Spoken word recognition and lexical representation in very young children

Although children's knowledge of the sound patterns of words has been a focus of debate for many years, little is known about the lexical representations very young children use in word recognition. In particular, researchers have questioned the degree of specificity encoded in early lexical representations. The current study addressed this issue by presenting 18-23-month-olds with object labels that were either correctly pronounced, or mispronounced. Mispronunciations involved replacement of one segment with a similar segment, as in 'baby-vaby'. Children heard sentences containing these words while viewing two pictures, one of which was the referent of the sentence. Analyses of children's eye movements showed that children recognized the spoken words in both conditions, but that recognition was significantly poorer when words were mispronounced. The effects of mispronunciation on recognition were unrelated to age or to spoken vocabulary size. The results suggest that children's representations of familiar words are phonetically well-specified, and that this specification may not be a consequence of the need to differentiate similar words in production.     

Dominance hierarchies in normal and conduct-disordered children

Two groups of conduct-disordered children in day treatment and two groups of normal matched controls were observed over eight sessions in a free-play situation. The purpose of the study was to examine whether disturbed children formed dominance hierarchies, and to compare the power relations among disturbed children to those of normal peers. Results indicated that the hospitalized children did form dominance hierarchies, although their hierarchies were not as stable as those of their normal peers. Moreover, an inverse relation was noted between intragroup conflict and the hierarchy's stability. In addition, the pattern of targeting differed between the normal and disturbed youngsters. Conflict among the children in both control groups tended to be concentrated among members of adjacent ranks. The disturbed children, on the other hand, were less discriminating as to their target's rank, exhibited greater intragroup conflict, and lost more frequently in their agonistic encounters.     

Effects of perceptual and conceptual similarity in lexical priming of young children who stutter: preliminary findings

The purpose of this study was to investigate the influence of conceptual and perceptual properties of words on the speed and accuracy of lexical retrieval of children who do (CWS) and do not stutter (CWNS) during a picture-naming task. Participants consisted of 13 3–5-year-old CWS and the same number of CWNS. All participants had speech, language, and hearing development within normal limits, with the exception of stuttering for CWS. Both talker groups participated in a picture-naming task where they named, one at a time, computer-presented, black-on-white drawings of common age-appropriate objects. These pictures were named during four auditory priming conditions: (a) a neutral prime consisting of a tone, (b) a word prime physically related to the target word, (c) a word prime functionally related to the target word, and (d) a word prime categorically related to the target word. Speech reaction time (SRT) was measured from the offset of presentation of the picture target to the onset of participant's verbal speech response. Results indicated that CWS were slower than CWNS across priming conditions (i.e., neutral, physical, function, category) and that the speed of lexical retrieval of CWS was more influenced by functional than perceptual aspects of target pictures named. Findings were taken to suggest that CWS tend to organize lexical information functionally more so than physically and that this tendency may relate to difficulties establishing normally fluent speech and language.

Educational objectives: The reader will learn about and be able to (1) communicate the relevance of examining lexical retrieval in relation to childhood stuttering and (2) describe the method of measuring speech reaction times of accurate and fluent responses during a picture-naming task as a means of assessing lexical retrieval skills.     

Testing the abstractness of children's linguistic representations: lexical and structural priming of syntactic constructions in young children

The current studies used a priming methodology to assess the abstractness of children's early syntactic constructions. In the main study, 3-, 4- and 6-year-old children were asked to describe a prime picture by repeating either an active or a passive sentence, and then they were left to their own devices to describe a target picture. For half the children at each age, the prime sentences they repeated had high lexical overlap with the sentence they were likely to produce for the target, whereas for the other half there was very low lexical overlap between prime and target. The main result was that 6-year-old children showed both lexical and structural priming for both the active transitive and passive constructions, whereas 3- and 4-year-old children showed lexical priming only. This pattern of results would seem to indicate that 6-year-old children have relatively abstract representations of these constructions, whereas 3- and 4-year-old children have as an integral part of their representations certain specific lexical items, especially pronouns and some grammatical morphemes. In a second study it was found that children did not need to repeat the prime out loud in order to be primed - suggesting that the priming effect observed concerns not just peripheral production mechanisms but underlying linguistic representations common to comprehension and production. These results support the view that young children develop abstract linguistic representations gradually during the preschool years.     

