The competition–compensation account of developmental language disorder

Children with developmental language disorder (DLD) regularly use the bare form of verbs (e.g., dance) instead of inflected forms (e.g., danced). We propose an account of this behavior in which processing difficulties of children with DLD disproportionally affect processing novel inflected verbs in their input. Limited experience with inflection in novel contexts leads the inflection to face stronger competition from alternatives. Competition is resolved through a compensatory behavior that involves producing a more accessible alternative: in English, the bare form. We formalize this hypothesis within a probabilistic model that trades off context-dependent versus independent processing. Results show an over-reliance on preceding stem contexts when retrieving the inflection in a model that has difficulty with processing novel inflected forms. We further show that following the introduction of a bias to store and retrieve forms with preceding contexts, generalization in the typically developing (TD) models remains more or less stable, while the same bias in the DLD models exaggerates difficulties with generalization. Together, the results suggest that inconsistent use of inflectional morphemes by children with DLD could stem from inferences they make on the basis of data containing fewer novel inflected forms. Our account extends these findings to suggest that problems with detecting a form in novel contexts combined with a bias to rely on familiar contexts when retrieving a form could explain sequential planning difficulties in children with DLD.

Research Highlights

• Generalization difficulties with inflectional morphemes in children with Developmental Language Disorder arise from these children's limited experience with novel inflected forms.
• Limited experience with a form in novel contexts could lead to a storage bias where retrieving a form often requires relying on familiar preceding stems.
• While generalization in typically developing models remains stable across a range of model parameters, certain parameter values in the impaired models exaggerate difficulties with generalization.
• Children with DLD compensate for these retrieval difficulties through accessibility-driven language production: they produce the most accessible form among the alternatives.

     

An experimental approach to language training in second language acquisition: Focus on negation

The effect of negation training in a second language on the expression of negation in the native language was investigated. Four-year-old children from bilingual (Spanish/English) homes who showed no expressive or receptive ability in Spanish negation and were either proficient or nonproficient in English negation received Spanish negation training. Children who were proficient in English negation maintained correct responses in English and showed increased correct responses in Spanish following simultaneous training in both languages or in Spanish alone. Children who were nonproficient in English negation demonstrated a decrease in correct English responses following training in Spanish alone; however, children who received training in English and Spanish simultaneously showed increases in correct responses in both languages. These findings suggest that language training programs with children learning a second language should consider the relationship of the two language training conditions (simultaneous vs. independent) with the child's level of native language proficiency.     

Inside bilingualism: Language background modulates selective attention to a talker's mouth

Previous findings indicate that bilingual Catalan/Spanish‐learning infants attend more to the highly salient audiovisual redundancy cues normally available in a talker's mouth than do monolingual infants. Presumably, greater attention to such cues renders the challenge of learning two languages easier. Spanish and Catalan are, however, rhythmically and phonologically close languages. This raises the possibility that bilinguals only rely on redundant audiovisual cues when their languages are close. To test this possibility, we exposed 15‐month‐old and 4‐ to 6‐year‐old close‐language bilinguals (Spanish/Catalan) and distant‐language bilinguals (Spanish/”other”) to videos of a talker uttering Spanish or Catalan (native) and English (non‐native) monologues and recorded eye‐gaze to the talker's eyes and mouth. At both ages, the close‐language bilinguals attended more to the talker's mouth than the distant‐language bilinguals. This indicates that language proximity modulates selective attention to a talker's mouth during early childhood and suggests that reliance on the greater salience of audiovisual speech cues depends on the difficulty of the speech‐processing task.     

Repetition priming within and between languages in verb generation: Evidence for shared verb concepts

Although translation equivalents for concrete nouns are known to have shared core conceptual representations in bilingual memory (Francis, 1999), the status of translation-equivalent verbs has not been systematically tested. Three repetition-priming experiments using a verb generation task were used to determine whether verbs have shared representations across languages and to identify the processes facilitated in repeated verb generation. In Experiment 1 fluent Spanish–English bilingual speakers exhibited repetition priming both within and between languages, but between-language priming was weaker. In Experiment 2 performance of non-bilingual English and Spanish speakers was equivalent to that of bilingual speakers responding in their dominant language. Experiment 3 used manipulations meant to isolate noun comprehension, verb concept selection, and verb production. The between-language priming in Experiments 1 and 3 indicates that verb concepts are shared across languages and that verb concept selection exhibits facilitation. Experiment 3 showed that the greater within-language priming was due primarily to facilitation of verb production processes.     

