Grammatical Encoding in Aphasia: Evidence from a “Processing Prosthesis”

Agrammatic aphasia is characterized by severely reduced grammatical structure in spoken and written language, often accompanied by apparent insensitivity to grammatical structure in comprehension. Does agrammatism represent loss of linguistic competence or rather performance factors such as memory or resource limitations? A considerable body of evidence supports the latter hypothesis in the domain of comprehension. Here we present the first strong evidence for the performance hypothesis in the domain of production: an augmentative communication system that markedly increases the grammatical structure of agrammatic speech while providing no linguistic information, functioning merely to reduce on-line processing demands. Copyright 2000 Academic Press and Unisys Corporation.     

Grammatical Morphemes and Conceptual Structure in Discourse Processing

The present paper analyzes how the semantic and pragmatic functions of closed class categories, or grammatical morphemes (i.e., inflections and function words), organize discourse processing. Grammatical morphemes tend to express a small set of conceptual distinctions that organize a wide range of objects and relations, usually expressed by content or open class words (i.e., nouns and verbs), into situations anchored to a discourse context. Therefore, grammatical morphemes and content words cooperate in guiding the construction of a situation model during discourse comprehension by specifying complementary aspects of described situations. The paper reviews and extends analytical and empirical evidence for this grammatical-conceptual correspondence, and suggests that the correspondence developed in response to the cognitive demands of discourse processing. Thus the distinction between open and closed linguistic categories is interpreted in terms of a fundamental correspondence between conceptual and linguistic structure that helps organize discourse processing.     

Revise and resubmit: How real-time parsing limitations influence grammar acquisition

We present the results from a three-day artificial language learning study on adults. The study examined whether sentence-parsing limitations, in particular, difficulties revising initial syntactic/semantic commitments during comprehension, shape learners’ ability to acquire a language. Findings show that both comprehension and production of morphology pertaining to sentence argument structure are delayed when this morphology consistently appears at the end, rather than at the beginning, of sentences in otherwise identical grammatical systems. This suggests that real-time processing constraints impact acquisition; morphological cues that tend to guide linguistic analyses are easier to learn than cues that revise these analyses. Parallel performance in production and comprehension indicates that parsing constraints affect grammatical acquisition, not just real-time commitments. Properties of the linguistic system (e.g., ordering of cues within a sentence) interact with the properties of the cognitive system (cognitive control and conflict-resolution abilities) and together affect language acquisition.     

Language Development in Children with Simple-Partial Left-Hemisphere Epilepsy

The nature of cerebral involvement in the acquisition of language was addressed in this longitudinal study of children with an early diagnosis of epilepsy with simple-partial seizures (SPE) and with epileptogenic foci localized in the left frontal (LF) lobe. Yearly evaluations of six SPE-LF children on tests of linguistic comprehension (pointing, understanding of narrative, and understanding of prepositions) and production (repetition, lexical diversity, and grammatical production) were carried out between the ages of 3 and 8 years and compared to those of large samples of control children on the same tasks and at each age level. Linguistic production of all children were transcribed, coded, and analyzed using the Child Language Data Exchange System (MacWhinney & Snow, 1991). Individual evolution trajectories revealed that SPE-LF children showed a clear dissociation in linguistic performance between comprehension and production. Linguistic comprehension gradually improved to reach normal performance levels by age 7 while linguistic production, even at later stages, remained quite poor. This dissociation in the development of linguistic performance in SPE-LF children suggests a complex interplay between brain maturation dynamics and dysfunction modulating the succession of stages in language development. The observed persistent deficits in specific aspects of linguistic performance argue for an early involvement of the anterior areas of the left cerebral hemisphere in the production of language.     

Syntactic priming: Investigating the mental representation of language

We argue that psycholinguistics should be concerned with both the representation and the processing of language. Recent experimental work on syntax in language comprehension has largely concentrated on the way in which language is processed, and has assumed that theoretical linguistics serves to determine the representation of language. In contrast, we advocate experimental work on the mental representation of grammatical knowledge, and argue that sybtactic priming is a promising way to do this. Syntactic priming is the phenomenon whereby exposure to a sentence with a particular syntactic construction can affect the subsequent processing of an otherwise unrelated sentence with the same (or, perhaps, related) structure, for reasons of that structure. We assess evidence for syntactic priming in corpora, and then consider experimental evidence for priming in production and comprehension, and for bidirectional priming between comprehension and production. This in particular strongly suggests that priming is tapping into linguistic knowledge itself, and is not just facilitating particular processes. The final section discusses the importance of priming evidence for any account of language construed as the mental representation of human linguistic capacities.The order of the first two authors is arbitrary. H.B. is supported by an EPSRC Postgraduate Studentship. M.P. is supported by a British Academy Postdoctoral Felowship. S.L. is supported by a University of Nottingham Postdoctoral Fellowship. A.S. was supported by British Academy Research Grant awarded to M.P. T.U. is in part supported by a Mellon Science Development Grant. We would like to thank Dave Elmes, Tyler Lorig, Matt Traxler, an anonymous reviewer, and members of the Sentence Processing Group, Human Communication Research Centre, Universities of Edinburgh and Glasgow.     