Dynamic self-organization and early lexical development in children

In this study we present a self-organizing connectionist model of early lexical development. We call this model DevLex-II, based on the earlier DevLex model. DevLex-II can simulate a variety of empirical patterns in children's acquisition of words. These include a clear vocabulary spurt, effects of word frequency and length on age of acquisition, and individual differences as a function of phonological short-term memory and associative capacity. Further results from lesioned models indicate developmental plasticity in the network's recovery from damage, in a non-monotonic fashion. We attribute the network's abilities in accounting for lexical development to interactive dynamics in the learning process. In particular, variations displayed by the model in the rate and size of early vocabulary development are modulated by (a) input characteristics, such as word frequency and word length, (b) consolidation of lexical-semantic representation, meaning-form association, and phonological short-term memory, and (c) delayed processes due to interactions among timing, severity, and recoverability of lesion. Together, DevLex and DevLex-II provide an accurate computational account of early lexical development.     

Conceptual combinations and relational contexts in free association and in priming in lexical decision and naming

Words known to have strong associates of a particular relational type were embedded in lists of other words with relations of the same type or in lists of words with relations of a different type (e.g.close-far in a list of other opposite pairs or in a list of synonym pairs). In free association, the probability of a response consistent with the relational context was higher than the probability of a response inconsistent with the context. In lexical decision and naming, significant priming was obtained for related pairs of words only when their relation was consistent with the relational context of the list in which they were embedded. The priming effects were obtained when the stimulus onset asynchrony between prime and target words was short (250 msec for lexical decision and 300 msec for naming), indicating that the effects were due to automatic retrieval processes. These findings point to the importance of the particular relations between words in the retrieval of information from memory, an aspect of processing overlooked by current memory models.     

A lexical database for spanish-speaking children

This article presents a computerized database of words for use in experimental research in cognitive psychology and psycholinguistics. The data are based on the oral vocabulary of 200 Spanish-speaking children aged from 11.16 to 49.16 months. The database includes 15,428 Spanish words (tokens) and comprises 1,259 different words (types). It provides information about age of acquisition, orthography, grammar, semantics, and frequency.     

Perceptual and lexical components of auditory repetition priming in young and older adults

In the present study, we examined whether age modulates the processing of lexical and perceptual information in auditory implicit and explicit memory tests. Young and older adults performed a surface encoding task on spoken and printed words and then either identified degraded words or made explicit recognition judgments. The implicit test of perceptual identification yielded no evidence of age-related declines in the processing of either lexical information or coarse perceptual details (modality of presentation). The same test, however, produced marked age-related declines in the processing of fine-grained perceptual details (voice) when subjects were not familiarized with the talkers' voices prior to the encoding task. Marked age differences were also observed in recognition memory. These findings suggest that although aging preserves the encoding and incidental retrieval of lexical and coarse perceptual information, it affects the encoding of fine-grained perceptual information and deliberate retrieval processes.     

Auditory lexical decisions in children with specific language impairment

This study examined spoken‐word recognition in children with specific language impairment (SLI) and normally developing children matched separately for age and receptive language ability. Accuracy and reaction times on an auditory lexical decision task were compared. Children with SLI were less accurate than both control groups. Two subgroups of children with SLI, distinguished by performance accuracy only, were identified. One group performed within normal limits, while a second group was significantly less accurate. Children with SLI were not slower than the age‐matched controls or language‐matched controls. Further, the time taken to detect an auditory signal, make a decision, or initiate a verbal response did not account for the differences between the groups. The findings are interpreted as evidence for language‐appropriate processing skills acting upon imprecise or underspecified stored representations.     