Language‐dependent memory in bilingual learning

Spanish‐English bilinguals were taught academic‐type information about History, Biology, Chemistry and Mythology in their two languages. Upon testing, it was found that memory was more accurate and retrieval was faster when the language of retrieval and the language of encoding matched than when they did not match. For accuracy, the pattern of results was influenced by bilinguals' language proficiency, so that only balanced bilinguals whose high proficiency levels were similar in both languages showed language‐dependent recall. For reaction time, bilinguals were faster to retrieve information when the languages of retrieval and encoding matched than when they mismatched, but only for material encoded in Spanish. The influence of encoding and retrieval languages on error patterns was also examined. Together, the study's findings suggest that bilingual learning may be subject to language dependency and that experience with a language may increase the strength of linguistic cues in producing language‐dependent memory. The results are consistent with previous findings of language‐dependent memory in autobiographical narratives, carry applied implications for bilingual education, and are discussed within the theoretical framework of the relationship between language and memory. Copyright © 2006 John Wiley & Sons, Ltd.     

Modeling the Developmental Patterning of Finiteness Marking in English, Dutch, German, and Spanish Using MOSAIC

In this study, we apply MOSAIC (model of syntax acquisition in children) to the simulation of the developmental patterning of children's optional infinitive (OI) errors in 4 languages: English, Dutch, German, and Spanish. MOSAIC, which has already simulated this phenomenon in Dutch and English, now implements a learning mechanism that better reflects the theoretical assumptions underlying it, as well as a chunking mechanism that results in frequent phrases being treated as 1 unit. Using 1, identical model that learns from child-directed speech, we obtain a close quantitative fit to the data from all 4 languages despite there being considerable cross-linguistic and developmental variation in the OI phenomenon. MOSAIC successfully simulates the difference between Spanish (a pro-drop language in which OI errors are virtually absent) and obligatory subject languages that do display the OI phenomenon. It also highlights differences in the OI phenomenon across German and Dutch, 2 closely related languages whose grammar is virtually identical with respect to the relation between finiteness and verb placement. Taken together, these results suggest that (a) cross-linguistic differences in the rates at which children produce OIs are graded, quantitative differences that closely reflect the statistical properties of the input they are exposed to and (b) theories of syntax acquisition need to consider more closely the role of input characteristics as determinants of quantitative differences in the cross-linguistic patterning of phenomena in language acquisition.     

Acquiring and processing verb argument structure: distributional learning in a miniature language

Adult knowledge of a language involves correctly balancing lexically-based and more language-general patterns. For example, verb argument structures may sometimes readily generalize to new verbs, yet with particular verbs may resist generalization. From the perspective of acquisition, this creates significant learnability problems, with some researchers claiming a crucial role for verb semantics in the determination of when generalization may and may not occur. Similarly, there has been debate regarding how verb-specific and more generalized constraints interact in sentence processing and on the role of semantics in this process. The current work explores these issues using artificial language learning. In three experiments using languages without semantic cues to verb distribution, we demonstrate that learners can acquire both verb-specific and verb-general patterns, based on distributional information in the linguistic input regarding each of the verbs as well as across the language as a whole. As with natural languages, these factors are shown to affect production, judgments and real-time processing. We demonstrate that learners apply a rational procedure in determining their usage of these different input statistics and conclude by suggesting that a Bayesian perspective on statistical learning may be an appropriate framework for capturing our findings.     

Effects of past language experience and present language context on the shape bias in Spanish–English bilingual children

English‐monolingual children develop a shape bias early in language acquisition, such that they more often generalize a novel label based on shape than other features. Spanish‐monolingual children, however, do not show this bias to the same extent (Hahn & Cantrell, 2012). Studying children who are simultaneously learning both Spanish and English presents a unique opportunity to further investigate how this word‐learning bias develops. Thus, we asked how Spanish–English bilingual children (M_age = 21.31 months) perform in a novel‐noun generalization (NNG) task, specifically examining how past language experience (i.e. language exposure and vocabulary size) and present language context (i.e. whether the NNG task was conducted in Spanish or English) influence the strength of the shape bias. Participants completed the NNG task either entirely in English (N = 16) or entirely in Spanish (N = 16), as well as language understanding tasks in both English and Spanish to ensure that they understood what the experimenter was asking them to do. Parents completed a language exposure survey and vocabulary checklists in Spanish and English. There was a significant interaction between condition and choice type: Bilingual children in the English condition showed a shape bias in the NNG task, but bilingual children in the Spanish condition showed no reliable biases. No measures of past language experience were related to NNG task performance. These results suggest that when learning new words, bilingual children are attuned to the regularities of the present language context, and prior language experiences may play a more secondary role.     

