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This study examines the nature of violations in processing one class of binding construction, namely those involving reflexives and their antecedents. When arguments of verbs appear at the point where a syntactic violation is detected, a centroparietal positivity occurs, peaking at 600 ms after the presentation of the stimulus (P600), as is consistent with other types of syntactic anomalies. However, nonarguments in similar sentences fail to elicit the same response. For example, the reflexive in "John's brothers like himself" is in an argument position and elicits the P600 when compared to its grammatical counterpart. The nonargument, participating in the same type of mismatch, "John's brothers like Bill and himself," does not elicit the same positivity. This provides evidence that there are two processes involved in parsing this binding construction, one syntactic and another as yet unidentified, perhaps involving meaning or pragmatics.

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In this paper we add to what is known about the tense-marking limitations of children with specific language impairment (SLI) by exploring the acquisition of regular and irregular past tense, encompassing the age range of 2;6 to 8;9 (years;months) and comparing the performance of 21 children with SLI to that of 23 control children of the same age and 20 younger control children of equivalent mean length of utterance (MLU) at the outset. The analysis differentiated between the morphophonological component of past tense marking and the morphosyntactic component (finiteness). In the morphosyntactic component, the performance of the SLI group trails that of the two control groups over 3.5 years, whereas in the morphophonological component, the SLI group's performance is equivalent to that of the younger controls. Models of growth curves for regular past tense and irregular finiteness marking show the same pattern, with linear and quadratic components and the child's MLU at the outset as the only predictor. For morphophonological growth the picture changes, with an interaction of linear trend and MLU and the child's receptive vocabulary emerging as a predictor. The findings support a morphosyntactic model, such as the extended optional infinitive (EOI) model, with regard to the limitations in finiteness marking and for affected children.

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The studies presented here use an adapted oddball paradigm to show evidence that representations of discrete phonological categories are available to the human auditory cortex. Brain activity was recorded using a 37-channel biomagnetometer while eight subjects listened passively to synthetic speech sounds. In the phonological condition, which contrasted stimuli from an acoustic /dae/-/tae/ continuum, a magnetic mismatch field (MMF) was elicited in a sequence of stimuli in which phonological categories occurred in a many-to-one ratio, but no acoustic many-to-one ratio was present. In order to isolate the contribution of phonological categories to the MMF responses, the acoustic parameter of voice onset time, which distinguished standard and deviant stimuli, was also varied within the standard and deviant categories. No MMF was elicited in the acoustic condition, in which the acoustic distribution of stimuli was identical to the first experiment, but the many-to-one distribution of phonological categories was removed. The design of these studies makes it possible to demonstrate the all-or-nothing property of phonological category membership. This approach contrasts with a number of previous studies of phonetic perception using the mismatch paradigm, which have demonstrated the graded property of enhanced acoustic discrimination at or near phonetic category boundaries.

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This study reports on the outcomes of an investigation designed to evaluate competing accounts of the nature of the grammatical limitations of children with specific language impairment (SLI) with a new comprehension measure involving well-formedness judgments. It is a follow-up to the longitudinal study of Rice, Wexler, and Hershberger (1998), which reported on the production of grammatical morphemes by young children with SLI and 2 control groups of children, one at equivalent levels of mean length of utterance at the outset of the study, the other of equivalent age. In this investigation, we report on grammaticality judgment measures collected from the same 3 groups of children over a period of 2 years for 5 times of measurement. It is the first longitudinal study of grammaticality judgments of children with SLI. The findings show that children's grammatical judgments parallel their productions: Children with SLI can make fine-tuned grammatical judgments to reject morphosyntactic errors they are unlikely to commit, whereas they accept morphosyntactic errors that they are likely to produce. The findings support the extended optional infinitive (EOI) account of morphosyntactic limitation based in underlying grammatical representations and do not support accounts of input processing deficits or production constraints.

