Young children's use of range-of-reference information in word learning

An important source of information about a new word's meaning (and its associated lexical class) is its range of reference: the number of objects to which it is extended. Ninety toddlers (mean age = 37 months) participated in a study to determine whether young children can use this information in word learning. When a novel word was presented with unambiguous lexical class cues as either a proper name (i.e. 'His name is DAXY') or an adjective (i.e. 'He is very DAXY'), toddlers interpreted it appropriately, regardless of whether it was applied to one or both members of a pair of identical-looking stuffed animals. They restricted a proper name to the designated animal(s); but they generalized an adjective from the labeled animal(s) to a new animal bearing the same property. However, when the word was presented with no specific lexical class cues (i.e. 'DAXY'), toddlers made significantly different interpretations, depending on the number of referents. When the word was applied to one animal, they restricted it to that animal (consistent with a proper name interpretation); when the word was applied to two animals, they generalized it to a new animal with the property (consistent with an adjective or a restricted count noun interpretation). Range-of-reference information thus provided toddlers with a default cue to the meaning (and associated lexical class) of a novel word.     

The cradle of categorization: Is the basic level basic?

A common assumption in the developmental literature is that the earliest kind of conceptual categories to be formed are basic-level categories. A corollary assumption is that superordinate categories are formed after, and out of, previously acquired basic-level categories. Two experiments using an object-manipulation task explored these assumptions by studying response to a variety of categories in children aged from 12 to 20 months. The first experiment examined responses to basic-level categories (dogs vs. cars),superordinate categories (animals vs. vehicles), and contextual categories (kitchen things vs. bathroom things). At all ages tested, the children performed best on the basic-level categories but, even at 12 months of age, some children were responsive to the superordinate and contextual categories. By 20 months of age, approximately half of the children showed such sensitivity. The second experiment showed that 16- and 20-month-olds differentiated basic-level categories only when the categorical contrasts were taken from different superordinate classes (e.g., dogs vs. cars) and not when the categories were drawn from the same superordinate class (e.g., dogs vs. horses). The data suggest that basic-levels categories are not the first kind of conceptual categories to be formed. Instead, it appears that children may form more global categories, with basic-level differentiation occurring later.     

So many options,so little control: Abstract representations can reduce selection demands to increase children’s self-directed flexibility

Children often struggle to behave flexibly when they must use self-directed goals (e.g., doing homework without prompting) rather than externally driven goals (e.g., cleaning up when told). Such struggles may reflect the demands of selecting among many potential options, as required for self-directed control. The current study tested whether (a) 6-year-old children show difficulty in selecting among competing semantic representations, (b) providing category labels designed to reduce selection demands improves performance, and (c) such benefits transfer to self-directed flexibility. Selection was measured using the blocked cyclic naming task for the first time with children. Pictures were named repeatedly in either homogeneous blocks from the same category (e.g., all animals), which create high selection demands due to spreading semantic activation and engage effortful cognitive control, or mixed blocks with each picture from a different category. Children showed robust difficulty in selecting among options, as indexed by response time (RT) differences between homogeneous and mixed blocks. Providing subcategory labels designed to reduce selection demands by distinguishing among same-category items (e.g., “A cow is a farm animal. A cat is a pet.”) improved selection. Providing superordinate categories (e.g., “A cow is an animal. A cat is an animal.”) also improved selection, but these benefits were less robust, and subcategory labels led to greater benefits than superordinate category labels on a subsequent verbal fluency task. These results support a role for subcategory representations in reducing selection demands to aid self-directed flexibility while suggesting that some children may use superordinate category labels to activate subcategory representations on their own.     

Can Toddlers Learn Vocabulary from Television? An Experimental Approach

This study was inspired by the rise in television targeting toddlers and preverbal infants (e.g., Teletubbies, Baby Mozart). Overall, we investigated if very young children who are in the early stages of language acquisition can learn vocabulary quickly (fast map) from television programs. Using a fast mapping paradigm, this study examined a group (n = 48) of toddlers (15–24 months) and their ability to learn novel words. Utilizing a repeated measures design, we compared children's ability to learn various novel words in 5 different conditions. These included the presentation and identification of a novel word by an adult speaker via live presentation when the toddler was attending (i.e., joint reference), an adult via live presentation when the toddler was not attending, an adult speaker on television, and an edited clip from a children's television program (Teletubbies). Overall, the toddlers were most successful in learning novel words in the joint reference condition. They were significantly less successful in the children's program condition. Furthermore, there was a significant interaction between age and condition on children's performance. Both younger (15–21 months) and older (22–24 months) participants identified the target objects when they were taught the novel word by an adult speaker; however, it appeared that children under the age of 22 months did not identify the target item when they were taught the novel word via the television program.     