Early lexical development in children with focal brain injury

Early lexical development in 27 children with focal brain injury was studied cross-sectionally and longitudinally. Data were obtained from children between 12 and 35 months of age who acquired their lesion prenatally or within the first 6 months of life. Results for the group as a whole provide clear evidence for delays in lexical comprehension and production, and for a larger number of comprehension/production dissociations than would be expected by chance. In addition, a significant number of children were observed having unusual difficulty mastering predication and/or using an atypically high proportion of closed class words (suggesting reliance on holistic/formulaic speech). Analyses by lesion type revealed no effect of lesion size. Analyses according to side of lesion revealed that children with right-hemisphere damage produced a higher proportion of closed class words, suggesting heavy reliance on well-practiced but under-analyzed speech formulae. Children with left-hemisphere damage were slightly better in comprehension than children with right-hemisphere damage. In addition, left posterior lesions were associated with greater delays in expressive language, and delays were more protracted in children with left posterior damage. No differential effects of left posterior damage were found for lexical comprehension.     

Age-of-acquisition differences in young and older adults affect latencies in lexical decision and semantic categorization

An ongoing discussion about the role of age of acquisition (AoA) in word processing concerns the confound with word frequency. This study removed possible frequency confounds by comparing AoA and word familiarity differences in young (18-23 years) and older (52-56 years) adults. A first study investigated the differences in AoA and word familiarity ratings. The norms of AoA and familiarity were significantly different for young and older adults whereas these were previously considered equivalent [Morrison, C. M., Hirsh, K. W., Chappell, T., & Ellis, A. W. (2002). Age and age of acquisition: An evaluation of the cumulative frequency hypothesis. European Journal of Cognitive Psychology, 14, 435-459]. In the second study, AoA and familiarity effects were significantly different for the older and young adults in a lexical decision task. The third study replicated these findings in a semantic artifact/naturally occurring categorization experiment, thus providing further evidence for AoA-effects when word processing requires semantic mediation. Results from both studies were in line with the hypothesis that AoA effects on word processing cannot be accounted for by word frequency or other possible confounds.     

The effect of lexical frequency on spoken word recognition in young and older listeners

When identifying spoken words, older listeners may have difficulty resolving lexical competition or may place a greater weight on factors like lexical frequency. To obtain information about age differences in the time course of spoken word recognition, young and older adults' eye movements were monitored as they followed spoken instructions to click on objects displayed on a computer screen. Older listeners were more likely than younger listeners to fixate high-frequency displayed phonological competitors. However, degradation of auditory quality in younger listeners does not reproduce this result. These data are most consistent with an increased role for lexical frequency with age.     

Productivity of lexical categories in French-speaking children with cochlear implants

The productivity of lexical categories was studied longitudinally in a sample of 17 young hearing-impaired French-speaking children with cochlear implants. Age of implantation ranged from 22 months to 76 months. Spontaneous speech samples were collected at six-month intervals over a period of 36 months, starting at the one-word stage. Four general measures of their linguistic production (number of utterances, verbal fluency, vocabulary, and grammatical production) as well as 36 specific lexical categories, according to the CHILDES codes, were computed in terms of tokens, i.e., total number of words. Cochlear-implanted children (CI) were compared to a French database of normally hearing children aged 2-4 compiled by the first author. Follow-up results indicate that, at the two-year post-implantation follow-up, noun, and verb morphology was significantly impaired. At the three-year follow-up, the cochlear-implanted group had recovered on adjectives, determiners and nouns, main verbs, and auxiliaries. The two groups differed significantly in processing locative adverbs, prepositions, pronouns, and verbs (infinitive verb, modal, and modal lexical), but individual variability within the cochlear-implanted group was substantial. Results are discussed in terms of recovery and developmental trends and variability in the acquisition of lexical categories by French children two years and three years post-implantation.     

