Tapping into the interplay of lexical and number knowledge using fast mapping: A longitudinal eye-tracking study with two-year-olds.

Language skills and mathematical competencies are argued to influence each other during development. While a relation between the development of vocabulary size and mathematical skills is already documented in the literature, this study further examines how children's ability to map a novel word to an unknown object as well as their ability to retain this word from memory may be related to their knowledge of number words. Twenty-five children were tested longitudinally (at 30 and at 36 months of age) using an eye-tracking-based fast mapping task, the Give-a-Number task, and standardized measures of vocabulary. The results reveal that children's ability to create and retain a mental representation of a novel word was related to number knowledge at 30 months, but not at 36 months while vocabulary size correlated with number knowledge only at 36 months. These results show that even specific mapping processes are initially related to the acquisition of number words and they speak for a parallelism between the development of lexical and number-concept knowledge despite their semantic and syntactic differences.

Number Dissimilarity Effects in Object-Initial Sentence Comprehension by German-Speaking Children With Specific Language Impairment.

Purpose This study examines the contribution of number morphology to language comprehension abilities among children with specific language impairment (SLI) and age-matched controls. It addresses the question of whether number agreement facilitates the comprehension accuracy of object-initial declarative sentences. According to the predictions of the structural intervention account for German, number agreement should assist the correct interpretation of object-initial sentences. Method This study examines German-speaking children with SLI and a control group of age-matched typically developing children on their sentence comprehension skills for auditory presented subject-verb-object and object-verb-subject (OVS) sentences. The sentences were manipulated with respect to the number properties of the noun phrases (e.g., one plural and one singular, or both singular) and the number agreement of the verb. Results The group of children with SLI demonstrated poorer comprehension accuracy in comparison to controls. Comprehension difficulty was limited to OVS sentences among children with SLI. In addition, children with SLI comprehended OVS sentences in which number agreement (with plural subject and verb inflection) indicated the noncanonical word order more accurately than OVS sentences with two singular noun phrases and therein did not differ from controls. Conclusion The study suggests that number agreement helps alleviate the difficulty with OVS sentences and enhances comprehension accuracy, despite the finding that children with SLI exhibit lower comprehension accuracy and more heterogeneous interindividual differences, relative to controls. Supplemental Material https://doi.org/10.23641/asha.13718029.

Reading as a Predictor of Complex Syntax. The Case of Relative Clauses.

BACKGROUND: The current study aims at better characterizing the role of reading skills as a predictor of comprehension of relative clauses. Well-established cross-linguistic evidence shows that children are more accurate in the comprehension of subject-extracted relative clauses in comparison to the object-extracted counterpart. Children with reading difficulties are known to perform less accurately on object relatives at the group level compared to typically developing children. Given that children's performance on reading tasks is shown to shape as a continuum, in the current study we attempted to use reading skills as a continuous variable to predict performance on relative clauses. METHODS: We examined the comprehension of relative clauses in a group of 30 English children (7-11 years) with varying levels of reading skills. Reading skills varied on a large spectrum, from poor readers to very skilled readers, as assessed by the YARC standardized test. The experimental task consisted of a picture-matching task. Children were presented with subject and object relative clauses and they were asked to choose one picture - out of four - that would best represent the sentence they heard. At the same time, we manipulated whether the subject and object nouns were either matching (both singular or both plural) or mismatching (one singular, the other plural) in number. RESULTS: Our analysis of accuracy shows that subject relatives were comprehended more accurately overall than object relatives, that responses to sentences with noun phrases mismatching in number were more accurate overall than the ones with matching noun phrases and that performance improved as a function of reading skills. Within the match subset, while the difference in accuracy between subject and object relatives is large in poor readers, the difference is reduced with better reading skills, almost disappearing in very skilled readers. DISCUSSION: Beside replicating the well-established findings on the subject-object asymmetry, number facilitation in the comprehension of relative clauses, and a better overall performance by skilled readers, these results indicate that strong reading skills may determine a reduction of the processing difficulty associated with the hardest object relative clause condition (i.e., match), causing a reduction of the subject-object asymmetry.

Testing the effect of an arbitrary subject pronoun on relative clause comprehension: a study with Hebrew-speaking children.

Previous studies have found that Hebrew-speaking children accurately comprehend object relatives (OR) with an embedded non-referential arbitrary subject pronoun (ASP). The facilitation of ORs with embedded pronouns is expected both from a discourse-pragmatics perspective and within a syntax-based locality approach. However, the specific effect of ASP might also be driven by a mismatch in grammatical features between the head noun and the pronoun, or by its relatively undemanding referential properties. We tested these possibilities by comparing ORs whose embedded subject is either ASP, a referential pronoun, or a lexical noun phrase. In all conditions, grammatical features were controlled. In a referent-identification task, the matching features made ORs with embedded pronouns difficult for five-year-olds. Accuracy was particularly low when the embedded pronoun was referential. These results indicate that embedded pronouns do not facilitate ORs across the board, and that the referential properties of pronouns affect OR processing.

The Peaceful Co-existence of Input Frequency and Structural Intervention Effects on the Comprehension of Complex Sentences in German-Speaking Children.