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Tense marking in English is relatively late appearing and is especially late for children with Specific Language Impairment (SLI). Little is known about the full course of acquisition for this set of morphemes. Because tense marking is a fundamental property of clause construction, it is central to current theories of morphosyntax and language acquisition. A longitudinal study is reported that encompasses the years of 2;6-8;9 years for typically developing children (N = 43) and 4;6-8;8 years for children with SLI (N = 21). The findings show that a diverse set of morphemes share the property of tense marking; that this set is not mastered until age 4 years in typically developing children and after 7 years for children with SLI; that acquisition shows linear and nonlinear components for both groups, in a typical S-shaped curve; and that nonsyntactic measures are not predictors of growth (including nonverbal intelligence, vocabulary size, and mother's education), whereas initial MLU does predict rate of acquisition. The findings are consistent with a model of Optional Infinitives (OI) for typically developing children (cf. Wexler, 1994, 1996) and Extended Optional Infinitives (EOI) for children with SLI. This model hypothesizes incomplete specification of features of tense that are represented in the grammar.

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Previous family history studies have demonstrated that there are elevated rates of language and language-related impairments in families identified through probands with language impairments. This study examines family histories of children with specific language impairment (SLI) known to have particular grammatical limitations in a core feature of grammatical acquisition, a stage known as Extended Optional Infinitives (EOI). Family affectedness rates are reported for 31 families identified through preschool probands with this clearly defined language impairment and 67 control families, identified through nonaffected preschool children developmentally similar to the probands. It was found that significantly more speech and language difficulties, as well as language-related difficulties, such as reading, were reported for proband families than control families. The elevated rates were obtained for nuclear family members and extended family members as well. Fathers of probands were more often reported as having difficulties (29% for speech/language impairments) than were mothers of probands (7%), but there was no difference between brothers (26%) and sisters (29%). No differences were evident between proband families based on proband gender. The findings are relevant for theoretical models of sources of unexplained variations in grammatical competence in young children. In addition, the findings contribute new information about expected rates of affectedness, means of identification of affected family members, and comorbidity of symptomatology.

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A critical clinical issue is the identification of a clinical marker, a linguistic form or principle that can be shown to be characteristic of children with Specific Language Impairment (SLI). In this paper we evaluate, as candidate clinical markers, a set of morphemes that mark Tense. In English, this includes -s third person singular, -ed regular past, BE, and DO. According to the Extended Optional Infinitive Account (EOI) of Rice, Wexler, and Cleave (1995), this set of morphemes is likely to appear optionally in the grammars of children with SLI at a rate lower than the optionality evident in younger controls. Three groups of preschool children participated: 37 children with SLI, and two control groups, one of 40 MLU-equivalent children and another of 45 age-equivalent children. Three kinds of evidence support the conclusion that a set of morphemes that marks Tense can be considered a clinical marker: (a) low levels of accuracy for the target morphemes for the SLI group relative to either of the two control groups; (b) affectedness for the set of morphemes defined by the linguistic function of Tense, but not for morphemes unrelated to Tense; and (c) a bimodal distribution for Tense-marking morphemes relative to age peers, in which the typical children are at essentially adult levels of the grammar, whereas children in the SLI group were at low (i.e., non-adultlike) levels of performance. The clinical symptoms are evident in omissions of surface forms. Errors of subject-verb agreement and syntactic misuses are rare, showing that, as predicted, children in an EOI stage who are likely to mark Tense optionally at the same time know a great deal about the grammatical properties of finiteness and agreement in the adult grammar. The findings are discussed in terms of alternative accounts of the grammatical limitations of children with SLI and implications for clinical identification.

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The auditory evoked neuromagnetic fields elicited by synthesized speech sounds (consonant-vowel syllables) were recorded in six subjects over the left and right temporal cortices using a 37-channel SQUID-based magnetometer. The latencies and amplitudes of the peaks of the M100 evoked responses were bilaterally symmetric for passively presented stimuli. In contrast, when subjects were asked to discriminate among the same syllabic stimuli, the amplitude of the M100 increased in the left and decreased in the right temporal cortices. Single equivalent current dipole modeling of the activity elicited by all stimulus-types localized to a well-circumscribed area in supratemporal auditory cortex. The results suggest that attentional modulation affects the two supratemporal cortices in a differential manner. Task-conditioned attention to speech sounds is reflected in lateralized supratemporal cortical responses possibly concordant with hemispheric language dominance.

