Verb inflection and verb diversity in three populations: agrammatic speakers, normally developing children, and children with specific language impairment (SLI)

The present study focuses on the relation between a grammatical and a lexical-semantic aspect of verb production. The spontaneous speech of three different populations (normally developing children, agrammatic aphasics, and children with a specific language impairment) has been analyzed with respect to the proportion of finite clauses and the diversity of the produced lexical verbs. The group results show that in the three populations both the proportion of finite verbs and the variability of the lexical verbs is low. When the individual scores are considered, differences between the normally developing children and the language-impaired subjects show up. Whereas in normally developing children verb finiteness and verb variability go hand-in-hand, the reverse relationship between these variables is observed in the agrammatic aphasics and the children with a specific language impairment. Given this reverse relationship, it is probable to assume two separate disorders. We therefore suggest an impairment at the interface level where lexical information and syntactic structure are integrated during sentence production.     

Frequency of verb use in young children who stutter

Several recent studies have suggested that young children who stutter (CWS) tend to show depressed lexical performance relative to peers. Given the developmental literature as well as several studies of verb processing in individuals who stutter, verbs may pose a particular challenge for this group. The purpose of the present study was to examine verb use in CWS. In theory, if young CWS differ in their production of verbs, this finding would partially explain the findings of studies that probed conversational vocabulary skills more generally. Fifteen CWS and 15 children who do not stutter (CWNS) participated in a play-based conversational sample with a parent. Samples were analyzed for the total number of verbs, the number of different verbs, and the proportion of general all-purpose (GAP) verbs within the samples. CWS produced significantly fewer different verbs and total verbs than the CWNS. However, previously reported near-significant differences in utterance length between groups would appear to temper the robustness of this finding. The groups did not differ in the proportion of GAP verbs used, suggesting that the CWS did not over-rely on GAP verbs in conversational language production but rather used these verbs to the same extent as their peers. Educational objectives: As a result of this activity, the participant will be able to: (1) relate the purpose and rationale for examining verb use in children who stutter (CWS); (2) summarize the procedures used to assess verb use and GAP verb use in the present study; (3) explain the findings of the present study; (4) relate findings to the extant literature on lexical diversity in CWS.     

Production of lexical categories in French children with SLI and in normally developing children matched for MLU

Free speech recording samples of two groups of French SLI children aged 48 and 62 months (matched for MLU, 1.70) and two groups of French normally developing children aged 26 and 36 month (matched for MLU, 3.2) were compared to determine whether they showed a difference in the use of lexical categories. A category-by-category comparison showed few significant differences. For low MLU children, SLI produced significantly fewer infinitives, past participles, copulas, and demonstrative pronouns. For high MLU children, the difference persisted only in past participles use. As for English SLI children, French SLI children were delayed in their acquisition of verbs. However, the differences in the syntactic structure of English and French ruled out a syntactic explanation of the deficit. Phonetic problems seem to decrease with age, so they cannot be the only explanation behind the difficulties of SLI children, which probably involve cognitive problems such as processing limitations.     

Patterns of comprehension and production of nouns and verbs in agrammatism: implications for lexical organization

This study examined the relationship between verb retrieval and verb-argument-structure properties in seven agrammatic aphasic patients using tasks requiring access to the verb's lexicon for both comprehension- and productionlike processes. Results showed intact comprehension of both nouns and verbs and noun naming, but impaired naming of verbs. Subjects also demonstrated near-normal performance on a grammaticality judgment task involving verb-argument-structure violations but were impaired in categorizing verbs by type (based on number of obligatory arguments). In both naming and categorization conditions, a hierarchy of verb difficulty emerged. Subjects were more accurate in naming/categorizing one-place verbs than two-place verbs and more accurate in naming/categorizing two-place verbs than three-place verbs. The pattern of selective impairment in lexical access/retrieval supports the hypothesis that one dimension of normal lexical organization is by form class. The results also suggest that no necessary relationship exists between production difficulties and comprehension of nouns/verbs in agrammatism. Further, the performance pattern noted supports the claim that verb-argument-structure properties, an important component of the verb lexicon, influence verb production at the single-word and at the sentence level. Subjects' performance on different tasks suggests that the locus of breakdown in the verb-retrieval processes for productionlike tasks may be in accessing information at the lemma level of representation as per Bock's model (1995) of sentence production.     

