Stephen Crain

Language acquisition in the absence of experience

A fundamental goal of linguistic theory is to explain how natural languages are acquired. This paper describes some recent findings on how learners acquire syntactic knowledge for which there is little, if any, decisive evidence from the environment. The first section presents several general observations about language acquisition that linguistic theory has tried to explain and discusses the thesis that certain linguistic properties are innate because they appear universally and in the absence of corresponding experience. A third diagnostic for innateness, early emergence, is the focus of the second section of the paper, in which linguistic theory is tested against recent experimental evidence on childrens acquisition of syntax.

Language mechanisms and reading disorder: A modular approach

Abstract In this paper we consider a complex of language-related problems that research has identified in children with reading disorder and we attempt to understand this complex in relation to proposals about the language processing mechanism. The perspective gained by considering reading problems from the standpoint of language structure and language acquisition allows us to pose specific hypotheses about the causes of reading disorder. The hypotheses are then examined from the standpoint of an analysis of the demands of the reading task and a consideration of the state of the unsuccessful reader in meeting these demands. The remainder of the paper pursues one proposal about the source of reading problems, in which the working memory system plays a central part. This proposal is evaluated in the light of empirical research which has attempted to tease apart structural knowledge and memory capacity both in normal children and in children with notable reading deficiencies.

Why children and adults sometimes (but not always) compute implicatures

Noveck (2001) argued that children even as old as 11 do not reliably endorse a scalar interpretation of weak scalar terms (some, might, or) (cf. Braine & Rumain, 1981; Smith, 1980). More recent studies suggest, however, that childrens apparent failures may depend on the experimental demands (Papafragou & Musolino, 2003). Although previous studies involved children of different ages as well as different tasks, and are thus not directly comparable, nevertheless a common finding is that children do not seem to derive scalar implicatures to the same extent as adults do. The present article describes a series of experiments that were conducted with Italian speaking subjects (children and adults), focusing mainly on the scalar term some. Our goal was to carefully examine the specific conditions that allow the computation of implicatures by children. In so doing, we demonstrate that children as young as 7 (the youngest age of the children who participated in the Noveck study) are able to compute implicatures in experimental conditions that properly satisfy certain contextual prerequisites for deriving such implicatures. We also present further results that have general consequences for the research methodology employed in this area of study. Our research indicates that certain tasks mask childrens understanding of scalar terms, not only including the task used by Noveck, but also tasks that employ certain explicit instructions, such as the training task used by Papafragou & Musolino (2003). Our findings indicate further that, although explicit training apparently improves childrens ability to draw implicatures, children nevertheless fail to achieve adult levels of performance for most scalar terms even in such tasks, and that the effects of instruction do not last beyond the training session itself for most children. Another relevant finding of the present study is that some of the manipulations of the experimental context have an effect on all subjects, whereas others produce effects on just a subset of children. Individual differences of this kind may have been concealed in previous research because performance by individual subjects was not reported. Our general conclusions are that even young children (7-year olds) have the prerequisites for deriving scalar implicatures, although these abilities are revealed only when the conversational background is natural.

Nature, Nurture and Universal Grammar

In just a few years, children achieve a stable state of linguistic competence, making them effectively adults with respect to: understanding novel sentences, discerning relations of paraphrase and entailment, acceptability judgments, etc. One familiar account of the language acquisition process treats it as an induction problem of the sort that arises in any domain where the knowledge achieved is logically underdetermined by experience. This view highlights the ‘cues’ that are available in the input to children, as well as childrens skills in extracting relevant information and forming generalizations on the basis of the data they receive. Nativists, on the other hand, contend that language-learners project beyond their experience in ways that the input does not even suggest. Instead of viewing language acqusition as a special case of theory induction, nativists posit a Universal Grammar, with innately specified linguistic principles of grammar formation. The ‘nature versus nurture’ debate continues, as various “poverty of stimulus” arguments are challenged or supported by developments in linguistic theory and by findings from psycholinguistic investigations of child language. In light of some recent challenges to nativism, we rehearse old poverty-of stimulus arguments, and supplement them by drawing on more recent work in linguistic theory and studies of child language.

Navigating negative quantificational space

Abstract This paper reports the findings from an interconnected set of experiments designed to assess childrens knowledge of the semantic interactions between negation and quantified NPs. Our main finding is that young children, unlike adults, systematically interpret these elements on the basis of their position in overt syntax. We argue that this observation can be derived from an interplay between fundamental properties of universal grammar and basic learning principles. We show that even when childrens semantic knowledge appears to differ from that of adults, the observed differences occur within well-defined boundaries, that is, within the limits imposed by the theory of universal grammar. Moreover, we point to the (positive) evidence needed by children in their passage to adulthood. We conclude that children have incomplete rather than inaccurate knowledge, in accordance with the continuity hypothesis. Together, these observations support the conclusion that children draw from an arsenal of innately specified principles in the acquisition of the grammar of quantification.