Conceptual elaboration versus direct lexical access in WAIS-similarities: differential effects of white-matter lesions and gray matter volumes

Wechsler Adult Intelligence Scale (WAIS) subscale Similarities have been classified as a test of either verbal comprehension or of inductive reasoning. The reason may be that items divide into two categories. We tested the hypothesis of heterogeneity of items in WAIS-Similarities. Consecutive patients at a memory clinic and healthy controls participated in the study. White-matter hyperintensities (WMHs) and normalized temporal lobe volumes were measured based on Magnetic resonance Imaging (MRI), and tests of verbal memory and attention were used in addition to WAIS-Similarities to collect behavioural data. Factor analysis supported the hypothesis that two factors are involved in the performance of WAIS-similarities: (1) semiautomatic lexical access and (2) conceptual elaboration. These factors were highly correlated but provided discriminative diagnostic information: In logistic regression analyses, scores of the lexical access factor and of the conceptual elaboration factor discriminated patients with mild cognitive impairment from Alzheimer’s disease patients and from healthy controls, respectively. High scores of WMH, indicating periventricular white-matter lesions, predicted factor scores of direct lexical access but not those of conceptual elaboration, which were predicted only by medial and lateral temporal lobe volumes.     

Early lexical development of children raised in institutional care in Russia

Children abandoned to institutions display a host of developmental delays, including those involving general cognition and language. The majority of published studies focus on children over 3 years of age; little is known about whether these delays may be detected earlier when children undergo rapid lexical development. To investigate the early language development of children raised in institutional settings in the Russian Federation, we compared a group of children in institutional care (n = 36; 8–35 months) to their age-matched peers raised in biological families, who have never been institutionalized (n = 72) using the Russian version of the CDI. The results suggest that institutionalization is associated with pronounced delays in children's early language development with large and robust effect sizes. Among children with a history of institutionalization, these delays are also associated with difficulties in Daily Living skills, communication, and socialization.     

Collaboration in young children

Humans accomplish much of what they do in collaboration with others. In ontogeny, children's earliest abilities to collaborate develop in two basic steps. First, 1- and 2-year-olds learn to form with others joint goals and joint attention--which include an understanding of the individual roles and perspectives involved. Second, as they approach their third birthdays, children's collaborative interactions with others take on a more normative dimension involving obligations to the partner. In addition, their cognitive abilities to conceptualize simultaneously both their own role and perspective along with those of the other develop considerably as well. This form of collaborative interaction is underlain by species-unique skills and motivations for shared intentionality that make possible, ultimately, such things as complex cultural institutions.     

Affect and memory in young children

The state-dependent theory of the relationship between affective states and memory holds that recall will be best when the affective state at recall matches that during learning. Sequential happy, neutral, and sad affective states that were either consistent (e.g., Happy-Happy) or inconsistent (e.g., Sad-Neutral) were experimentally induced in preschool children prior to encoding and then again prior to retrieval (free and cued recall, recognition memory). Facial ratings indicated that the inductions were effective in inducing affect. Nevertheless, emotional states did not influence children's ability to recall items under free or cued conditions, and recognition memory was essentially perfect for all subjects. Thus, there was no evidence for state-dependent learning or for a positive loop between subjects' positive affect at retrieval and memory for positively rated information. Results are discussed in terms of the generally inconsistent findings in the literature on the role of affect in children's memory and factors that may limit affective state-dependent learning in children.This research was supported by Research Grant No. 11776 from the National Institute of Child Health and Human Development to Marion Perlmutter, by Grant BNS 78-01108 from the National Science Foundation to John C. Masters, and by Program Project Grant No. 0527 to the Institute of Child Development. Wayne Duncan is now at the University of Denver, and Christine Todd is now at the University of Illinois, Urbana. Marion Perlmutter is now at the University of Michigan. We would like to thank Keith Elliott and LuAnne Tczap for their work as experimenters; Jule Kogan, Carol Revermann, and Sonya Hernandez for their help in coding data; and Jayne Grady-Reitan for her administrative assistance throughout the study.