Is language acquired through imitation?

The role of imitation in language acquisition is examined, including data from the psycholinguistic, operant, and social learning areas. From the psycholinguistic data, four empirical statements have been extracted: (1) there is no evidence that spontaneous imitations of adult speech influence grammatical development, (2) imitation of speech does not appear to occur with frequency beyond age 3 years, (3) speech and hence imitation are not necessary for the comprehension of linguistic structures, and (4) most utterances of a child are novel and therefore could not have been exactly modeled. The first and second propositions are seen to be based on a too restrictive definition of imitation-immediate and exact copying. Selective imitation-a functional relationship involving similarity of a particular form or function of the model's responses-is proposed as an alternative, thus leaving the validity of statements (1) and (2) in question. Concerning assertion (4), certain data from the operant literature are presented as evidence of the compatibility of novel responding and modeling, imitation, and reinforcement. Finally, it is proposed that statement (3) suggests a mechanism by which selective imitation can be understood. A three-stage process is proposed in which comprehension of a grammatical form sets the stage for selective imitation of that structure, which leads in turn to spontaneous production. Thus imitation is a process by which new syntactic structures can be first introduced into the productive mode.     

No grammatical gender effect on affective ratings: evidence from Italian and German languages

In this study, we tested the linguistic relativity hypothesis by studying the effect of grammatical gender (feminine vs. masculine) on affective judgments of conceptual representation in Italian and German. In particular, we examined the within- and cross-language grammatical gender effect and its interaction with participants’ demographic characteristics (such as, the raters’ age and sex) on semantic differential scales (affective ratings of valence, arousal and dominance) in Italian and German speakers. We selected the stimuli and the relative affective measures from Italian and German adaptations of the ANEW (Affective Norms for English Words). Bayesian and frequentist analyses yielded evidence for the absence of within- and cross-languages effects of grammatical gender and sex- and age-dependent interactions. These results suggest that grammatical gender does not affect judgments of affective features of semantic representation in Italian and German speakers, since an overt coding of word grammar is not required. Although further research is recommended to refine the impact of the grammatical gender on properties of semantic representation, these results have implications for any strong view of the linguistic relativity hypothesis.     

The temporal structure of spoken sentence comprehension in Chinese

Three experiments with 60 native Chinese speakers were conducted to examine the temporal structure of spoken sentence comprehension in Chinese. In the two sentence-gating experiments, listeners heard sentence fragments of various sizes, either successively or individually, and decided on the agent role of the sentence. In the agent-naming experiment, listeners repeated aloud the sentence agent upon hearing the sentence. Converging evidence was derived from these experiments indicating the usefulness of sentence gating in tapping into the temporal structure of comprehension and in evaluating listeners’ comprehension on the basis of partial information. Results from these experiments show that partial sentence information plays a very important role in Chinese sentence comprehension, and that Chinese listeners integrate incomplete and ungrammatical sentence fragments by reference to complete and grammatical models in the language. It is argued that these processing characteristics reflect properties of the Chinese language in which few morphological, grammatical, and syntactic constraints are placed on the relationships between sentence constituents.     

Sentence comprehension in Parkinson's disease: the role of attention and memory.

Sentence comprehension is a complex process involving at least attentional, memory, grammatical, and semantic components. We report three experiments designed to evaluate the impairments underlying sentence comprehension difficulties in nondemented patients with Parkinson's disease (PD). In the first experiment, we asked patients to answer simple questions about sentences which varied in terms of grammatical complexity and semantic constraint. We found that PD patients are significantly compromised in their ability to perform this task. Their difficulties became more prominent as grammatical complexity increased, but they were significantly assisted by semantic constraints that limited possible interpretations of a sentence. Analyses of individual patient profiles revealed heterogeneous performance across the group of PD patients and somewhat inconsistent performance for patients across testing sessions. In the second experiment, we tested the possibility that patients' heterogeneous performance on the sentence comprehension task is due to an impairment in memory or attention, cognitive domains known to be compromised in some PD patients. Although PD patients and control subjects differed on one memory measure, there were no significant correlations between attention and memory performance and the results of the sentence comprehension task. In the final experiment, we manipulated the sentences used in the first experiment in a fashion that stressed the need for memory and attention in a sentence. The results indicated that PD patients are significantly compromised in their ability to attend to certain critical grammatical features of a sentence. A regression analysis identified specific grammatical, semantic, and attentional mechanisms as significant contributors to PD patients' overall sentence comprehension, accounting for over 97% of the variance in their performance. We conclude that there are multiple sources of cognitive difficulty underlying PD patients' sentence comprehension impairment.     