Attention to Explicit and Implicit Contrast in Verb Learning

Contrast information could be useful for verb learning, but few studies have examined children's ability to use this type of information. Contrast may be useful when children are told explicitly that different verbs apply, or when they hear two different verbs in a single context. Three studies examine children's attention to different types of contrast as they learn new verbs. Study 1 shows that 3.5-year-olds can use both implicit contrast (“I'm meeking it. I'm koobing it.”) and explicit contrast (“I'm meeking it. I'm not meeking it.”) when learning a new verb, while a control group's responses did not differ from chance. Study 2 shows that even though children at this age who hear explicit contrast statements differ from a control group, they do not reliably extend a newly learned verb to events with new objects. In Study 3, children in three age groups were given both comparison and contrast information, not in blocks of trials as in past studies, but in a procedure that interleaved both cues. Results show that while 2.5-year-olds were unable to use these cues when asked to compare and contrast, by 3.5 years old, children are beginning to be able to process these cues and use them to influence their verb extensions, and by 4.5 years, children are proficient at integrating multiple cues when learning and extending new verbs. Together these studies examine children's use of contrast in verb learning, a potentially important source of information that has been rarely studied.     

汉语母语者英语动词三种屈折变化形式加工机制的差异

采用ERP技术考察了汉语母语者,英语动词三种屈折变化形式加工机制的差异。结果发现,英语动词进行式的屈折变化形式- ing的错误使用诱发了P600成分;完成式的屈折变化形式- ed的错误使用诱发了N400成分;完成式中没有明显屈折变化标识的不规则词的错误使用没有诱发典型的ERP成分。研究结果表明：对于缺乏英语使用环境、母语为汉语的晚期英语学习者来说,屈折变化形式- ing,完成式规则动词的变化形式- ed和没有明显形态变化标识的不规则动词的变化形式具有不同的加工机制,前者可能处于由陈述性记忆系统向程序性记忆系统加工的转变过程中,而后两者更多地由陈述性系统进行加工。这种加工机制的差异可能与动词屈折变化规则的复杂程度有关。     

Language-specific Knowledge and Short-term Memory in Bilingual and Non-bilingual Children

The sensitivity of children's phonological short-term memory performance to languagespecific knowledge was investigated in two experiments. In Experiment 1, monolingual English children, English-French bilingual children, and English children who were learning French as a second language were compared on measures of phonological short-term memory and vocabulary in the two languages. The children's short-term memory performance in each language mirrored their familiarity with English and French, with greater vocabulary knowledge being associated with higher levels of recall of both words and nonwords in that language. This finding was replicated in Experiment 2, in which two groups of children with good knowledge of English and French were examined: native bilingual children who had comparable knowledge of the two languages and non-native bilingual children who had a greater knowledge of their native than second language. The findings indicate that phonological short-term memory is not a language-independent system but, rather, functions in a highly language-specific way.     

The Relationship Between Artificial and Second Language Learning

Artificial language learning (ALL) experiments have become an important tool in exploring principles of language and language learning. A persistent question in all of this work, however, is whether ALL engages the linguistic system and whether ALL studies are ecologically valid assessments of natural language ability. In the present study, we considered these questions by examining the relationship between performance in an ALL task and second language learning ability. Participants enrolled in a Spanish language class were evaluated using a number of different measures of Spanish ability and classroom performance, which was compared to IQ and a number of different measures of ALL performance. The results show that success in ALL experiments, particularly more complex artificial languages, correlates positively with indices of L2 learning even after controlling for IQ. These findings provide a key link between studies involving ALL and our understanding of second language learning in the classroom.     

Repetition priming within and between languages in verb generation: evidence for shared verb concepts

Although translation equivalents for concrete nouns are known to have shared core conceptual representations in bilingual memory (Francis, 1999), the status of translation-equivalent verbs has not been systematically tested. Three repetition-priming experiments using a verb generation task were used to determine whether verbs have shared representations across languages and to identify the processes facilitated in repeated verb generation. In Experiment 1 fluent Spanish-English bilingual speakers exhibited repetition priming both within and between languages, but between-language priming was weaker. In Experiment 2 performance of non-bilingual English and Spanish speakers was equivalent to that of bilingual speakers responding in their dominant language. Experiment 3 used manipulations meant to isolate noun comprehension, verb concept selection, and verb production. The between-language priming in Experiments 1 and 3 indicates that verb concepts are shared across languages and that verb concept selection exhibits facilitation. Experiment 3 showed that the greater within-language priming was due primarily to facilitation of verb production processes.     

