When Even Arbitrary Order Becomes Important: Developments in Reliable Temporal Sequencing of Arbitrarily Ordered Events

By late in the first year of life, children show temporally ordered recall of event sequences, the orders of which are constrained by enabling relations; they do not reliably recall arbitrarily ordered events. Using elicited imitation, in two experiments, we examined age-and experience-related changes in young children's recall of events, the orders of which are arbitrary. The changes were found to have implications for the efficacy of verbal reminding and to be related to developments in language. Specifically, on the basis of a single experience, 16-month-olds did not accurately recall arbitrarily ordered event sequences either immediately or after a two-week delay (Experiment 1); 22-month-olds recalled the events immediately, but not after the delay; by 28 months, children recalled the events even after the delay (Experiment 2A). This development was accompanied by changes in the ability to benefit from verbal reminders: 28-month-olds' recall was facilitated by provision of verbal reminders, whereas that of the younger children was not. Moreover, age-related changes in accurate reproduction of lengthy arbitrarily ordered event sequences were found to be related to developments in language (Experiment 2B). Critically, the limitations on 1-year-olds' performance that are overcome with age are not absolute: After three experiences, 16-month-olds accurately recalled the events after a two-week delay; their recall was facilitated by verbal reminders (Experiment 1). The implications of these findings are discussed.     

Video reminders in a representational change task: memory for cues but not beliefs or statements

Two experiments investigated the effect of video reminders on 3-year-olds' performance in a representational change task. In Experiment 1, children in a video support condition viewed videotapes of their initial incorrect statements about a misleading container prior to being asked to report their initial belief. Children in a control condition viewed an irrelevant videotape. Despite reporting what they had said on the videotape, children in the video support condition typically failed the representational change task. Experiment 2 replicated the main findings from Experiment 1 and also revealed that a video reminder failed to increase the likelihood that children would correctly report what they had said about the object. Results are discussed in terms of the processes whereby mnemonic cues might affect performance on tasks assessing theory of mind.     

Returning to the scene: reminders and context reinstatement enhance children's recall.

Two studies examined the efficacy of context reinstatement as a reminder in enhancing 5- to 7-year-old children's recall. In Experiment 1, children who had been interviewed shortly after an event were reinterviewed 6 months later. Children exposed to a context reminder 24 hr before the 6-month interview and children interviewed in the event context did not differ but reported significantly more information in a verbal interview than children receiving a standard interview. A control group experienced the reminder but not the event and established that the effects of the reminder were not due to new learning. There was no effect of the reminder on accuracy and no effect in reenactment. In Experiment 2, children were interviewed for the first time after 6 months, and effects of the reminder were found for both verbal recall and reenactment. Nonverbal reminders may effectively enhance the amount of information children report without decreasing accuracy.     

Draw It again Sam: the effect of drawing on children's suggestibility and source monitoring ability

Preschool children (aged 3 to 6 years) participated in a magic show. Later, the children were given repeated true and false reminders about the show. Half the children were asked to draw these true and false reminders (drawing condition) and half the children were asked questions about the reminders but not to draw them (question condition). Later, children in the drawing condition had better recall of true reminders than children in the question group; however, children in the drawing group also recalled more false reminders than children in the question group. Finally, although children in the drawing group had better memory of the source of the reminders than children in the question group, both groups equally reported that the false reminders actually happened.     

Developmental differences in schema dependency for temporally ordered story events

This research project was undertaken to investigate whether temporally ordered story events would be recalled in logical sequence as opposed to presentation order by various ages and under various task conditions. A 24-hour delayed condition was used as well as immediate recall. Six-year-olds, 8-year-olds, and adults were asked to recall four narratives. Instructions given were either vague or specifically required subjects to recall events exactly as they had been presented. Following the delayed recall, a picture-sequencing task was adminstered to assess whether picture cues would enable subjects to demonstrate awareness of input order even though they had reordered events in recall. All subjects reordered more during the delayed recall than during the immediate recall. Age differences (p<0003) occurred in the ability of subjects to demonstrate verbatim memory on the picture-sequencing task. Findings suggest that in contrast to adults, once children have reordered narrative events in memory, they no longer have an alternative verbatim version available. Results also suggest a greater schema dependency in children than in adults in recall tasks.     