The development of Japanese passive syntax as indexed by structural priming in comprehension

A number of previous studies reported a phenomenon of syntactic priming with young children as evidence for cognitive representations required for processing syntactic structures. However, it remains unclear how syntactic priming reflects children's grammatical competence. The current study investigated structural priming of the Japanese passive structure with 5- and 6-year-old children in a visual-world setting. Our results showed a priming effect as anticipatory eye movements to an upcoming referent in these children but the effect was significantly stronger in magnitude in 6-year-olds than in 5-year-olds. Consistently, the responses to comprehension questions revealed that 6-year-olds produced a greater number of correct answers and more answers using the passive structure than 5-year-olds. We also tested adult participants who showed even stronger priming than the children. The results together revealed that language users with the greater linguistic competence with the passives exhibited stronger priming, demonstrating a tight relationship between the effect of priming and the development of grammatical competence. Furthermore, we found that the magnitude of the priming effect decreased over time. We interpret these results in the light of an error-based learning account. Our results also provided evidence for prehead as well as head-independent priming.     

Suprasegemental and grammatical control over telegraphic speech in young children

The experiment was designed to test the Brown and Fraser (1963) telegraphic speech hypothesis: that children imitate more content words than function words because of linguistic stress associated with content words in English. Thirty-six children aged 18–36 months were assigned to six treatment groups blocked for linguistic development and were asked to imitate ten simple declarative sentences. In each of five experimental conditions, suprasegmental or grammatical features were systematically manipulated. Results contradicted the Brown and Fraser hypothesis: suprasegmental variables did not influence telegraphic speech production significantly. Imitation strategies were, instead, dependent on grammatical hierarchy.     

Assessing resource demands during sentence processing in Parkinson's disease

Patients with Parkinson's disease (PD) have sentence comprehension difficulty, but it is unclear whether this is due to a deficit in grammatical processing or to an executive resource limitation. To assess grammatical processing in PD while minimizing task-related demands, PD patients and healthy control subjects performed a word detection procedure that assesses sensitivity to grammatical agreements in sentences in an "on-line" fashion. With this technique, we found that control subjects and PD patients are equally sensitive to grammatical agreement violations in sentences. A traditional, resource-demanding measure of sentence comprehension was also administered to the same PD patients. In comparison to healthy controls, PD patients were significantly impaired in their relative comprehension of sentences containing object-gap subordinate clauses compared to subject-gap subordinate clauses. Performance on several executive resource measures was also impaired in PD, and this correlated with their comprehension performance. Sensitivity to grammatical agreements with the word detection procedure, in the context of sentence comprehension difficulty on a traditional measure, suggests that PD patients' executive resource limitations contribute to their sentence comprehension difficulty.     

Language deficits, localization, and grammar: evidence for a distributive model of language breakdown in aphasic patients and neurologically intact individuals.

Selective deficits in aphasic patients' grammatical production and comprehension are often cited as evidence that syntactic processing is modular and localizable in discrete areas of the brain (e.g., Y. Grodzinsky, 2000). The authors review a large body of experimental evidence suggesting that morpho-syntactic deficits can be observed in a number of aphasic and neurologically intact populations. They present new data showing that receptive agrammatism is found not only over a range of aphasic groups, but is also observed in neurologically intact individuals processing under stressful conditions. The authors suggest that these data are most compatible with a domain-general account of language, one that emphasizes the interaction of linguistic distributions with the properties of an associative processor working under normal or suboptimal conditions.     

Linguistic abilities in patients with prefrontal damage

The language abilities of 21 patients with prefrontal lesions (11 right and 10 left) and 15 matched normal subjects were analyzed, using a linguistic ability test designed to evaluate performance in six areas: automatic language, language production, verbal memory, syntax, derivative words, and comprehension of logical grammatical structures. Significant differences in the obtained scores of all groups were found. In spite of formal conservation of language in patients with frontal damage, their complex and conceptual verbal abilities were severely compromised.     