Lexical decision in sentences: Effects of syntactic structure

A lexical decision paradigm was used to examine syntactic influence on word recognition in sentences. Initial fragments of sentences were presented visually (CRT display) one word at a time (at reading speeds), from left to right. The string terminated with the appearance of a lexical decision target. The grammatical structure of the incomplete sentence affected lexical decision reaction time (RT). In Experiment 1, modal verb contexts followed by main verb targets and preposition contexts followed by noun targets produced lower RTs than did the opposite pairings (i.e., modal/noun and preposition/verb). In Experiment 2, transitive verb contexts followed by noun targets and subject noun phrase contexts followed by verb targets yielded lower RTs than did the opposite pairings. Similar contrasts for adjective targets did not yield comparable effects in Experiment 2, but did when the adjective was the head of a predictable phrase (Experiment 4). In Experiment 3, noun targets yielded lower RTs than did verb targets after contexts of a transitive verb followed by a prepositional phrase. An account of these effects is offered in terms of parsing constraints on phrasal categories.     

Lexical, morphological, and syntactic aspects of verb production in agrammatic aphasics

Agrammatic aphasics do not exhibit a normal pattern of verb production; their spontaneous speech is said to lack verbs, and the verbs that are produced lack inflection. The current article focuses on the lexical, morphological, and syntactic aspects of verbs in spontaneous speech of a group of Dutch agrammatic speakers. Dutch is a so-called verb-second language in which the finite verb in the matrix clause is in the second position and nonfinite verbs are in the final position. The analysis shows that agrammatic speakers are sensitive to this relation; they virtually never produce finite verbs in the final clause position or nonfinite verbs in the second position. Nevertheless, they produce significantly fewer finite clauses than do non-brain-damaged speakers. The diversity of the lexical verbs in spontaneous speech is also lower than in non-brain-damaged speakers, but this is due to less variation in the finite lexical verbs. Hence, it is suggested that the problems with verbs in Dutch agrammatic spontaneous speech are restricted to finite lexical verbs. In an experiment, it was evaluated whether these problems with finite lexical verbs are caused by a morphological deficit or a syntactic deficit. The data show that a syntactic deficit is more likely; Dutch agrammatic speakers produce finite verbs in the base-generated position (i.e., in the embedded clause) significantly better than finite verbs that have been moved to the second position (i.e., in the matrix clause). From these data, the authors conclude that in Dutch, a verb-second language, agrammatic aphasics demonstrate specific problems with moved finite verbs, although they are perfectly aware of the relation between verb position and verb finiteness. This syntactic problem affects not only the proportion of finite verbs but also the diversity of the verbs and, hence, communicative contents.     

Category norm data and relationships with lexical frequency and typicality within verb semantic categories

The aim of the present study was to expand the scope of category norm and typicality data to include verbs for use when investigating semantic memory in fields such as linguistics, psychology, and aphasiology. Two experiments were conducted. In the first, participants were asked to list verbs within 10 semantic categories (e.g. breaking, cleaning, cooking, etc.) and 10 noun categories (e.g. animals, fruit, tools, etc.). In the second experiment, participants were asked to rate the typicality of verbs within 8 of the previously investigated verb categories. Although participants listed fewer verbs in verb categories than nouns in noun categories, the overall patterns with regard to correlation analyses between production frequency, mean rank of responses, lexical frequency, and typicality were consistent with those observed in noun categories. These patterns are also consistent with those observed in previous research. Potential similarities and differences between nouns and verbs, as well as future applications of such data, are discussed.     