"Don't try this at home": toddlers' imitation of new skills from people on video

Imitation of people on educational television is a potential way for very young children to learn new skills. Although toddlers in previous studies exhibited a “video deficit” in learning, 24-month-olds in Study 1 successfully reproduced behaviors modeled by a person who was on video as well as they did those modeled by a person who was present in the room (even after a 24-h delay). Neither displaced filming context nor cuts between actions affected toddlers’ imitation from video. Shortening the demonstration in Study 2 affected imitation in the video condition but not in the live condition. In Study 3, 24-month-olds who viewed the original longer videos on their family TV screens (with which they had a viewing history) imitated significantly less than those who viewed the videos on the laboratory monitor. Imitation of a live modeler was the same across settings (home or lab). Implications for toddlers’ judgments of reliable information sources and for the design of educational television programs are discussed.     

Time and again: effects of repetition and retention interval on 2 year olds' event recall

How and what very young children remember is a central question for understanding the course of memory development. In this research, we examined the effects of two factors on 2-year-old children's ability to recall novel events: repetition of the experience and time since experience. Twenty 24-month-old and twenty 28-month-old children participated in unusual laboratory play events. Half of the children returned after a 2-week delay and again after a 3-month delay (repeated experience condition); the remaining children returned only after 3 months (single experience condition). Memory was assessed by asking children to reenact the events. Recall was generally accurate, and there were no significant effects of age. All children recalled more information about the activities associated with the event than about the objects. Surprisingly, children in the repeated experience condition recalled as much about the events at the 3-month retention interval as at the 2-week retention interval. Further, children in this condition recalled more information at the 3-month retention interval than children in the single experience condition, suggesting that reexperiencing an event may guard against long-term forgetting.     

When the event is more than the sum of its parts: 9-month-olds' long-term ordered recall

Research suggests that 9-month-old infants are able to recall single object-specific actions over delays of 24 hours. In the present research we investigated whether 9-month-olds are able to recall over more extended delays, and to recall the temporal order of events, as well as the individual actions in them. In addition, we investigated whether recall can be enhanced by pre- and/or re-exposure to target events. Using elicited imitation of novel, multi-step event sequences, we demonstrated that, as a group, 9-month-olds are able to recall target actions after delays of five weeks. However, after this long delay, only 45% of the infants recalled the temporal order of the events. Re-exposure to events during the delay interval proved necessary for boys, but not for girls; pre-exposure to events did not affect later recall. The implications of individual differences in infants' recall ability for the understanding of the development of the neural correlates of declarative memory are discussed.     

18- and 24-month-olds' discrimination of gender-consistent and inconsistent activities

18- and 24-month-olds' ability to discriminate gender-stereotyped activities was assessed. Using a preferential looking paradigm, toddlers viewed male and female actors performing masculine and feminine-stereotyped activities. Consistent with our predictions, and previous research, 24-month-olds, but not 18-month-olds, looked longer at the gender-inconsistent activities than the gender-consistent activities. Results are discussed in terms of toddlers emerging gender stereotypes and perception of everyday events.     

Props,not pictures,are worth a thousand words: verbal accessibility of early memories under different conditions of contextual support

When they are tested nonverbally, even young children demonstrate long-term recall. There have been few studies of whether early memories later are verbally accessible; the results of those that exist are mixed. Inconsistencies may be due to differences in the contextual cues provided at the time of recall. In two experiments, children 13–20 months were exposed to multi-step sequences and tested for nonverbal recall after 3–6 months. At age 3 years, they were tested verbally, under varying conditions of contextual support: in the original laboratory with event-related props versus at home with photographs of the props (Experiment 1), and at home with props (Experiment 2). Children younger than 20 months at initial experience of the events did not demonstrate verbal recall. Children who were 20 months at the initial exposure recalled verbally, as long as they had physical props as cues, regardless of whether testing took place at home or in the laboratory. This research informs the conditions under which memories from very early childhood later can be recalled verbally. Copyright © 2004 John Wiley & Sons, Ltd.     

Effect of verbal messages with reminders to communicate driving situations to alter driver behavior in conditional driving automation

