characters and clues: factors affecting children's extension of knowledge through integration of separate episodes

Children build up knowledge about the world and also remember individual episodes. How individual episodes during which children learn new things become integrated with one another to form general knowledge is only beginning to be explored. Integration between separate episodes is called on in educational contexts and in everyday life as a major means of extending knowledge and organizing information. Bauer and San Souci (2010) provided an initial demonstration that 6-year-olds extend their knowledge by integrating between separate but related episodes; the episodes shared a high level of surface similarity. Experiments 1A and 1B of the current research were tests of integration under low and high levels of surface similarity, respectively. In Experiment 1A, when surface similarity of the episodes was low, 6-year-olds integrated between passages of text, yet their performance was not as robust as observed previously. In Experiment 1B, when surface similarity of the episodes was high, a replication of Bauer and San Souci's results was observed. In Experiment 2, we tested whether a "hint" to consult the information learned in the passages improved performance even when surface level similarity was low. The hint had a strong facilitating effect. Possible mechanisms of integration between separate yet related episodes are discussed.     

知识整合的时间进程：ERP研究

本研究借助ERP技术,采用分离句子范式,考察了被试通过整合主干事实生成新知识的时间进程。结果发现：（1）知识整合事实相对于传递性推理事实和新颖事实诱发了更小的N400,与众所周知事实没有显著差异,表明通过整合生成的新信息已经快速纳入了语义知识库;（2）对比两次呈现,延迟性整合事实在第二次呈现的350ms之后波幅显著下降,与众所周知事实没有显著差异,表明知识经验影响了整合的时间进程,相较两个新信息之间的即时整合,新旧信息之间的延迟整合需要更多的时间。     

Going beyond the facts: Young children extend knowledge by integrating episodes

The major question posed in this research was whether 4- and 6-year-olds productively extend their knowledge by integrating information acquired in separate episodes. The vehicle was a read-aloud activity during which children were presented with a novel fact in each of two passages. In Experiment 1, both age groups showed evidence of integration between the passages. For the 6-year-olds, the evidence came in the form of responses to open-ended questions. The 4-year-olds recognized the correct answers but did not generate them in the open-ended question format. The 6-year-olds who generated the correct answers also were likely to recall both of the individual facts presented in the passages. In Experiment 2, we tested whether the 4-year-olds’ integration performance would improve if their memory for the individual facts improved. Extra exposure to the individual facts resulted in higher levels of integration performance in both recall and recognition testing. The roles of memory and other potential sources of age-related differences in integration performance are discussed.     

Young adults self-derive and retain new factual knowledge through memory integration

The present research investigated the retention of new factual knowledge derived through integration of information acquired across temporally distributed learning episodes. Young adults were exposed to novel facts as they read long lists of seemingly unrelated information, one sentence at a time. They then were presented open-ended questions, the answers to which could be self-derived through integration of pairs of facts from the list. Experiment 1 was the first test of self-derivation of new factual knowledge through integration in adults using open-ended testing (as opposed to forced-choice testing). Participants successfully self-derived integrated knowledge under these more challenging conditions. Experiment 2 was a test for long-term retention of newly self-derived information. Newly derived knowledge remained accessible after a 1-week delay. Striking individual differences were also observed, which were related to whether individuals spontaneously identified the relational structure of the learning task. Insight into the relation between explicit task knowledge and strategic processing was also revealed through examination of response speed at the time of test. Specifically, knowledge of the task structure was associated with response latencies on unsuccessful (but not successful) trials, such that participants who were aware of the opportunity to integrate spent longer when they were subsequently unsuccessful, presumably reflecting directed search strategies and heightened perseverance when those processes failed. Together, the present findings provide direct evidence for the role of memory integration in the long-term accumulation of a semantic knowledge base and have theoretical implications for our understanding of this fundamental form of learning.     

Integrating unseen events over time

Events often share elements that guide us to integrate knowledge from these events. Integration allows us to make inferences that affect reactions to new events. Integrating events and making inferences are thought to depend on consciousness. We show that even unconsciously experienced events, that share elements, are integrated and influence reactions to new events. An unconscious event consisted of the subliminal presentation of two unrelated words. Half of subliminal word pairs shared one word ('winter red', 'red computer'). Overlapping word pairs were presented between 6s and 78 s apart. The test for integration required participants to judge the semantic distance between suprathreshold words ('winter computer'). Evidence of integration was provided by faster reactions to suprathreshold words that were indirectly related versus unrelated. This effect was independent of the time interval between overlapping word pairs. We conclude that consciousness is no requirement for the integration of discontiguous events.     