Influence of linguistic complexity,rate of presentation,and interphrase pause time on auditory-verbal comprehension of adult aphasic patients

Among the variables affecting comprehension of linguistic stimuli by aphasic subjects are syntactic complexity and processing time. Comprehension performance of 15 aphasic adults was studied while altering the rate of speech presentation and varying the pause time between the major phrases within sentences of increasing grammatical complexity.Simple Active Affirmative Declarative Sentences, Negative, and Passive sentences were presented (1) at the rate of 150 words per minute (wpm) with 1-sec interphrase pause time (IPT); (2) 150 wpm with no pauses; (3) 120 wpm with 1-sec IPT; (4) 120 wpm with no pauses added.Performance was seen to vary with increasing syntactical complexity and as a function of processing time. Greater comprehension was seen with active affirmative than negative; greater with passive affirmative than with active negative. Clinical implications are discussed. Subjects demonstrated greater comprehension when sentences were presented at slower than normal rate; addition of interphrase pause time intervals aided comprehension. Combining slower rate of presentation and IPT intervals provided greatest increase in auditory processing time and showed concomitant increase in comprehension performance.     

The development of children's understanding of "because" and "so"

Children's (5 years, 8 months to 8 years, 4 months) comprehension of "because" and "so" was assessed on both enactment and sentence completion tasks. The use of a within-subject design permitted performance on each task to be interpreted in terms of performance on the other. The pattern of results provided evidence against a componential model for the acquisition of causal connectives. This model holds that the two meaning components (cause, order) are acquired separately, with the order component being acquired several years later than the causal component. The results also were in accord with predictions derived from a contextual model of children's developing understanding of terms expressing logical relationships. This model posits that the understanding of relational terms is initially context dependent, such that children can understand relational terms when they express familiar relationships, but experience difficulty in forming representations of novel relationships solely on the basis of linguistic input. The lexical components of because and so are understood during the context-dependent stage, and the transition from context-dependent to context-independent understanding does not reflect further lexical development, but rather increasing facility in dealing with decontextualized linguistic input.     

Morphological priming by itself: A study of Portuguese conjugations

Does the language processing system make use of abstract grammatical categories and representations that are not directly visible from the surface form of a linguistic expression? This study examines stem-formation processes and conjugation classes, a case of ‘pure’ morphology that provides insight into the role of grammatical structure in language processing. We report results from a cross-modal priming experiment examining 1st and 3rd conjugation verb forms in Portuguese. Although items were closely matched with respect to a range of non-morphological factors, distinct priming patterns were found for 1st and 3rd conjugation stems. We attribute the observed priming patterns to different representations of conjugational stems, combinatorial morphologically structured ones for 1st conjugation and unanalyzed morphologically unstructured ones for 3rd conjugation stems. Our findings underline the importance of morphology for language comprehension indicating that morphological analysis goes beyond the identification of grammatical morphemes.     

Linguistic and nonlinguistic priming in aphasia

Studies of real-time processing in aphasia suggest that linguistic symptoms may be due to deficits in activation dynamics rather than loss of linguistic knowledge. To investigate the domain specificity of such processing deficits, we compared performance by Italian-speaking fluent aphasics, nonfluent aphasics, and normal controls in a linguistic priming task (grammatical gender) with their performance in a color-priming task that requires no verbal mediation. Normal or larger than normal color-priming effects were demonstrated in both aphasic groups. Gender priming did not reach significance in either group, even though the patients displayed above-chance sensitivity to gender class and gender agreement in their accuracy scores. The demonstration of spared gender knowledge despite impaired gender priming underscores the utility of on-line techniques in the study of aphasia. The demonstration of spared color priming suggests that priming deficits in aphasia are either (1) specific to speech and language or (2) specific only to those sensorimotor and attentional processes that language shares with other nonlinguistic systems.     

Argument structure and the child's contribution to language learning

One of the oldest questions in cognitive science asks whether children are able to learn language (or anything) because they are equipped with a very powerful general-purpose learning mechanism or because they are equipped with a domain-specific constrained language acquisition device. Recent advances in statistical approaches to language learning seem to boost the plausibility of general-purpose learning. However, in this article we propose that in the domain of verb learning, children rely more on their internally generated preconceptions about linguistic structure than on robust cues in the input, suggesting that at least in this aspect of language learning, domain-specific grammatical knowledge guides linguistic development.     

TELLING SOMETHING WE CAN'T KNOW:

An interpersonal verb such as annoy or admire can be categorized according to whether its grammatical subject or grammatical object initiates the interaction described by the verb Such a verb can also be categorized according to whether a derived adjective describes its grammatical subject (eg., annoying ) or its grammatical object (eg., admirable ) Although there has been much speculation (eg., Brown & Fish, 1983) that these and other characteristics of these verbs shed light on basic principles of human social interaction, we argue that research to date has failed to demonstrate directly any real-time consequences of these verbs during language comprehension. We present evidence that the initiating-reacting distinction predicts on-line changes in the accessibility of these verbs' arguments, but that the existence of a derived adjective does not. We conclude that tasks that question subjects explicitly about language may fail to reflect the ordinary processes of language comprehension