In conditionally automated driving, drivers are relieved of steering (hands-off), accelerating, and braking actions as well as of continuous monitoring of driving situations and the system operation status (eyes off). This enables continuously engagement in non-driving-related activities. Managing the allocation of a driver’s attention to the surrounding environment and automation status presents a major challenge in human–machine system design. In this study, we propose a verbal message with a reminder (monitoring request) to divert the driver’s attention from non-driving-related activities to peripheral monitoring under conditionally automated driving. When the system encounters events related to weather, traffic, and road geometry, it provides a verbal message pertaining to the road surroundings (e.g., “It is foggy outside”) to the driver. After three seconds, the system provides a reminder message (i.e., “Did you confirm it?”) to the driver. We explore two questions: (1) how does the message with the reminder affect the driver’s attention allocation, and (2) how does the message with the reminder affect the driver behavior in response to a request to intervene (RTI). With a driving simulator, we designed a repeated measures mixed design with a between-participant factor of “Driving condition” and within-participant factors of “Event type” and “Measurement time”. Three driving conditions were established as follows: no messages, messages without reminders, and messages with reminders. Twenty-seven drivers participated as participants in the driving simulator experiment. Results showed that the reminder message was effective in allocating the participants’ attention to the surrounding environment, and the participants took over the driving task after spending more time understanding the take-over situation in the condition of messages with reminders compared to those in the condition of no messages. We conclude that the proposed reminder message can direct drivers’ attention to the road surroundings during conditionally automated driving. In the future, we plan to design adaptive verbal monitoring requests to adjust the reminder message according to the situation.     

Prospective memory: When reminders fail

A frequent assumption in the area of prospective memory is that a reminder to do an activity in the future improves the likelihood of doing the activity. The results of four experiments indicated, however, that the most general version of this assumption is incorrect. Subjects were either reminded of a prospective memory task several times during a retention interval or not reminded of the prospective memory task. The most effective reminders referred both to the prospective memory target events and to the intended activity. Reminders that referred only to the target events did not improve prospective memory (relative to a no-reminder control). Reminders that referred only to the intended activity did improve prospective memory, but not to the level of reminders that referred both to the target events and to the intended activity. Instructions to imagine oneself performing the prospective memory task did not further improve prospective memory. Neither the delay between the prospective memory instructions and the prospective memory cover task nor the delay between a reminder and a prospective memory target event significantly influenced performance. The results, which are discussed in terms of theoretical and practical implications, support a new theory of prospective memory and suggest surprising conditions under which reminders fail to benefit prospective memory.     

Differential memory-preserving effects of reminders at 6 months

Although reactivation and reinstatement reminders differ procedurally, differences in their memory-preserving effects have been described as artifactual. In three experiments, we examined this conclusion. One hundred and twelve 6-month-olds learned an operant task, forgot it, received a reactivation or reinstatement reminder to recover the inactive memory, and were tested after increasing delays until they forgot it again. In Experiments 1a and 1b, a single reactivation reminder extended infants' memory of an operant mobile task for 2 weeks after reminding, but a single reinstatement extended it for 4 weeks, when testing was discontinued. In Experiment 2, a single reinstatement extended 6-month-olds' memory of an operant train task for 19 weeks after reminding, when infants were almost 1 year old. After reactivation, infants remember this task for only 2 weeks. The finding that the memory-preserving effect of reinstatement is greater by an order of magnitude suggests that procedural differences between the two reminders have functional significance.     

The child in time: the influence of parent-child discussion about a future experience on how it is remembered

We investigated the influence of preparation provided by parents on preschoolers' recall. One day before children participated in a staged novel event, parents discussed the event with their child either with (verbal+photos) or without (verbal) photographs. Parents and children in a control condition read an unrelated story. Then 8-10 days later the children were interviewed about the event. Children in the verbal+photos condition recalled significantly more than those in the control condition. Parental preparation style (e.g., evaluations, hypothetical language) was associated with the child's contributions to the preparatory discussion, but no aspect of parent or child style or content was associated with children's verbal recall. Similarly, there were no significant associations between children's performance on a task of episodic future thinking, and their preparatory discussion or recall, although episodic future thinking was strongly associated with language ability. The potential underlying mechanisms and theoretical implications are discussed.     

Toddlers’ referential understanding of pictures

Pictures are referential in that they can represent objects in the real world. Here we explore the emergence of understanding of the referential potential of pictures during the second year of life. In Study 1, 15-, 18-, and 24-month-olds learned a word for a picture of a novel object (e.g., “blicket”) in the context of a picture book interaction. Later they were presented with the picture of a blicket along with the real object it depicted and asked to indicate the blicket. Many of the 24-, 18-, and even 15-month-olds indicated the real object as an instance of a blicket, consistent with an understanding of the referential relation between pictures and objects. In Study 2, children were tested with an exemplar object that differed in color from the depicted object to determine whether they would extend the label they had learned for the depicted object to a slightly different category member. The 15-, 18-, and 24-month-old participants failed to make a consistent referential response. The results are discussed in terms of whether pictorial understanding at this age is associative or symbolic.     

