The effects of prior knowledge on children's memory and suggestibility

In this study, 5- and 6-year-olds were read a story and asked to recall its details. Two independent factors-prestory knowledge and poststory suggestions-were crossed to examine the effects on children's story recall. The results indicated that prestory social knowledge about the story protagonist as well as academic knowledge relating to the content of the story influenced the accuracy of children's recall immediately after the story presentation. Following the suggestive interview, children reported interviewer-provided social and academic misinformation to a greater extent when the misinformation was consistent with their prior knowledge. In contrast, children were more likely to refute misinformation that contradicted their academic knowledge. These findings are discussed in terms of the mechanisms underlying the knowledge-memory and knowledge-suggestibility linkages.     

Recency effects in memory,as a function of modality of intervening events

Summary Word lists of fifteen items were presented to eye or to ear, with recall either immediately, or after a visual task, or after an auditory one. Instructions were to recall the last items first. An intervening task using the same modality greatly reduced recall of the last items presented; whereas a visual task did not do so for acoustically presented items. An auditory task reduced visual memory. These results suggest a specific auditory memory for recent events, over-written by subsequent auditory events.This research was supported by the Medical Research Council. The experimental work was performed at the Applied Psychology Unit, Cambridge.     

The effects of noise and gender on children's episodic and semantic memory

The main objectives in the present study were to examine meaningful irrelevant speech and road traffic noise effects on episodic and semantic memory, and to evaluate whether gender differences in memory performance interact with noise. A total of 96 subjects, aged 13-14 years (n = 16 boys and 16 girls in each of three groups), were randomly assigned to a silent or two noise conditions. Noise effects found were restricted to impairments from meaningful irrelevant speech on recognition and cued recall of a text in episodic memory and of word comprehension in semantic memory. The obtained noise effect suggests that the meaning of the speech were processed semantically by the pupils, which reduced their ability to comprehend a text that also involved processing of meaning. Meaningful irrelevant speech was also assumed to cause a poorer access to the knowledge base in semantic memory. Girls outperformed boys in episodic and semantic memory materials, but these differences did not interact with noise.     

Partial picture effects on children's memory for sentences containing implicit information

Two experiments were conducted examining the effects of partial picture adjuncts on young children's coding of information that was implied in sentences. In the two most critical conditions of these studies, subjects were presented sentences specifying a subject, an action, and a direct object with the instrument used to carry out the action not specified in the sentence (e.g., The workman dug a hole in the ground). Implicit-sentence-only subjects received only the sentences, whereas the implicit sentence + partial picture subjects also viewed a partial picture depicting the action in the sentence minus the implied instrument. The main hypothesis was that subsequent recall of the sentences given the implied instrument as a cue would be facilitated by the partial pictures provided at study, since they would lead the children to infer the instrument. That occurred with 6- to 7-year-old children, but not with preschool children. Consistent with the conclusion that the partial pictures prompted 6- to 7-year-olds to infer the instruments, implicit sentence + partial picture subjects recalled as much as subjects in two other conditions, one in which subjects were explicitly told the instruments at study and one in which subjects saw the instruments depicted in pictures at study. In contrast, preschool subjects who heard explicit sentences containing the instruments outperformed subjects who heard implicit sentences even when the implicit sentences were accompanied by pictures depicting the instruments. This failure of complete pictures to facilitate preschoolers' recall of information implied in sentences contrasts with the many demonstrations of prose learning facilitation when picture and sentence contents explicitly and completely overlap. In summary, there were developmental differences in whether (a) partial pictures significantly facilitated inferencing (and subsequent cued recall) and (b) complete pictures containing information not explicitly stated in sentences promoted cued recall of the sentences.     

The effects of interacting in repeated events on children's eyewitness memory and source monitoring

Accurate eyewitness memory of an event may be affected by exposure to and degree of involvement with other related events. In this study, we investigated whether interacting in a related video event affected children's accounts of a real-life target event, and whether interacting in the target event affected memory for different details within the target event. Four-, 6-, and 9-year-old children interacted with an adult who made a puppet. Half of the children in each age group also interacted with a video of a similar event (interactive condition) and half sat and watched the video without interacting (watch condition). When asked non-misleading questions a week later, children in the interactive condition confused the two events more than those in the watch condition. The 4-year-olds in the interactive condition reported a higher rate of confusions in free recall than the 4-year-olds in the watch condition. There were no effects of interaction on responses to misleading questions. The 6- and 9-year-olds were more accurate at answering questions related to actions they themselves had performed than actions performed by the experimenter, although this pattern was reversed for the 4-year-olds. The results are discussed in terms of children's eyewitness memory. © 1998 John Wiley & Sons, Ltd.     