Reception of language in broca's aphasia

Abstract This experiment tests between two competing hypotheses about the source of failures in comprehension by Broca-type aphasics with agrammatic production. These are characterised as (1) the hypothesis that these aphasic individuals have sustained a partial loss in syntactic knowledge, and (2) the hypothesis that, despite intact structural knowledge, they suffer from an inability to put that knowledge to use in comprehension tasks such as object manipulation and sentence-picture matching. To decide between the hypotheses, this study compared the speed and accuracy of Broca-type aphasics with a control group of normal subjects using an on-line grammaticality judgement task in which the anomaly involved closed-class vocabulary items. The results are in accord with the view that the source of agrammatic performance is not a loss of syntactic knowledge, as the responses of the aphasic group closely mirror those of the control group (e.g. word position effects were found for both groups). The results are ...

Acquisition of cognitive compiling

Abstract Language involves both structure and process. Giving each its due, we present a cognitive process model and show how its empirical success is related to claims about syntactic structure. Innate constraints on syntax are a central issue in linguistic theory, so it is a matter of concern that a widely accepted view of phrase structure constraints (X-bar theory) appears to be violated in some recent comprehension experiments with children. However, what is directly observed in the experiments is not a syntactic structure but the execution of a plan. We present a language of process for representing such plans and thereby provide a unified explanation of several developmental phenomena, including the results of the above experiments and of new experiments suggested by our approach. The explanation is in terms of the cognitive resources required to formulate and execute a plan. Since the explanation is based on nonsyntactic processing, the childrens syntax need no longer be held faulty. This conclusion invigorates the claim that the range of phrase structures available to children is biologically constrained.

Anomaly Detection: Eye Movement Patterns

The symptom of a garden path in sentence processing is an apparent anomaly in the input string. This anomaly signals to the parser that an error has occurred, and provides cues for how to repair it. Anomaly detection is thus an important aspect of sentence processing. In the present study, we investigated how the parser responds to unambiguous sentences that contain syntactic anomalies and pragmatic anomalies, examining records of eye movement during reading. While sensitivity to the two kinds of anomaly was very rapid and essentially simultaneous, qualitative differences existed in the patterns of first-pass reading times and eye regressions. The results are compatible with the proposal that syntactic information and pragmatic information are used differently in garden-path recovery.

On the acquisition of pronominal reference: Review of: L. Solan, Pronominal reference: Child language and the theory of grammar

Abstract Lawrence Solans Pronominal Reference is one of the most detailed attempts to relate language acquisition research to current linguistic theory. Solan focuses on the structural relationship between pronouns and their antecedents. A theory of markedness is introduced in which portions of the statement of the restriction prohibiting backward anaphora represent stages of acquisition. Solan presents a series of experiments designed to demonstrate how this staged acquisition process is constrained by innate principles of Universal Grammar. Our review has three parts. First we discuss Solans theoretical contributions to the study of anaphora. Then we outline his six experiments with 5- to 8-year old children. Finally, we discuss Solans conclusions and, in some cases, offer alternatives of our own.

Measurement of brain function in pre-school children using a custom sized whole-head MEG sensor array

OBJECTIVE Conventional whole-head MEG systems have fixed sensor arrays designed to accommodate most adult heads. However arrays optimised for adult brain measurements are suboptimal for research with the significantly smaller heads of young children. We wished to measure brain activity in children using a novel whole-head MEG system custom sized to fit the heads of pre-school-aged children. METHODS Auditory evoked fields were measured from seven 4-year-old children in a 64-channel KIT whole-head gradiometer MEG system. RESULTS The fit of heads in the MEG helmet dewars, defined as the mean of sensor-to-head centre distances, were substantially better for children in the child helmet dewar than in the adult helmet dewar, and were similar to head fits obtained for adults in a conventional adult MEG system. Auditory evoked fields were successfully measured from all seven children and dipole source locations were computed. CONCLUSIONS These results demonstrate the feasibility of routinely measuring neuromagnetic brain function in healthy, awake pre-school-aged children. SIGNIFICANCE The advent of child-sized whole-head MEG systems opens new opportunities for the study of cognitive brain development in young children.