Evidence in support of word unitization

In each of five experiments, the subjects viewed tachistoscopically presented pairs of letters and made speeded comparison judgments on the basis of name identity. On most trials, a noise letter string (word or anagram) was placed directly between the target letters. The results indicated that correct “same” RTs were a function of noise item type and its relation to target letters. Anagrams increased RTs more than their counterpart words, except when the noise word was either unmeaningflul or response incompatible with respect to the target letters (e.g., B Tea b). The interference effects were also found to be independent of sequence length. It was posited that the subjects were unable to completely ignore the irrelevant attributes of the displays and that under certain conditions, the subjects were able to identify the noise items in a holistic fashion. The data were interpreted in terms of a unitization hypothesis of word recognition, response competition, and a continuous-flow conception of information processing.     

Unconscious vision spots the animal but not the dog: Masked priming of natural scenes

The functional role of consciousness has been traditionally assumed to be related to high-level executive functions, but recent theories of visual consciousness suggest qualitative differences between conscious and unconscious processes also in lower level visual processes. We tested how specific is the information that can be extracted by unconscious processes from natural scenes. Prime images which were suppressed from consciousness by continuous flash suppression facilitated categorization of visible targets at superordinate level (animal vs. non-animal) when the prime shared a category membership with the target. Suppressed prime images did not have any effect on categorization at the basic level (e.g., horse vs. other animal). Priming occurred at basic level categorization only when the prime images were available to consciousness. This pattern supports a “coarse-to-fine” model in which the visual system can unconsciously access coarse representations, but consciousness is needed for finer analysis of visual scenes.     

The crucial roles of stimulus matching and stimulus identity in negative priming

Negative priming refers to the situation in which an ignored item on an initial prime trial suffers slowed responding when it becomes the target item on a subsequent probe trial. In this experiment (and a replication), we demonstrate two ways in which stimulus consistency (matching) governs negative priming. First, negative priming for identical words occurred only when the prime distractor changed color when it became the probe target (i.e., constant cue to read the red word); negative priming disappeared when the prime distractor retained its color as the probe target (i.e., cue switches from read the red prime word to read the white probe word). Second, negative priming occurred for identical words, but not for semantically related words, whether related categorically or associatively. This pattern of results is consistent with a memory retrieval account, but not with an inhibition account of negative priming, and casts doubt on whether there is semantic negative priming for words.     

An associative account of the development of word learning

Word learning is a notoriously difficult induction problem because meaning is underdetermined by positive examples. How do children solve this problem? Some have argued that word learning is achieved by means of inference: young word learners rely on a number of assumptions that reduce the overall hypothesis space by favoring some meanings over others. However, these approaches have difficulty explaining how words are learned from conversations or text, without pointing or explicit instruction. In this research, we propose an associative mechanism that can account for such learning. In a series of experiments, 4-year-olds and adults were presented with sets of words that included a single nonsense word (e.g. dax). Some lists were taxonomic (i.,e., all items were members of a given category), some were associative (i.e., all items were associates of a given category, but not members), and some were mixed. Participants were asked to indicate whether the nonsense word was an animal or an artifact. Adults exhibited evidence of learning when lists consisted of either associatively or taxonomically related items. In contrast, children exhibited evidence of word learning only when lists consisted of associatively related items. These results present challenges to several extant models of word learning, and a new model based on the distinction between syntagmatic and paradigmatic associations is proposed.     

Hierarchical categorization by bilingual Latino children: does a basic-level bias exist?