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English-speaking children with specific language impairment (SLI) are known to have particular difficulty with the acquisition of grammatical morphemes that carry tense and agreement features, such as the past tense -ed and third-person singular present -s. In this study, an Extended Optional Infinitive (EOI) account of SLI is evaluated. In this account, -ed, -s, BE, and DO are regarded as finiteness markers. This model predicts that finiteness markers are omitted for an extended period of time for nonimpaired children, and that this period will be extended for a longer time in children with SLI. At the same time, it predicts that if finiteness markers are present, they will be used correctly. These predictions are tested in this study. Subjects were 18 5-year-old children with SLI with expressive and receptive language deficits and two comparison groups of children developing language normally: 22 CA-equivalent (5N) and 20 younger, MLU-equivalent children (3N). It was found that the children with SLI used nonfinite forms of lexical verbs, or omitted BE and DO, more frequently than children in the 5N and 3N groups. At the same time, like the normally developing children, when the children with SLI marked finiteness, they did so appropriately. Most strikingly, the SLI group was highly accurate in marking agreement on BE and DO forms. The findings are discussed in terms of the predictions of the EOI model, in comparison to other models of the grammatical limitations of children with SLI.

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Language is species-specific, species-wide, and highly structured. Its principles (Universal Grammar) are innate (genetically determined) in the child, although some linguistic capacity is subject to a maturational schedule, examples of which are given. Some particular aspects of language are learned, in a way driven by Universal Grammar. However, empiricist "learning theories" of all types are far too weak to be useful in explaining either the final adult language or the precise timing of developmental processes. The assumption of Universal Grammar is, in fact, crucial in explaining what kind of learning actually takes place.

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The allele frequency distribution of two highly polymorphic DNA sequences has been determined in three ethnic groups (American blacks, Caucasoids, and Hispanics) from the New York metropolitan area. The two loci examined were D14S1 and the flanking region of HRAS-1. The former was analyzed in EcoRI-digested DNA and the latter in TaqI-digested DNA. Approximately 700 DNA samples from unrelated individuals were digested with each of these enzymes and hybridized with the appropriate recombinant DNA probes. The size range of the DNA fragments detected for the D14S1 polymorphism varied from 14.3 to 32.5 kilobase pairs (kbp). The number of alleles identified under the experimental conditions used in this study was more than 40. For the HRAS-1 polymorphism, we have detected 18 different alleles varying in size from 1.85 to 4.5 kbp. Although the number of alleles observed in the different ethnic groups examined was very similar, the relative frequency of them varied significantly. The results presented here can be used as the basis for the utilization of DNA RFLP for the purpose of identity, such as paternity determinations or the analysis of forensic material. As an example, we have compared the results of paternity cases analyzed by HLA typing with those obtained with these two DNA polymorphisms. The values of paternity index and power of exclusion were similar by both procedures.

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Disfluency characteristics of 36 nonstuttering boys aged 2, 4, and 6 were analyzed from tape-recorded speech samples made during free play within neutral and stress situations. Comparisons of frequency of disfluency were made among the different ages within each situation. In the neutral situation, 2-year-olds had significantly higher disfluency frequencies than either 4- or 6-year-olds for word repetitions and phrase repetitions; 2-year-olds also had a higher frequency of disrhythmic phonations than 6-year-olds but not than 4-year-olds. In the stress situation, 2-year-olds had a higher frequency of average oscillation (number of repetitions per instance of disfluency) than either 4- or 6-year-olds and a higher frequency of disrhythmic phonations than 6-year-olds. Comparisons of frequency of disfluency were also made between the neutral and stress situations. The only statistically significant differences were for word repetitions and phrase repetitions for 2-year-olds, with higher means for the neutral situation.

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This paper reports 42 severely-to-profoundly deaf subjects, 6 of whom have better hearing in the range of 8 to 14 kHz than below 8 kHz. Data on speech capabilities in these six subjects suggest that this ultra-audiometric range may contribute to their speech comprehension and control.

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