories for a personally experienced event. This was accomplished by exposing some members of classrooms to contextual clues that were designed to induce inferences about the causes of two unresolved components of the event. After a 1-week delay, a substantial number of children who were exposed to the clues misremembered their inferences as actual experiences. Causal inferential memory errors were most pronounced among 5- and 6-year-olds. Also, many of the children whose classmates were exposed to the clues mistakenly incorporated their classmates' causal inferences into their own accounts, with 3- and 4-year-olds being most likely to make this error.     

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.     

The susceptibility of young preschoolers to source similarity effects: Confusing story or video events with reality

This study examined children’s tendency to confuse events that varied in source similarity, which was manipulated using different media of event presentation. In Experiment 1, children in two age groups (3- and 4-year-olds and 5- and 6-year-olds) experienced a live presentation of an event, and another event was either heard from a story (low similarity group) or seen on a video (high similarity group). Immediately afterward, the children were asked to monitor the source of the events. The children in the low similarity group produced higher source discrimination scores than did the children in the high similarity group. Overall, the older children were better at source monitoring than were the younger children. In Experiment 2, the procedure was replicated except that the children’s source monitoring was tested after a 4-day delay. When attributing the source of the story or video events, both 3- and 4-year-olds and 5- and 6-year-olds in the low similarity group produced more accurate story or video attributions than did their age mates in the high similarity group. However, when attributing the source of the live events, only the 3- and 4-year-olds evidenced this effect of source similarity. The 5- and 6-year-olds in both the low and high similarity groups performed at ceiling levels for live discriminations.     

The effect of burn injury on adolescents autobiographical memory

Autobiographical memory recall was investigated in two female adolescent groups; one group who had experienced a burn injury and a matched control group. The Burn group was not currently depressed or anxious, but scored significantly higher on the intrusion subscale of the impact of event scale compared to controls. Two autobiographical memory tasks, the autobiographical memory cueing task and the Children's Autobiographical Memory Inventory (CAMI), were used. For the cueing task, the Burn group was significantly slower to recall specific memories. This group also recalled significantly fewer specific memories and significantly more extended overgeneral memories. For the CAMI, the burns group produced significantly lower semantic and episodic recall. The Burn group also produced significant correlations between sub-scales of the impact of event scale and selected measures on the autobiographical memory tasks. Higher intrusion scores were associated with less detailed episodic recall. Higher avoidance scores were associated with longer latencies to recall memories to negative cue words and fewer specific memories to all cue words. These results are discussed from the perspective that the Burn group experienced intrusive thoughts which interfered with normal autobiographical functioning.     

Social processes affecting the mnemonic consequences of rumors on children’s memory

This research examined whether the impact of overheard rumors on children’s memory for their experiences varies as a function of social processes. The results of two experiments revealed that the very same errant rumor had different consequences for children’s recollections depending on the degree and type of social interactions they had with peers after exposure to the rumor. In both experiments, 3- to 5-year-olds overheard a false rumor about a recently experienced event and then were interviewed about the event 1 week later. In Experiment 1, children were more likely to report experiencing rumored-but-nonoccurring information if they were allowed to interact naturally with peers following exposure to the rumor than if they were prevented from peer exchange. In Experiment 2, exposure to the rumor induced greater memory contamination if it was planted among familiar peers than if it was encountered among strangers.     

First words and first memories

In two experiments autobiographical memories from childhood were recalled to cue words naming common objects, locations, activities and emotions. Participants recalled their earliest specific memory associated with each word and dated their age at the time of the remembered event. A striking and specific finding emerged: age of earliest memory was systematically later, by several months, than the age of acquisition of the word to which it was associated. This was the case for earlier and later acquired words, for all word types, and for younger as well as older adults. It is suggested that this systematic lag reflects the formation of conceptual knowledge that is abstracted from details represented in early episodic memories. It is not until such knowledge is formed that a word cue and the conceptual knowledge in long-term to which it corresponds, can be used to access specific episodic memories. The implications of this for understanding childhood amnesia and for theories of the development of autobiographical memory are considered.     

The Constituent Structure of Subjective Memory Questionnaires: Evidence from Multiple Sclerosis

Making repetitive saccadic eye movements has been found to increase subsequent episodic memory retrieval and also to increase subsequent top-down attentional control. We theorise that these effects are related such that saccade-induced changes in attentional processing facilitate memory retrieval. We tested this idea by examining the effect of saccade execution on retrieval conditions that differed in relative ease of consciously accessing episodic memories. Based on recent theories of episodic retrieval, we reasoned that there is a larger role for top-down attention when memories are more difficult to access. Consequently, we expected saccade execution to have a greater facilitative effect on retrieval when memories were more difficult to access. We obtained the expected result in a recall procedure in Experiment 1 and in a recognition procedure in Experiment 2. We also examined an individual difference factor—consistency of handedness—as a possible moderator of saccade execution effects on retrieval. We discuss how our top-down attentional control hypothesis can be extended to explain beneficial effects of saccade execution on other types of cognition, as well as negative effects on retrieval in some cases.     