Research has shown that children classify most easily at the basic level where objects in the same category look similar enough to each other to be grouped together but are distinct enough from objects in other categories to be discriminated (e.g., animal/bird/duck). In this article, the authors report on 2 experiments they conducted to determine whether children maintain this basic category bias when the perceptual similarity of stimuli at different hierarchical levels is equalized. Pictures within and across 3 hierarchical levels were made perceptually equivalent and shown to 71 Latino children who were bilingual in Spanish and English. In Experiment 1, the pictures used as exemplars could be categorized on any of the 3 hierarchical levels. In Experiment 2, example pictures unambiguously defined the level of categorization that would be accurate, and linguistic cues were given that might assist in the selection of the correct category. In both experiments, the children sorted pictures from all 3 levels equally well, but they found it harder to justify their sorting of superordinate pictures. English competence predicted sorting on the more ambiguous sorting task in Experiment 1; and English competence predicted verbal justifications in both experiments, even though the experiments were conducted in Spanish. Competence in Spanish or English was an equally good predictor of sorting in the better defined sorting task in Experiment 2. These findings indicate that a superordinate level deficiency remains after perceptual differences are eliminated and that the deficiency is cognitive in nature. Differences in the performances of children who differed in bilingualism support the hypothesis that a threshold of proficiency in both languages is an important determinant of the effect of bilingualism on categorization.     

Teaching effective hand raising to children with autism during group instruction

We taught 3 children with autism to raise a hand or keep both hands down depending on their status (e.g., having heard a target word, possessing a specific item) using modeling, prompting, and reinforcement. All 3 children acquired accurate hand-raising skills in response to progressively more difficult discrimination tasks during group instruction. The implications for preparing children for general education settings are discussed.     

发展性阅读障碍儿童阅读中的眼跳定位缺陷：基于新词学习的实验证据

通过与生理年龄匹配儿童比较新词重复学习中眼跳定位模式变化的异同, 探讨发展性阅读障碍儿童在新词学习中的眼跳定位是否存在缺陷。以发展性阅读障碍儿童和生理年龄匹配儿童为被试, 采用重复学习新词范式, 结果发现：(1)与生理年龄匹配组相比, 发展性阅读障碍儿童跳入新词的眼跳距离较短、首次注视落点位置更靠近词首; (2)生理年龄匹配组儿童利用学习次数调节新词眼跳定位模式的能力高于发展性阅读障碍儿童, 即随着新词学习次数的增加, 生理年龄匹配组儿童跳入和跳出新词的眼跳距离随之增长, 首次注视落点位置更靠近词中心; 相比之下, 发展性阅读障碍儿童仅在跳出新词的眼跳距离上有所增长, 但增加幅度也显著小于生理年龄匹配组。结果表明, 发展性阅读障碍儿童在新词学习中的眼跳定位, 及利用学习次数对眼跳定位的调节上均表现出一定缺陷。     

THE INFLUENCE OF MOTIVATING OPERATIONS ON GENERALIZATION PROBES OF SPECIFIC MANDS BY CHILDREN WITH AUTISM

We investigated the influence of motivating operations on the generalization of newly taught mands across settings and communication partners for 3 children with autism. Two conditions were implemented prior to generalization probes. In the first condition, participants were given access to a preferred item until they rejected the item (i.e., abolishing operation). In the second condition, the item was not available to participants prior to generalization probes (i.e., establishing operation). The effects of these conditions on the generalization of newly taught mands were evaluated in a multielement design. Results indicated differentiated responding during generalization probes in which more manding with the target mand was observed following the presession no‐access condition than in the presession access condition. These results support the consideration of motivating operations when assessing generalization of target mands to various untrained contexts.     

Origine de l’effet longueur de mots en mémoire à court terme verbale chez l’enfant

The current study investigated the determinants of the word length effect in five-, seven-, and nine-year-old children building on Henry (Q J Exp Psychol 43A (1991a) 35-52) previous work. Henry postulated that the word length effect observed in children was caused by verbal output and not rehearsal. Children were given an immediate serial recall task where full verbal recall is required and an immediate probed recall task where only one of the items has to be recall (the item indicated by the experimenter). In the probed recall task, the spatial probe previously used by Henry and criticized by Gathercole and Hitch (Gathercole, S.E., Hitch, G.J., 1993. Developmental Changes in Short-Term Memory: a Revised Working Memory Perspective. In: Collins A. F., Gathercole S. E., Conway M. A., Morris P. E. (Eds.), Theories of Memory. Lawrence Erlbaum Associates, Hove, pp. 189-209) was changed for a pure verbal probe. Our results indicated that 5-, 7-, and 9-year-old children were sensitive to words length when full verbal recall was required. On the contrary, word length effects were not found in five-, seven-, and nine-year-old children when recall was restricted to just one item. These results lend further support to Henry's hypothesis suggesting that the word length effect operates at recall time, through output delay.     