A cross-linguistic study of early lexical development

Cross-linguistic studies have shown that children can vary markedly in rate, style, and sequence of grammatical development, within and across natural languages. It is less clear whether there are robust cross-linguistic differences in early lexical development, with particular reference to the onset and rate of growth in major lexical categories (e.g., nouns, verbs, adjectives and grammatical function words). In this study, we present parental report data on the first stages of expressive and receptive lexical development for 659 English infants and 195 Italian infants between 8 and 16 months of age. Although there are powerful structural differences between English and Italian that could affect the order in which nouns and verbs are acquired, no differences were observed between these languages in the emergence and growth of lexical categories. In both languages, children begin with words that are difficult to classify in adult part-of-speech categories (i.e., “routines”). This is followed by a period of sustained growth in the proportion of vocabulary contributed by common nouns. Verbs, adjectives, and grammatical function words are extremely rare until children have vocabularies of at least 100 words. The same sequences are observed in production and comprehension, although verbs are reported earlier for receptive vocabulary. Our results are compared with other reports in the literature, with special reference to recent claims regarding the early emergence of verbs in Korean.     

The role of configurational asymmetry in the lexical access of prefixed verbs: evidence from French

In this paper we investigated the effects of configurational asymmetry in prefixed verbs in French. We used a simple lexical decision paradigm to compare prefixed verbs with external and internal prefixes as specified in linguistic theory (Di Sciullo, 1997) where external prefixes do not change the aktionsart and the verb argument structure of the verb, but internal prefixes do change the aktionsart and may change the verb argument structure of the verb. In Experiment 1 we tested the bi-valent prefix dé- where the configurational difference between external and internal properties of a prefix did not elicit differential response latencies. However, in Experiment 2, where unambiguous prefixes (internal en- and external ré-) were tested, the external prefix elicited longer latencies. These results are discussed with respect to the linguistic constraints the configurational properties of prefixes place upon psycholinguistic models of lexical access, as well as with respect to the effects of prefix bi-valence in the recognition of prefixed verbs.     

Action naming in anomic aphasic speakers: effects of instrumentality and name relation

Many studies reveal effects of verb type on verb retrieval, mainly in agrammatic aphasic speakers. In the current study, two factors that might play a role in action naming in anomic aphasic speakers were considered: the conceptual factor instrumentality and the lexical factor name relation to a noun. Instrumental verbs were shown to be better preserved than non-instrumental verbs in a group of anomic aphasic speakers but not in a group of Broca's aphasic speakers. Name relation to a noun improved the performance of the anomic aphasic speakers as well. Again, no effect was found in the group of Broca's aphasic speakers. Verbs with a name relation to a noun were better retrieved in action naming than verbs without a name relation. These findings are discussed in terms of the spreading activation theory of Dell. (Dell, G. S. (1986). A spreading activation theory of retrieval in sentence production. Psychological Review 93, 283-321.).     

An Elicited‐Production Study of Inflectional Verb Morphology in Child Finnish

Many generativist accounts (e.g., Wexler, 1998) argue for very early knowledge of inflection on the basis of very low rates of person/number marking errors in young children's speech. However, studies of Spanish (Aguado‐Orea & Pine, 2015) and Brazilian Portuguese (Rubino & Pine, 1998) have revealed that these low overall error rates actually hide important differences across the verb paradigm. The present study investigated children's production of person/number marked verbs by eliciting present tense verb forms from 82 native Finnish‐speaking children aged 2;2–4;8 years. Four main findings were observed: (a) Rates of person/number marking errors were higher in low‐frequency person/number contexts, even excluding children who showed no evidence of having learned the relevant morpheme, (b) most errors involved the use of higher frequency forms in lower frequency person/number contexts, (c) error rates were predicted not only by the frequency of person/number contexts (e.g., 3sg > 2pl) but also by the frequency of individual “ready‐inflected” lexical target forms, and (d) for low‐frequency verbs, lower error rates were observed for verbs with high phonological neighborhood density. It is concluded that any successful account of the development of verb inflection will need to incorporate both (a) rote‐storage and retrieval of individual inflected forms and (b) phonological analogy across them.     