Are children’s memory illusions created differently from those of adults? Evidence from levels-of-processing and divided attention paradigms

In two experiments, we investigated the robustness and automaticity of adults’ and children’s generation of false memories by using a levels-of-processing paradigm (Experiment 1) and a divided attention paradigm (Experiment 2). The first experiment revealed that when information was encoded at a shallow level, true recognition rates decreased for all ages. For false recognition, when information was encoded on a shallow level, we found a different pattern for young children compared with that for older children and adults. False recognition rates were related to the overall amount of correctly remembered information for 7-year-olds, whereas no such association was found for the other age groups. In the second experiment, divided attention decreased true recognition for all ages. In contrast, children’s (7- and 11-year-olds) false recognition rates were again dependent on the overall amount of correctly remembered information, whereas adults’ false recognition was left unaffected. Overall, children’s false recognition rates changed when levels of processing or divided attention was manipulated in comparison with adults. Together, these results suggest that there may be both quantitative and qualitative changes in false memory rates with age.     

Retrieval of Episodic Information From Memory: Comparisons Among 3- and 4-Year-Olds, 7- and 8-Year-Olds,and Adults

Young children's and adults' recall of episodic information was explored in 4 experiments. The task required participants to recall a target noun presented as the last item of a 4-noun string of related (either categorically or thematically) or unrelated words. Providing all 3 preceding nouns or a subset of them cued recall. Experiment 1 found that 7- and 8-year-old children's recall was better with pictures as opposed to text, and children showed performance equal to adults with thematically related pictorial stimuli. Using pictorial stimuli, Experiment 2 showed that the number of cues present at retrieval affected 7- and 8-year-olds' recall. Experiments 3 and 4 tested recall of episodic information in 3- and 4-year-olds using pictorial stimuli. The results suggested that young children also have access to episodic information in memory and the number of cues present at retrieval influenced recall. The findings are discussed in the context of children's memory for events.     

The role of episodic memories in current and future well-being

The purpose of the present research was to examine the automatic role of psychological need satisfaction in episodic memories and in their associated networked memories on people's sense of well-being. In each of four studies, participants were asked to describe a main episodic memory and networked memories, that is, other memories related to their main episodic memory. Results of Studies 1 and 2 revealed that levels of need satisfaction in a main episodic memory and in its networked memories both uniquely contributed to the prediction of well-being (based on either participants' or peers' ratings). Study 3 examined the automatic effect of priming an episodic memory network on people's well-being in the here and now. Study 4 revealed that need satisfaction in episodic memory networks predicted changes in well-being over time. In addition, this relationship held after controlling for broad dispositional traits, mental health, and general need satisfaction ratings.     

Enhanced recognition and recall of new words in 7- and 12-year-olds following a period of offline consolidation

Recent studies of adults have found evidence for consolidation effects in the acquisition of novel words, but little is known about whether such effects are found developmentally. In two experiments, we familiarized children with novel nonwords (e.g., biscal) and tested their recognition and recall of these items. In Experiment 1, 7-year-olds were then retested on either the same day or the following day to examine changes in performance after a short delay compared with a longer delay that included sleep. Experiment 2 used two age groups (7- and 12-year-olds), with all participants being retested 24h later. The 12-year-olds accurately recognized the novel nonwords immediately after exposure, as did the 7-year-olds in Experiment 2 (but not in Experiment 1), suggesting generally good initial rates of learning. Experiment 1 revealed improved recognition of the novel nonwords after both short (3- to 4-h) and longer (24-h) delays. In contrast, recall was initially poor but showed improvements only when children were retested 24h later, not after a 3- to 4-h delay. Similar improvements were observed in both age groups despite better overall performance in 12-year-olds. We argue that children, like adults, exhibit offline consolidation effects on the formation of novel phonological representations.     

Changing scenes: memory for naturalistic events following change blindness

Research on scene perception indicates that viewers often fail to detect large changes to scene regions when these changes occur during a visual disruption such as a saccade or a movie cut. In two experiments, we examined whether this relative inability to detect changes would produce systematic biases in event memory. In Experiment 1, participants decided whether two successively presented images were the same or different, followed by a memory task, in which they recalled the content of the viewed scene. In Experiment 2, participants viewed a short video, in which an actor carried out a series of daily activities, and central scenes' attributes were changed during a movie cut. A high degree of change blindness was observed in both experiments, and these effects were related to scene complexity (Experiment 1) and level of retrieval support (Experiment 2). Most important, participants reported the changed, rather than the initial, event attributes following a failure in change detection. These findings suggest that attentional limitations during encoding contribute to biases in episodic memory.     

Remember judgments and the constraint of direct experience

The most direct assessment of episodic memory is provided by Remember versus Know judgments of recalled or recognised items. We investigate whether Remember judgments reflect episodic memories as a re-experience of formerly experienced events (mental time travel). If they do, they must obey the direct experience constraint: only directly experienced events can be re-experienced but not when the event is known through indirectly conveyed information. In two Experiments participants saw simple events in Power Point, e.g. a car exploding. In the direct experience condition these events were directly perceived. In three further conditions information about the object (particular car), the kind of event (explosion), or both were verbally conveyed. After controlling for a potential encoding specificity effect in Experiment 1, the frequency of Remember judgments was twice as high in the direct experience condition than in the other three conditions. This suggests that Remember judgments are—at least to some degree—subject to the direct experience constraint.