Children's use of “extra-list” cues to retrieve theme and category episodic information from memory

The ability of second- and fifth-grade children and college adults to use “extra-list” cues to retrieve episodic information from memory was examined in four experiments. The acquisition events were word triplets characterized by category relations (i.e., Rose-Tulip-Lily), theme cooccurrence relations (i.e., Bunny-Jelly Beans-Lily), or no relevant conceptual relation (i.e., Wood-Brick-Lily) among the triplet members, and event classification was ensured by means of an acquisition orienting question. Cued recall for the target (i.e., Lily) was assessed for extra-list Class Name cues (Flower or Easter) in Experiments 1 and 3, and Class Associate cues in Experiments 2 and 4. The classifications concerned superordinate category versus theme cooccurrence relations in Experiments 1 and 2, subordinate versus superordinate category relations in Experiment 3, and prototypical versus nonprototypical associates in Experiment 4. The results showed that effective cue use varied strongly with both the “match” of cue and event class information, and with the associative structure of permanent memory. Probable differences in this structure seem to contribute to both inherent and developmental differences in using cues to retrieve theme or category episodic information.     

Children learn words easier when they are interested in the category to which the word belongs

The overall pattern of vocabulary development is relatively similar across children learning different languages. However, there are considerable differences in the words known to individual children. Historically, this variability has been explained in terms of differences in the input. Here, we examine the alternate possibility that children's individual interest in specific natural categories shapes the words they are likely to learn – a child who is more interested in animals will learn a new animal name easier relative to a new vehicle name. Two‐year‐old German‐learning children (N = 39) were exposed to four novel word–object associations for objects from four different categories. Prior to the word learning task, we measured their interest in the categories that the objects belonged to. Our measure was pupillary change following exposure to familiar objects from these four categories, with increased pupillary change interpreted as increased interest in that category. Children showed more robust learning of word–object associations from categories they were more interested in relative to categories they were less interested in. We further found that interest in the novel objects themselves influenced learning, with distinct influences of both category interest and object interest on learning. These results suggest that children's interest in different natural categories shapes their word learning. This provides evidence for the strikingly intuitive possibility that a child who is more interested in animals will learn novel animal names easier than a child who is more interested in vehicles.     

On time differences in searching for letters in words and nonwords: Do they emerge during the initial encoding or the subsequent scan?

Krueger (1970a, 1970b, 1982) has demonstrated that subjects can search for target letters within words faster than they can complete an equivalent search through nonwords, and he further demonstrated that the effect did not arise during the comparison stage. The present study involved three experiments in which the usual word advantage disappeared either when subjects knew where within a display the target item would appear (i.e., it was always the first letter), or when all the component letters were encoded into memory before the task began (i.e., a memory-search task). These data, in conjunction with Krueger's, where interpreted as localizing at least one (and possibly the only) source of the word-nonword difference in this task to the events that occur during the item-to-item transitions subjects make when scanning the letter arrays. That is, these transitions are faster for words than nonwords, and it was suggested that the time difference may emerge because although all the letters from within a word appear to be available in memory before the scan begins, this seems not to be true for consonant arrays. Given that this is the case, part of the word-nonword difference may be attributable to subsequent encoding events that would be needed for the consonant arrays as the scan moves from letter to letter.     

Comparison in the Development of Categories

Recent research on children's word learning has led to a paradox. Although word learning appears to be a deep source of insight into conceptual knowledge for children, preschoolers often categorize objects on the basis of shallow perceptual features such as shape. The current studies seek to resolve this discrepancy. We suggest that comparing multiple instances of a category enables children to extract deeper relational commonalities among category members. We examine 4-year-olds' categorization behaviors when asked to select a match for a target object (e.g., an apple) between a perceptually similar, out-of-kind object (e.g., a balloon) and a perceptually different category match (e.g., a banana). Children who learn a novel word as a label for multiple instances of the category are more likely to select the category match over the perceptual match. Children who learn a label for only one instance are equally likely to select either alternative. This effect is present even when individual target instances are more perceptually similar to the perceptual choice than to the category choice. We conclude that structural alignment processes may be important in the development of category understanding.