A mapping theory of agrammatic comprehension deficits

This paper offers evidence for the Isomorphic Mapping Hypothesis, which holds that individuals with agrammatic aphasia tend to have difficulty comprehending sentences in which the order of NPs is not aligned with the structure of the corresponding event. We begin by identifying a set of constructions in English and Korean for which the IMH makes predictions distinct from those of canonical order and trace-based theories of agrammatic comprehension. Then, drawing on data involving the interpretation of those patterns by English-speaking and Korean-speaking agrammatics, we argue for the conceptual and empirical superiority of the isomorphic mapping account.     

Contrasting cases of Italian agrammatic aphasia without comprehension disorder

This study examined the effects of different concurrent verbal memory loads on a recognition accuracy task using bilaterally presented nouns. Four different memory load conditions were examined. They varied along a size dimension of either three or six words and along a complexity dimension of either easy concrete nouns or difficult highly abstract nouns. In each of the above conditions and in one control group, order or word report was controlled and in a second control group subjects were free to report the lateralized words in any order they wished. There were 20 subjects in each of the six groups. As expected, a significant right visual field superiority for verbal processing was obtained. there were no main effects of size of memory load nor complexity of m emory load on the laterality patterns. More subtle fluctuations in the patterns were found in the form of significant interactions between memory load, order of word report, and visual field. These interaction effects suggest that words reported second in the bilateral task, are more susceptible to the interfering effects of either larger or more complex memory loads. This is particularly true for right visual field words. While these data generally support a structural model of hemispheric organization, the interaction effects suggest that modifications must be made to the basic model to account for such factors as hemispheric capacity limits and order of report in the bilateral task.     

On comprehension of active/passive sentences and language processing in a Polish agrammatic aphasic

This paper presents the results of a study of active/passive sentence comprehension by a Polish-speaking agrammatic aphasic. The patient showed good performance on canonically ordered active and passive structures, but performed poorly on inverted variants. The systematically normal and deviant comprehension patterns observed are accounted for by normal interpretative strategies applied to syntactic structures built around verbs with reduced inflectional morphology. The differences between our Polish data and the English data discussed in the literature are explained by the fact that Polish possesses a richer derivational verb morphology. The interpretation of inverted sentences demonstrates the importance of S-V-O word order preference. Our analysis draws upon the notion of grammatical functions to explain the data.     

Action comprehension: deriving spatial and functional relations

A perceived action can be understood only when information about the action carried out and the objects used are taken into account. It was investigated how spatial and functional information contributes to establishing these relations. Participants observed static frames showing a hand wielding an instrument and a potential target object of the action. The 2 elements could either match or mismatch, spatially or functionally. Participants were required to judge only 1 of the 2 relations while ignoring the other. Both irrelevant spatial and functional mismatches affected judgments of the relevant relation. Moreover, the functional relation provided a context for the judgment of the spatial relation but not vice versa. The results are discussed in respect to recent accounts of action understanding.     

Thematic analysis in agrammatic comprehension: syntactic structures and task demands.

Aphasics' ability to assign thematic roles during sentence comprehension was investigated. The study was motivated by the hypothesis that capacity limitations, e.g., due to slowed processing operations, interact systematically with certain aspects of structural analysis more than with others. Experiments using a sentence-picture matching paradigm were conducted with several agrammatic Broca's and paragrammatic Wernicke's patients. Experiment 1 tested comprehension of various syntatic structures. The astoundingly good performance in Experiment 1 for both patient groups was attributed to the low task demands of the experiment. Raising the task demands, by delaying presentation of the relevant picture set in Experiment 2, resulted in a significant decrement of comprehension performance for agrammatic Broca's aphasics, but not for Wernicke's aphasics. Putting the main verb in the sentence-final position, as in Experiment 3, affected Wernicke's aphasics', but not Broca's aphasics' performance. In principle, one explanation for the performance differences between Experiments 1 and 2 for Broca's patient might be a deficit in these patients' verbal memory capacity. Therefore, verbal memory span on different word categories was tested in an additional experiment. No difference, however, was found between the Broca's patients' and the Wernicke's patients' capacity for verbal memory despite their different sentence comprehension profiles. The present data are taken to support the view that Broca's aphasics' comprehension behavior is due to the processing demands imposed by structural inference chains and not to a general reduction in verbal memory.     

Assignment of thematic roles to nouns in sentence comprehension by an agrammatic patient

We present the results of a study of sentence comprehension in an agrammatic patient. The patient showed striking regularities in interpreting a wide variety of sentence structures. We analyze her performance as the result of attempting to interpret a simplified syntactic structure, consisting of a linear sequence of lexical categories, according to a number of simple interpretive strategies.     