The impact of perceived self-efficacy on memory for aversive experiences

Self-efficacy is a key construct underlying healthy functioning and emotional well-being. Perceptions of uncontrollability, unpredictability, and low self-efficacy are consistently associated with negative mental health outcomes, such as post-traumatic stress disorder (PTSD). To test the causal relation between perceived coping self-efficacy and stress responses we employed a trauma film paradigm in which college students (N=33) viewed a graphic film of the aftermath of a motor vehicle accident following a high (HSE) or low self-efficacy (LSE) induction. Participants were tested for intrusions, distress, and memory recall for the film over the following 24 hours. LSE participants recalled more central details than HSE participants. Further, HSE participants reported fewer negative intrusions immediately following the film and at 24 hours. These findings suggest that strategies that increase perceived coping self-efficacy may reduce intrusive recollections of an aversive event, and also reduce the attentional bias associated with remembering aversive stimuli.     

The effect of questioning on young children's memory for an event

The effect of adult questioning on young children's memory for an event was examined. Three groups of 4- and 5-year-old children experienced two special events. The questioning group was then asked a set of questions about one of the events on four different occasions over a 7-week period. At the end of the 7 weeks, all children were tested for recall of the two events. The experience of answering questions enhanced the memory performance of the children in the questioning group. However, comparison of the performance of the questioning group with that of two control groups showed that their memory improvement was extremely specific: (a) The questioning group did better only on the specific questions they had been repeatedly asked, (b) There was no general enhancement of recall; they were no better on new questions about the same event, (c) The enhancement was not specific to the experience of retrieving information from long-term memory; the performance of a control group with no long-term memory demands was almost identical to that of the questioning group. The results of this study support the view that adult questioning of young children enhances memory for the specific information about which questions have been asked, but it does not have generalized effects on memory performance or development.     

The effects of word length and phonemic similarity in young children's short-term memory

Two experiments tested the hypothesis that word length and phonemic similarity effects in young children's recall with auditory presentation result from verbal output, and not: (1) rehearsal in the case of word length effects; (2) confusion at input in the case of phonemic similarity effects. In an auditorily presented probed recall task, where there were no full verbal output requirements, children aged five years did not show either effect. Children aged seven years showed both word length and phonemic similarity effects. It was concluded that, in children of age five, word length effects can not necessarily be taken as evidence for rehearsal, nor can the phonemic similarity effect be assumed to result from confusion at input. It is suggested that the process of saying a list verbally may cause both of these effects, and that care must be taken to distinguish input and output processes in the development of children's short-term memory.     

The effects of physical work, mental work, and quantity on children's time perception

An experiment was conducted to examine the effects of work and quantity cues on children's time perception. Ninety-seven children in kindergarten and Grades 2, 4, and 6 lifted and transferred pipes under eight different conditions, after which they reproduced the perceived time taken to move the pipes. The conditions varied by quantity (two/four pipes), by mental work (no-matching/matching), and by physical work (light/heavy pipes). Significant main effects were found for quantity, physical work, and mental work, and for the quantity x age and mental work x physical work interactions. These results can help to disentangle possible confounds among these variables in the classic Piagetian experiments about their effects on time judgment and perception.     

Timing moderates the effects of repeated suggestive interviewing on children's eyewitness memory

The relative role of the timing and repetition of misinformation on the accuracy of children's recall was examined in two experiments. Kindergarten children participated in a magic show and about 40 days later had a memory test. Between the magic show and the memory test, the children were suggestively interviewed either one time in a relatively ‘early’ interview (temporally closer to the magic show than the memory test) or a relatively ‘late’ interview (closer to the memory test than the magic show), or in both suggestive interviews. The timing of the suggestive interviewing was manipulated so that the interview was temporally distant from the event or memory test or temporally close to the event or memory test. Repeated interviewing heightened misinformation effects only when the children received the two interview sessions temporally close to the event and memory test. Copyright © 2004 John Wiley & Sons, Ltd.     

Infant memory for musical experiences

Recent findings suggest that infants can remember words from stories over 2 week delays (Jusczyk, P. W., & Hohne, E. A. (1997). Infants' memory for spoken words. Science, 277, 1984-1986). Because music, like language, presents infants with a massively complex auditory learning task, it is possible that infant memory for musical stimuli is equally powerful. Seven-month-old infants heard two Mozart sonata movements daily for 2 weeks. Following a 2 week retention interval, the infants were tested on passages of the familiarized music, and passages taken from similar but novel music. Results from two experiments suggest that the infants retained the familiarized music in long-term memory, and that their listening preferences were affected by the extent to which familiar passages were removed from the musical contexts within which they were originally learned.     

The effects of social influence on children's memory reports: the omission and commission error asymmetry

Children in two age groups (7 vs. 12 yrs, N= 174) individually interacted with a stranger and were later interviewed about this event. Right before the interview, each child encountered the stranger once again and he engaged in a conversation where he either suggested that a (central or peripheral) detail originally present in the event had actually not been there or that an originally non-present (central or peripheral) detail had in fact been there. It was hypothesized that the two types of misinformation would result in omission and commission errors respectively. The results showed that the social influence resulted in an asymmetric effect (i.e., more commission than omission errors). Importantly, we also found that the children made more errors with respect to the peripheral detail (a suitcase), compared to the central detail (a passenger). Younger children did not make more errors (neither omission nor commission errors) than older children.     