The influence of age of acquisition,root frequency,and context availability in processing nouns and verbs

In the Italian language there is a higher number of inflectional suffixes in verbs than in nouns, and this might imply that verbs are more likely to undergo a morphological analysis in terms of root and suffix as compared to nouns (Traficante & Burani, unpublished observations). Moreover, verbs tend to be more abstract than nouns, and this aspect might make verb processing more difficult. Finally, the developmental gap in the production of nouns and verbs suggests that age of acquisition might affect noun and verbs differently. Nouns and verbs were presented in a lexical decision and in a naming task. The morphological variable root frequency in addition to word frequency, length and word age of acquisition, and the semantic variables concreteness and context availability (Schwanenflugel, Harnishfeger, & Stowe, 1988) were used as predictors in multiple-regression analyses in which lexical decision and naming latencies were the dependent variables. The results showed that age of acquisition, context availability, and root frequency are all important in predicting both lexical decision and naming latencies for nouns and verbs, but age of acquisition and root frequency are better predictors of the differences in processing Italian nouns and verbs.     

Evaluation of narrative abilities in patients suffering from Duchenne Muscular Dystrophy

The present work investigated cognitive, linguistic and narrative abilities in a group of children suffering from Duchenne Muscular Dystrophy, an allelic X-linked recessive disorder caused by mutations in the gene encoding dystrophin. The patients showed mildly reduced IQ with lower Verbal than Performance Intelligence Quotient and were mildly affected in visual attention and short-term memory processing. At the linguistic assessment, neither receptive (word comprehension) nor expressive (naming tasks and fluency) lexical abilities were impaired. However, their narratives were qualitatively inferior with respect to those produced by a group of typically developing children. Their speech samples were characterized by the presence of fewer verbs and complete sentences. It is suggested that the reduced production of complete sentences is due to a selective problem in verb argument structure generation. Since the lack of dystrophin is assumed to produce effects on the maturation of the cerebellum, whose involvement has been recently suggested in verb and syntactic processing, these findings may lend indirect support to the hypothesis of a cerebellar-cortical circuit specialized in verb and sentence production.     

Psycholinguistic measures for German verb pairs: Semantic transparency,semantic relatedness,verb family size,and age of reading acquisition

A central issue in visual and spoken word recognition is the lexical representation of complex words—in particular, whether the lexical representation of complex words depends on semantic transparency: Is a complex verb like understand lexically represented as a whole word or via its base stand, given that its meaning is not transparent from the meanings of its parts? To study this issue, a number of stimulus characteristics are of interest that are not yet available in public databases of German. This article provides semantic association ratings, lexical paraphrases, and vector-based similarity measures for German verbs, measuring (a) the semantic transparency between 1,259 complex verbs and their bases, (b) the semantic relatedness between 1,109 verb pairs with 432 different bases, and (c) the vector-based similarity measures of 846 verb pairs. Additionally, we include the verb regularity of all verbs and two counts of verb family size for 184 base verbs, as well as estimates of age of acquisition and age of reading for 200 verbs. Together with lemma and type frequencies from public lexical databases, all measures can be downloaded along with this article. Statistical analyses indicate that verb family size, morphological complexity, frequency, and verb regularity affect the semantic transparency and relatedness ratings as well as the age of acquisition estimates, indicating that these are relevant variables in psycholinguistic experiments. Although lexical paraphrases, vector-based similarity measures, and semantic association ratings may deliver complementary information, the interrater reliability of the semantic association ratings for each verb pair provides valuable information when selecting stimuli for psycholinguistic experiments.     

Differences in Noun and Verb Processing in Lexical Decision Cannot be Attributed to Word Form and Morphological Complexity Alone

It has been suggested that the effect of word category in noun and verb processing reflects typical word class properties, which can be characterized in terms of semantic as well as syntactic and morphological features. The present study is aimed at differentiating and discussing the relative contribution of these aspects with a main focus on syntactic and morphological processing. Experiment 1 established a processing advantage for nouns in German visual lexical decision, using nouns denoting biological and man-made objects as compared to transitive and intransitive verbs. Experiment 2 showed that the noun advantage persisted even when the morphological differences between word categories were reduced by using identical suffixes in nouns and verbs. Overall results suggest that the processing differences cannot be reduced to variables such as frequency, word form, or morphological complexity. Reaction time differences between transitive and intransitive verbs strengthen the role of syntactic information. In line with previous accounts the observed effects are discussed in terms of a category-specific combination of linguistic parameters.     