Preschool children's use of cues to generic meaning

Sentences that refer to categories - generic sentences (e.g., "Dogs are friendly") - are frequent in speech addressed to young children and constitute an important means of knowledge transmission. However, detecting generic meaning may be challenging for young children, since it requires attention to a multitude of morphosyntactic, semantic, and pragmatic cues. The first three experiments tested whether 3- and 4-year-olds use (a) the immediate linguistic context, (b) their previous knowledge, and (c) the social context to determine whether an utterance with ambiguous scope (e.g., "They are afraid of mice", spoken while pointing to 2 birds) is generic. Four-year-olds were able to take advantage of all the cues provided, but 3-year-olds were sensitive only to the first two. In Experiment 4, we tested the relative strength of linguistic-context cues and previous-knowledge cues by putting them in conflict; in this task, 4-year-olds, but not 3-year-olds, preferred to base their interpretations on the explicit noun phrase cues from the linguistic context. These studies indicate that, from early on, children can use contextual and semantic information to construe sentences as generic, thus taking advantage of the category knowledge conveyed in these sentences.     

The role of inhibitory control in forgetting semantic knowledge

Previous research has shown that episodic retrieval recruits inhibitory processes that impair memory for related events. We report two experiments examining whether inhibitory processes may also be involved in causing semantic memory lapses. In a semantic retrieval-practice paradigm, subjects were given trials presenting a cue (a homograph in Experiment 1, a category in Experiment 2) linked to many different items in semantic memory. For each cue, subjects used general knowledge to generate no (baseline), one, four, or eight different items of semantic knowledge. Afterward, we determined through an apparently unrelated free-association test whether a critical nonpracticed concept associated to the cue had been inhibited. Both experiments found that generating items from semantic memory suppressed competing concepts, and that this impairment was cue independent. These findings show that inhibitory control processes overcome interference during semantic retrieval and that recruitment of these processes may contribute to semantic forgetting.     

Semantic self-knowledge and episodic self-knowledge: independent or interrelated representations?

In this study of the structure of self-knowledge, we examined priming effects for the recall of personal episodes in order to investigate whether abstract trait knowledge and personal episodes are independent mental representations. We found that accessing similar abstract representations of traits facilitated a faster recall of related personal episodes than did accessing irrelevant abstract representations of traits (Experiments 1 and 2), reading a nonword prime (Experiments 2 and 3), accessing knowledge of one's mother (Experiment 3), or accessing semantic knowledge (Experiment 3). Contrary to previous findings, which indicated that abstract trait knowledge is represented independently of related personal episodes (e.g., Klein & Loftus, 1993; Tulving, 1993), our results suggest that abstract trait knowledge is associated with personal episodes, and therefore that semantic self-knowledge is associated with episodic self-knowledge in long-term self-knowledge.     

From specific examples to general knowledge in language learning

The extraction of general knowledge from individual episodes is critical if we are to learn new knowledge or abilities. Here we uncover some of the key cognitive mechanisms that characterise this process in the domain of language learning. In five experiments adult participants learned new morphological units embedded in fictitious words created by attaching new affixes (e.g., -afe) to familiar word stems (e.g., “sleepafe is a participant in a study about the effects of sleep”). Participants’ ability to generalise semantic knowledge about the affixes was tested using tasks requiring the comprehension and production of novel words containing a trained affix (e.g., sailafe). We manipulated the delay between training and test (Experiment 1), the number of unique exemplars provided for each affix during training (Experiment 2), and the consistency of the form-to-meaning mapping of the affixes (Experiments 3–5). In a task where speeded online language processing is required (semantic priming), generalisation was achieved only after a memory consolidation opportunity following training, and only if the training included a sufficient number of unique exemplars. Semantic inconsistency disrupted speeded generalisation unless consolidation was allowed to operate on one of the two affix-meanings before introducing inconsistencies. In contrast, in tasks that required slow, deliberate reasoning, generalisation could be achieved largely irrespective of the above constraints. These findings point to two different mechanisms of generalisation that have different cognitive demands and rely on different types of memory representations.     