The predictions of two contrasting approaches to the acquisition of transitive relative clauses were tested within the same groups of German-speaking participants aged from 3 to 5 years old. The input frequency approach predicts that object relative clauses with inanimate heads (e.g., the pullover that the man is scratching) are comprehended earlier and more accurately than those with an animate head (e.g., the man that the boy is scratching). In contrast, the structural intervention approach predicts that object relative clauses with two full NP arguments mismatching in number (e.g., the man that the boys are scratching) are comprehended earlier and more accurately than those with number-matching NPs (e.g., the man that the boy is scratching). These approaches were tested in two steps. First, we ran a corpus analysis to ensure that object relative clauses with number-mismatching NPs are not more frequent than object relative clauses with number-matching NPs in child directed speech. Next, the comprehension of these structures was tested experimentally in 3-, 4-, and 5-year-olds respectively by means of a color naming task. By comparing the predictions of the two approaches within the same participant groups, we were able to uncover that the effects predicted by the input frequency and by the structural intervention approaches co-exist and that they both influence the performance of children on transitive relative clauses, but in a manner that is modulated by age. These results reveal a sensitivity to animacy mismatch already being demonstrated by 3-year-olds and show that animacy is initially deployed more reliably than number to interpret relative clauses correctly. In all age groups, the animacy mismatch appears to explain the performance of children, thus, showing that the comprehension of frequent object relative clauses is enhanced compared to the other conditions. Starting with 4-year-olds but especially in 5-year-olds, the number mismatch supported comprehension-a facilitation that is unlikely to be driven by input frequency. Once children fine-tune their sensitivity to verb agreement information around the age of four, they are also able to deploy number marking to overcome the intervention effects. This study highlights the importance of testing experimentally contrasting theoretical approaches in order to characterize the multifaceted, developmental nature of language acquisition.

Discourse accessibility constraints in children's processing of object relative clauses.

Children's poor performance on object relative clauses has been explained in terms of intervention locality. This approach predicts that object relatives with a full DP head and an embedded pronominal subject are easier than object relatives in which both the head noun and the embedded subject are full DPs. This prediction is shared by other accounts formulated to explain processing mechanisms. We conducted a visual-world study designed to test the off-line comprehension and on-line processing of object relatives in German-speaking 5-year-olds. Children were tested on three types of object relatives, all having a full DP head noun and differing with respect to the type of nominal phrase that appeared in the embedded subject position: another full DP, a 1st- or a 3rd-person pronoun. Grammatical skills and memory capacity were also assessed in order to see whether and how they affect children's performance. Most accurately processed were object relatives with 1st-person pronoun, independently of children's language and memory skills. Performance on object relatives with two full DPs was overall more accurate than on object relatives with 3rd-person pronoun. In the former condition, children with stronger grammatical skills accurately processed the structure and their memory abilities determined how fast they were; in the latter condition, children only processed accurately the structure if they were strong both in their grammatical skills and in their memory capacity. The results are discussed in the light of accounts that predict different pronoun effects like the ones we find, which depend on the referential properties of the pronouns. We then discuss which role language and memory abilities might have in processing object relatives with various embedded nominal phrases.

Number dissimilarities facilitate the comprehension of relative clauses in children with (Grammatical) Specific Language Impairment.

This study investigates whether number dissimilarities on subject and object DPs facilitate the comprehension of subject- and object-extracted centre-embedded relative clauses in children with Grammatical Specific Language Impairment (G-SLI). We compared the performance of a group of English-speaking children with G-SLI (mean age: 12;11) with that of two groups of younger typically developing (TD) children, matched on grammar and receptive vocabulary, respectively. All groups were more accurate on subject-extracted relative clauses than object-extracted ones and, crucially, they all showed greater accuracy for sentences with dissimilar number features (i.e., one singular, one plural) on the head noun and the embedded DP. These findings are interpreted in the light of current psycholinguistic models of sentence comprehension in TD children and provide further insight into the linguistic nature of G-SLI.

Rethinking the acquisition of relative clauses in Italian: towards a grammatically based account.

In a number of studies, the acquisition of restrictive relative clauses (RCs) shows contrasting findings regarding comprehension and production, with the former usually delayed up to the age of five. As previously claimed in the literature, we suggest that this delay is a task artifact and we present a new procedure for the assessment of restrictive RCs. Data from three- to seven-year-old Italian children were collected and results show that children understand object RCs with preverbal subject in an adult-like manner at four years of age, but some of the three-year-old children were already above chance. Subject relatives show at ceiling performance from three years of age. We consider our results as evidence of continuity between early and adult competence grammars. Children's non-target responses are interpreted as grammatical options exploited by an immature performance system.

Grammatical feature dissimilarities make relative clauses easier: A comprehension study with Italian children.

The Relativized Minimality approach to A'-dependencies (Friedmann et al., 2009) predicts that headed object relative clauses (RCs) and which-questions are the most difficult, due to the presence of a lexical restriction on both the subject and the object DP which creates intervention. We investigated comprehension of center-embedded headed object RCs with Italian children, where Number and Gender feature values on subject and object DPs are manipulated. We found that, Number conditions are always more accurate than Gender ones, showing that intervention is sensitive to DP-internal structure. We propose a finer definition of the lexical restriction where external and syntactically active features (such as Number) reduce intervention whereas internal and (possibly) lexicalized features (such as Gender) do so to a lesser extent. Our results are also compatible with a memory interference approach in which the human parser is sensitive to highly specific properties of the linguistic input, such as the cue-based model (Van Dyke, 2007).