Bilingual toddlers’ comprehension of mixed sentences is asymmetrical across their two languages

In bilingual language environments, infants and toddlers listen to two separate languages during the same key years that monolingual children listen to just one and bilinguals rarely learn each of their two languages at the same rate. Learning to understand language requires them to cope with challenges not found in monolingual input, notably the use of two languages within the same utterance (e.g., Do you like the perro? or ¿Te gusta el doggy?). For bilinguals of all ages, switching between two languages can reduce the efficiency in real‐time language processing. But language switching is a dynamic phenomenon in bilingual environments, presenting the young learner with many junctures where comprehension can be derailed or even supported. In this study, we tested 20 Spanish–English bilingual toddlers (18‐ to 30‐months) who varied substantially in language dominance. Toddlers’ eye movements were monitored as they looked at familiar objects and listened to single‐language and mixed‐language sentences in both of their languages. We found asymmetrical switch costs when toddlers were tested in their dominant versus non‐dominant language, and critically, they benefited from hearing nouns produced in their dominant language, independent of switching. While bilingualism does present unique challenges, our results suggest a united picture of early monolingual and bilingual learning. Just like monolinguals, experience shapes bilingual toddlers’ word knowledge, and with more robust representations, toddlers are better able to recognize words in diverse sentences.     

Voluntary language switching in English–Spanish bilingual children

Although bilingual children frequently switch between languages, the psycholinguistic mechanisms underlying the emerging ability to control language choice are unknown. We examined the mechanisms of voluntary language switching in English–Spanish bilingual children during a picture-naming task under two conditions: (1) single-language naming in English and in Spanish; (2) either-language naming, when the children could use whichever language they wanted. The mechanism of inhibitory control was examined by analysing local switching costs and global mixing costs. The mechanism of lexical accessibility was examined by analysing the properties of the items children chose to name in their non-dominant language. The children exhibited significant switching costs across both languages and asymmetrical mixing costs; they also switched into their non-dominant language most frequently on highly accessible items. These findings suggest that both lexical accessibility and inhibition contribute to language choice during voluntary language switching in children.     

Morphological learning in a novel language: A cross-language comparison

Being able to extract and interpret the internal structure of complex word forms such as the English word dance+r+s is crucial for successful language learning. We examined whether the ability to extract morphological information during word learning is affected by the morphological features of one's native tongue. Spanish and Finnish adult participants performed a word–picture associative learning task in an artificial language where the target words included a suffix marking the gender of the corresponding animate object. The short exposure phase was followed by a word recognition task and a generalization task for the suffix. The participants' native tongues vary greatly in terms of morphological structure, leading to two opposing hypotheses. On the one hand, Spanish speakers may be more effective in identifying gender in a novel language because this feature is present in Spanish but not in Finnish. On the other hand, Finnish speakers may have an advantage as the abundance of bound morphemes in their language calls for continuous morphological decomposition. The results support the latter alternative, suggesting that lifelong experience on morphological decomposition provides an advantage in novel morphological learning.     

Acquiring English as a second language via print: The task for deaf children

Only a minority of profoundly deaf children read at age-level. We contend this reflects cognitive and linguistic impediments from lack of exposure to a natural language in early childhood, as well as the inherent difficulty of learning English only through the written modality. Yet some deaf children do acquire English via print. The current paper describes a theoretical model of how children could, in principle, acquire a language via reading and writing. The model describes stages of learning which represent successive, conceptual insights necessary for second/foreign language learning via print. Our model highlights the logical difficulties present when one cannot practice a language outside of reading/writing, such as the necessity of translating to a first language, the need for explicit instruction, and difficulty that many deaf children experience in understanding figurative language. Our model explains why learning to read is often a protracted process for deaf children and why many fail to make progress after some initial success. Because language acquisition is thought to require social interaction, with meaning cued by extralinguistic context, the ability of some deaf individuals to acquire language through print represents an overlooked human achievement worthy of greater attention by cognitive scientists.     

Contrasting contributions of phonological short‐term memory and long‐term knowledge to vocabulary learning in a foreign language

The contributions of phonological short‐term memory and existing foreign vocabulary knowledge to the learning of new words in a second language were compared in a sample of 40 Greek children studying English at school. The children's speed of learning new English words in a paired‐associate learning task was strongly influenced by their current English vocabulary, but was independent of phonological memory skill, indexed by nonword repetition ability. However, phonological memory performance was closely linked to English vocabulary scores. The findings suggest that in learners with considerable familiarity with a second language, foreign vocabulary acquisition is mediated largely by use of existing knowledge representations.