Unitization of Sublexical Components in Implicit Memory for Novel Words

This study examines the role of componential knowledge and unitization processes in implicit memory. In two experiments, subjects studied novel words formed out of morphemes, syllables, or pseudosyllables. They then completed an implicit task requiring a judgment as to which of two items (one old, one new) was a better English word. Experiment 1 replicated previous results showing priming for nonwords formed out of morphemes and syllables but not seudosyllables. This effect was present when orthographic factors were controlled and, unlike explicit (recognition) memory, was equally strong following visual and semantic processing. Experiment 2 showed that little priming was present across a variety of conditions in which the connections between components were altered across study and test. Results are interpreted as evidence for the role of perceptually based activation and integration processes in implicit memory for novel stimuli.     

Child decision-making: On the burden of predecisional information search

In many decision situations, individuals must actively search information before they can make a satisfying choice. In such instances, individuals must be aware of the fact that not all information may be equally relevant for the choice at hand—thus, individuals should weight information by its respective relevance. We compared children’s and adult’s decision-making in a child-friendly decision game. For each decision, participants received information on the content of 3 piggy banks on an information-board. In Experiment 1, we manipulated the weight-structure by presenting decisions with similarly relevant or differently relevant information. Results suggested that 8- to 9-year-olds did not adapt their search to the weight-structure. In contrast, 10- to 12-year-olds did consider relevance weights. Still, 8- to 9-year-olds and 10- to 12-year-olds were unable to search for a good, adultlike information sample containing all relevant and no irrelevant information. Thus, children based their decisions on a biased information sample. In Experiment 2, we intensified the need to consider relevance weights by introducing a search constraint. In doing so, we replicated the deficits of 8- to 9-year-olds and found adultlike behavior in 11- to 12-year-olds. Our findings suggest that although children understand that relevance may vary, they are not immediately able to effectively consider relevance weights in their information search—which appears to be a skill that continues to develop throughout childhood. We discuss the resulting implications for understanding children as decision makers as well as the general ability to perform structured information search.     

Interactive context integration in children? Evidence from an action memory study

Action–object phrases (e.g., “lift the bottle”) are remembered better if they have been enacted rather than learned verbally. This enactment effect is largest in free recall for phrases with objects (e.g., “bottle”) present because these phrases can be interactively encoded with those context objects (interactive context integration) that serve as retrieval cues. The current study investigated whether 6- and 8-year-olds are already capable of interactive context integration. Experiment 1 demonstrated interactive context integration with 8-year-olds. This was hindered in a condition where attention was directed away from context objects. Experiment 2 demonstrated interactive context integration with 6-year-old kindergartners. Taken together, our findings show that even 6-year-olds are capable of incidental context integration through enactment and that this process is attention based.     

Recognition memory across the adult life span: The role of prior knowledge

Two experiments were performed to investigate the effects of prior knowledge on recognition memory in young adults, younger old adults, 76-year-olds, and 85-year-olds. In Experiment 1, we examined episodic recognition of dated and contemporary famous persons presented as faces, names, and faces plus names. In Experiment 2, four types of faces were presented for later recognition: dated familiar, contemporary familiar, old unfamiliar, and young unfamiliar. The results of both experiments showed that young adults performed better with contemporary than with dated famous persons, whereas the reverse was true for all groups of older adults. In addition, the data of Experiment 2 indicated that (1) young adults showed better recognition for young than for old unfamiliar faces, (2) younger old adults performed better with old than with young unfamiliar faces, and (3) the two oldest age groups showed no effect of age of face. These results suggest that the ability to utilize rich semantic knowledge to improve episodic memory is preserved in very old age, although the aging process may be associated with deficits in the ability to utilize prior knowledge to support memory when the underlying representation lacks semantic and contextual features. The overall data pattern was discussed in relation to the notion that, with increasing adult age, there is an increase in the level of cognitive support required to enhance episodic remembering.     

Children's understanding of inferential knowledge

The understanding of inference as a source of knowledge for 4- and 6-year-old children was investigated. Children and a puppet were shown 2 toys of different colors. The toys were hidden in separate plastic cans. After the puppet looked into 1 of the cans, 6-year-olds, but not 4-year-olds, usually judged that the puppet knew the color of the toy in the other can as well. The finding that 6-year-olds attributed inferential knowledge to another observer is interpreted as evidence that children begin to understand the role of cognitive processes in knowledge acquisition around the age of 6 years.     