The effects of errors on children's performance on a circle-ellipse discrimination

Children first learned by means of a teaching program to discriminate a circle from relatively flat ellipses. Children in the control group then proceeded into a program which gradually reduced the difference between the circle and the ellipses. They advanced to a finer discrimination when they made a correct choice, and reversed to an easier discrimination after making errors ("backup" procedure). The children made relatively few errors until they approached the region of their difference threshold (empirically determined under the conditions described). When they could no longer discriminate the forms, they learned other bases for responding that could be classified as specifiable error patterns. Children in the experimental group, having learned the preliminary circle-ellipse discrimination, were started at the upper end of the ellipse series, where it was impossible for them to discriminate the forms. The backup procedure returned them to an easier discrimination after they made errors. They made many errors and reversed down through the ellipse series. Eventually, most of the children reached a point in the ellipse series where they abandoned their systematic errors and began to make correct first choices; then they advanced upward through the program. All of the children advanced to ellipse sizes that were much larger than the ellipse size at the point of their furthest descent.     

The endurance of children's working memory: a recall time analysis

We analyze the timing of recall as a source of information about children’s performance in complex working memory tasks. A group of 8-year-olds performed a traditional operation span task in which sequence length increased across trials and an operation period task in which processing requirements were extended across trials of constant sequence length. Interword pauses were longer than are commonly found in immediate serial recall tasks yet shorter than for reading span. These pauses increased with the demands of recall, decreased across the output sequence, and were to some extent predictive of scholastic ability. Overall, timing data illustrate that recall in working memory tasks involves subtle processes of item access rather than simple readout of information from an immediate store.     

The adaptive nature of children's overestimation in a strategic memory task

Kindergarten, first-, and third-grade children were given a multitrial sort-recall task with different items on each trial. Children were asked to predict how many items they would recall prior to each trial. We classified children into high- and low-overestimation groups based on their prediction accuracy on the first two trials and assessed changes in recall and strategy use over trials (trials 4/5 minus trials 1/2). Following predictions, at all grades, children in the high-overestimation group showed greater gains (or fewer losses) in recall than children in the low-overestimation group. Differences in strategy use over trials were generally nonsignificant. The results were interpreted as reflecting the adaptive nature of children's overestimation of their cognitive abilities.     

The effects of an afterschool physical activity program on working memory in preadolescent children

The present study examined the effects of a 9-month randomized control physical activity intervention aimed at improving cardiorespiratory fitness on changes in working memory performance in preadolescent children relative to a waitlist control group. Participants performed a modified Sternberg task, which manipulated working memory demands based on encoding set sizes, while task performance and the contingent negative variation (CNV) event-related brain potential were measured. Analyses revealed that the physical activity intervention led to increases in cardiorespiratory fitness and improved Sternberg task performance. Further, the beneficial effects of the physical activity intervention were greater for a task condition requiring greater working memory demands. In addition, the intervention group exhibited larger initial CNV at the frontal electrode site, relative to the waitlist group at post-test; an effect not observed during the pre-test. These results indicate that increases in cardiorespiratory fitness are associated with improvements in the cognitive control of working memory in preadolescent children.     

Priming effects that span an intervening unrelated word: implications for models of memory representation and retrieval.

Several studies have reported priming effects that span an intervening unrelated word (Davelaar & Coltheart, 1975; Meyer, Schvaneveldt, & Ruddy, 1972). More recently, other investigators have suggested that such relatedness effects are the result of postaccess processes (Gough, Alford, & Holley-Wilcox, 1981; Masson, 1991; Ratcliff & McKoon, 1988). In fact, these investigators claim that when procedures are used that discourage the use of postaccess processes, relatedness effects do not span intervening unrelated words. The present experiments demonstrate reliable relatedness effects with procedures that eliminate postaccess processes. These results are consistent with the notion of spreading activation among local representations in memory. Implications for the issue of local versus distributed representations are discussed.     

The role of cuing and organization in children's memory for events

Children's memory for a standardized, hierarchically organized event, making clay, was tested in two experiments. Immediately after participating in this event and again 2 weeks later, children described how they had made the clay. In Experiment 1, action and object cues were presented but only action cues greatly facilitated recall. Children who remade the clay reported more information and also reported more of the actions most central to the goal of the event during delayed recall. In Experiment 2, verbal cues representing two levels in the event hierarchy were presented, but neither aided recall. These and other patterns in the data indicated that, at most, the rudiments of a hierarchical structure had emerged after a single experience. These results were discussed in terms of their implications for the development and organization of event memories.     

The effects of repeated experience on children's suggestibility

The effect of suggestive questions on 3- to 5-year-old and 6- to 8-year-old children's recall of the final occurrence of a repeated event was examined. The event included fixed (identical) items as well as variable items where a new instantiation represented the item in each occurrence of the series. Relative to reports of children who participated in a single occurrence, children's reports about fixed items of the repeated event were more accurate and less contaminated by false suggestions. For variable items, repeated experience led to a decline in memory of the specific occurrence; however, there was no increase in susceptibility to suggestions about details that had not occurred. Most errors after repeated experience were intrusions of details from nontarget occurrences. Although younger children and children who were interviewed a while after the event were more suggestible, respectively, than older children and those interviewed soon after the event, repeated experience attenuated these effects.