Verb processing during sentence comprehension in aphasia

This study examines verb processing during on-line sentence comprehension in aphasia. We describe two experiments that explore whether a group of Broca's aphasics, who were agrammatic in comprehension as well as speech, a group of fluent aphasics, and a group of normal controls are sensitive to the argument structure arrangements of verbs. Subjects had to perform a complex secondary task both in the immediate vicinity of the verb and also at a point well past the verb while listening to sentences for meaning. Reaction times to this secondary task show that both normal controls and agrammatic Broca's aphasic subjects activate multiple argument structure possibilities for a verb in the vicinity of the verb, yet at a point downstream from the verb such effects disappear. These data suggest that the problems agrammatic subjects show with verbs in sentence comprehension, and the general lexical access deficit also recently claimed to be part of the agrammatics' problem, may not extend to the real-time processing of verbs and their arguments. Fluent aphasic subjects, on the other hand, do not show sensitivity to the argument structure properties of verbs, suggesting that these patients may have a semantic-like sentence processing deficit.     

The noun-verb problem in Chinese aphasia.

Previous studies have shown that Broca's aphasics experience a selective difficulty with action naming inside or outside of a sentence context. Conversely, it has been suggested that Wernicke's aphasics are particularly impaired in object naming. A number of explanations have been offered to account for this double dissociation, including grammatical accounts according to which the main verb problem in agrammatic Broca's aphasics is viewed as a by-product of their syntactic and/or morphological impairment, due perhaps to the greater morphological load carried by verbs (compared with nouns). In the Chinese language, there are no verb conjugations and no declensions. Hence there is no reason to expect a relationship between morphological impairment and deficits in action naming. We examined comprehension and production of object and action names, outside of a sentence context, in a sample of Chinese-speaking Broca's and Wernicke's aphasics. There was an interaction between patient group and object/action naming, but no corresponding interaction on the comprehension task. We conclude that action-naming deficits in Broca's aphasia (and/or the corresponding sparing of action names in Wernicke's aphasia) cannot be attributed to morphological differences between nouns and verbs. We also found a sublexical variant of the noun/verb dissociation applied to the internal structure of compound words made up of a verbal and a nominal element: Broca's aphasics tended to lexicalize the verbal portion of these words more often than the nominal compound, while Wernicke's showed the opposite pattern. These sublexical effects are difficult to explain in syntactic terms nor do they fit the standard lexical view. A modified lexical account is proposed, emphasizing semantic/conceptual effects in a distributed lexicon.     

How toddlers begin to learn verbs

Any theory of language must account for how children learn verbs, the gateway to grammar. Yet verbs can be difficult to learn. Building on Gentner's 'natural partitions hypothesis' we suggest that, to learn a verb, infants must conceptualize components of events and map verbs in the ambient language onto those components. Although toddlers detect and categorize at least some of the conceptual underpinnings of verb categories, the mapping of verbs onto these representations is not transparent. Mapping is a difficult problem in its own right. The Emergentist Coalition Model that has been used to explain noun learning also begins to explain how children move from perceptual to social and then to linguistic information to link verbs to actions and events.     

Syntactic frame and verb bias in aphasia: plausibility judgments of undergoer-subject sentences

This study investigates three factors that have been argued to define "canonical form" in sentence comprehension: Syntactic structure, semantic role, and frequency of usage. We first examine the claim that sentences containing unaccusative verbs present difficulties analogous to those of passive sentences. Using a plausibility judgment task, we show that a mixed group of aphasics performed significantly better on unaccusatives than on passives. We then turn to the observation that passives are generally harder than actives for aphasics. We show that this effect is modulated by lexical bias, i.e., the likelihood that a verb appears in a given syntactic structure: Passives of passive-bias verbs were significantly easier than passives of active-bias verbs. More generally, sentences whose structure matches the lexical bias of the main verb are significantly easier than sentences in which structure and lexical bias do not match. These findings suggest that "canonical form" reflects frequency and lexical biases.