Where Hypotheses Come From: Learning New Relations by Structural Alignment

We test whether comparison can promote learning of new relational abstractions. In Experiment 1, preschoolers heard labels for novel spatial patterns and were asked to extend the label to one of two alternatives: one sharing an object with the standard or one having the same relational pattern as the standard. Children strongly preferred the object match when given one standard but were significantly more likely to choose the relational match when they compared two standards. Experiment 2 provided evidence that comparison processing—as opposed to simply seeing two exemplars—is necessary for this relational effect. Preschoolers who were shown the two standards sequentially without a prompt to compare them preferred object matches, as did those who viewed only one standard. In contrast, those who saw the exemplars together, with a prompt to compare them, showed the same elevated relational responding as found in Experiment 1. We suggest that structural alignment processes are crucial to developing new relational abstractions.     

A developmental study of semantic effects on recognition memory

Three experiments evaluated color specificity knowledge and related semantic effects on recognition memory. Experiment I provided the necessary baseline data to show that preschool and college students know the appropriate color of objects. Experiment II revealed semantic effects on recognition of children but not adults. In Experiment III a delay was introduced and adults showed semantic effects as well. The chroma of color-specific and non-color-specific items was remembered relatively well, although chroma recognition for these item types was somewhat different. The semantic effects on very young children's memory suggest deep level interpretive processing in children younger than those generally showing deliberate deployment of memory strategies.     

Young children's (Homo sapiens) understanding of knowledge formation in themselves and others.

Three- and 4-year-old children (Homo sapiens) were tested for comprehension of knowledge formation. In Experiment 1, 34 subjects watched as a surprise was hidden under 1 of 4 obscured cups. The experimenter then pointed to the cup. All children searched under the correct cup, but no 3-year-olds (in contrast to most 4-year-olds) could explain how they knew where to look. Subjects then discriminated between simultaneous pointing by 2 adults, one who had hidden a surprise and one who had left the room before the surprise was hidden. Most 4-year-olds (but no 3-year-olds) showed clear discrimination between the adults. In Experiment 2, 16 subjects were tested with procedures designed to make the source of their own knowledge more obvious, but this had no effect on performance. We conclude that studies using very similar procedures with chimpanzees and rhesus macaques were measuring an ability (or inability) to understand how knowledge states form.     

Semantic and formational clustering in deaf and hearing subjects’ free recall of signs

To investigate whether formational properties of sign language are used spontaneously to organize long-term memory, 16 deaf college students were given a free recall task with items that could be categorized either by shared semantic category or by shared sign language hand shape. Both presentation and response modes (signed or written) were varied between subjects. Analyses revealed no effects of mode on trials to criterion or number of items recalled at 1 week. The clustering that occurred was exclusively semantic, with significantly higher clustering scores during acquisition trials in subjects required to sign their responses. In Experiment 2, formational clustering was encouraged by including formational similarity as the only experimenter-defined basis of categorization, by increasing formational similarity within categories, and by testing only subjects with high signing skills. Input and output modes were again varied between subjects. Subjects were deaf college students with deaf parents (n = 10) or hearing parents (n = 16), and hearing adults with deaf parents (n = 8). Again, spontaneous clustering by formational similarity was extremely low. In only one case— deaf subjects with hearing parents given signed input—did formational clustering increase significantly across the eight acquisition trials. After the categorical nature of the list was explained to subjects at a 1-week retention session, all groups clustered output by formational categories. Apparently, fluent signers do have knowledge of the formational structure of signs, but do not spontaneously use this knowledge as a basis of mnemonic organization in long-term memory.     

Contributions of response set and semantic relatedness to cross-modal Stroop-like picture-word interference in children and adults

Resistance to interference from irrelevant auditory stimuli undergoes development throughout childhood. To test whether semantic processes account for age-related changes in a Stroop-like picture-word interference effect, children (3- to 12-year-olds) and adults named pictures while listening to words varying in terms of semantic relatedness to the pictures and response set membership. In Experiments 1 and 2, with animal and clothing pictures, the interference effect observed in children, but not in adults, depended on the distractors' status as members of the response set. In Experiment 3, with unrelated pictures, adults, but not children, showed greater interference for trials with distractors in the response set. These results indicate developmental changes in picture-word interference involving the establishment of a response set in working memory.