Retrieval-based learning: The need for guided retrieval in elementary school children

Three experiments were aimed at adapting retrieval practice techniques that are effective with college students to work with elementary school children. Children participated in their classrooms and completed activities with educational texts selected from the school curriculum. In Experiment 1, when children were asked to freely recall the texts, they recalled very little of the material (about 10%) and showed almost no improvement after rereading. In another condition that involved creating concept maps, the children produced only about 20% of the ideas on their maps, even though they viewed the texts during the entire activity. Experiments 2 and 3 explored ways to provide support during retrieval activities. In Experiment 2, children were very successful at retrieving knowledge on concept maps that were partially completed. In Experiment 3, a question map activity, where questions were displayed in a relational map format, was effective for guiding retrieval practice and improving learning relative to repeated studying. The results demonstrate the importance of examining strategies that work with college students with young children in educational settings using authentic materials. The results also highlight the need for guided retrieval practice in young children.     

Children's Use of Mnemonic Strategies: Variability in Response to Metamemory Training

In this study, 8- to 12-year-old children were tested to determine their level of use of a strategy for organizing lists of low-associated words into semantic groups. Then, on the basis of their scores in the strategy tests, the children were placed in either a strategic or nonstrategic group. The groups were divided into a sort-instruction training condition, in which they were told to group words so that they “go together” in some way, and a metamemory training condition, in which these instructions were supplemented by feedback, strategy reminders, and opportunities to self-test. One week later, each child's strategy use was reassessed. Children in the strategic group sorted semantically throughout training and transfer, and they showed high recall, regardless of condition. Children in the nonstrategic group showed high strategy use and recall during training, but they showed significantly more variability in recall than did the children in the strategic group. Children in the nonstrategicmetamemory condition who benefited from training were also more likely to transfer the use of the strategy than were children trained in the sort-instruction condition.     

On the relation between the acquisition of singular-plural morpho-syntax and the conceptual distinction between one and more than one

We investigated the relationship between the acquisition of singular-plural morpho-syntax and children's representation of the distinction between singular and plural sets. Experiment 1 tested 18-month-olds using the manual-search paradigm and found that, like 14-month-olds (Feigenson & Carey, 2005), they distinguished three objects from one but not four objects from one. Thus, they failed to represent four objects as 'plural' or 'more than one'. Experiment 2 found that children continued to fail at the 1 vs. 4 manual-search task at 20 months of age, even when told, via explicit morpho-syntactic singular-plural cues, that one or many balls are being hidden. However, 22- and 24-month-olds succeeded both with and without verbal cues. Parental report data indicated that most 22- and 24-month-olds, but few 20-month-olds, had begun producing plural nouns in their speech. Also, the success among the older children was due to those children who had reportedly begun producing plural nouns. We discuss a possible role for language acquisition in children's deployment of set-based quantification and the distinction between singular and plural sets.     

How accurate are time-use reports? Effects of cognitive enhancement and cultural differences on recall accuracy

In order to assess the accuracy of time-use reports, 80 young adults were observed for 2-hour periods, and were interviewed about their activities by a different person the following day. Two experiments were performed. In the first, three different levels of cognitive enhancement were used to improve recall accuracy. Subjects were 60 California college students, 20 per group. In the second study the maximum enhancement condition was replicated with 20 Guatemalan subjects, similar in age, sex and level of education to the California subjects. Both the accuracy of their recall of specific activities, and the accuracy of their time-duration estimates were calculated. Results indicated that the enhancement conditions in Study 1 significantly increased both the number of activities recalled accurately (from 40 to 63 per cent) and the amount of time accurately recalled (from 58 to 70 per cent). In Study 2 the Guatemalans recalled 60 per cent of their activities accurately, and recalled as much time accurately as the Californians. The Guatemalans were significantly more likely to underestimate their time. In other words, when they made errors, these were almost always underestimations. Most of the recall error could be accounted for by forgetting an activity altogether, rather than by estimating its time inaccurately.     

Toddlers’ Understanding of Peers’ Emotions

The second year of life sees dramatic developments in infants’ ability to understand emotions in adults alongside their growing interest in peers. In this study, the authors used a social-referencing paradigm to examine whether 12-, 18-, and 24-month-old children could use a peer's positive or negative emotion messages about toys to regulate their own behavior with the toys. They found that 12-month-olds decreased their play with toys toward which a peer had expressed either positive or negative emotion compared with play following a peer's neutral attention toward a toy. Also, 18-month-olds did not respond systematically, but 24-month-old children increased their toy play after watching a peer display negative affect toward the toy. Regardless of their age, children with siblings decreased their play with toys toward which they had seen a peer display fear, the typical social-referencing response. The authors discuss results in the context of developmental changes in social understanding and peer interaction over the second year of life.