Patterns of comprehension performance in agrammatic Broca's aphasia: a test of the Trace Deletion Hypothesis

We tested the core prediction of the Trace Deletion Hypothesis (TDH) of agrammatic Broca's aphasia, which contends that such patients' comprehension performance is normal for active reversible sentences but at chance level for passive reversible sentences. We analyzed the comprehension performance of 38 Italian Broca's aphasics with verified damage to Broca's area, who completed sentence-to-picture matching tasks using active and passive reversible sentences as stimuli. The results failed to confirm the predictions made by TDH: only a small minority (15%) performed at chance on passive sentences and better than chance on active sentences. Furthermore, the distribution of the 38 subjects' performance on passive sentences differed from that predicted by the TDH since many more subjects performed at better-than-chance levels than expected. We discuss the implication of these results for claims about the distribution of language processing mechanisms in the brain.     

On deriving aspectual sense

In his recent article “Verbs, Time and Modality,” M. J. Steedman (1977) proposes a recursive scheme for identifying the aspectual character of a proposition. The purpose of this squib is to point out some faults and gaps in that account that may suggest some interesting directions for future research.     

On deriving essence from existence

A definition of ‘alienation’ is proposed which is a rational reconstruction of the term as it is used in primarily moral contexts. Special attention is given to the Marxist tradition. It is argued that the earliest, moral form of Marx's economic determinism can be expressed in terms of the principle of the sufficiency of unalienated labor. In this connection four main kinds of alienation are distinguished. In the final section, it is argued that while ‘alienation’ has and should have an important theoretical role in the context of moral discourse, social scientists, and in particular sociologists, would be better off if they eliminated ‘alienation’ from their scientific vocabulary.     

On the temporal course of gap-filling during comprehension of verbal passives

The work presented in this paper examines the time course of antecedent reactivation following movement gaps found in passive sentences. Using a cross-modal lexical priming technique, (re) activation of the subject noun phrase (NP) was examined at various critical points following the verb (near the posited gap) for verbal passive sentences and for active (control) sentences. Subjects made lexical decisions to visual targets that were presented at three locations during auditory sentence comprehension: immediately after the matrix verb, 500 msec after the verb, or 1000 msec after the verb. Responses to targets related to the subject NP were faster than those to controls during passive sentences (gap sentences), but not during active sentences (no-gap sentences), thus indicating that reactivation of the matrix subject did occur in the passive cases. Furthermore, the magnitude of the priming increased with distance and time from the verb, going from a nonsignificant trend at the verb to a highly significant effect at 1000 msec following the verb. These results are discussed in terms of both formal and processing models of language.The authors wish to thank Janet Nicol for her contributions to the materials and design of this experiment. This work was supported in part by NIDCD Grant DC01947 and by a University of Washington grant to the first author and an AFOSR grant (AFOSR 91-0225) to the second author.     

On the parity of structural persistence in language production and comprehension

Structural priming creates structural persistence. That is, differences in experience with syntax can change subsequent language performance, and the changes can be observed in both language production and comprehension. However, the effects in comprehension and production appear to differ. In comprehension, persistence is typically found when the verbs are the same in primes and targets; in production, persistence occurs without verb overlap. The contrast suggests a theoretically important hypothesis: parsing in comprehension is lexically driven while formulation in production is structurally driven. A major weakness in this hypothesis about comprehension-production differences is that its empirical motivation rests on the outcomes of experiments in which the priming manipulations differ, the primed sentence structures differ, and the measures of priming differ. To sharpen the comparison, we examined structural persistence with and without verb overlap in both reading comprehension and spoken production, using the same prime presentation procedure, the same syntactic structures, the same sentences, and the same participants. These methods yielded abstract structural persistence in comprehension as well as production. A measure of the strength of persistence revealed significant effects of priming and verb overlap without significant comprehension—production differences. This argues for uniformity in the structural mechanisms of language processing.     

On the universality of language comprehension strategies: evidence from Turkish

A fundamental question in psycholinguistic research concerns the universality of comprehension strategies. We investigated this issue by examining the so-called "subject preference" in Turkish, a language which allows for a natural (unmarked) object reading of an initial ambiguous argument. Using event-related brain potentials (ERPs), we observed increased processing difficulty in the form of a broadly distributed positivity when an initial ambiguous argument was disambiguated towards an object reading. This effect was independent of the animacy (i.e. semantic subject prototypicality) of the ambiguous argument. Our results therefore speak in favour of a universal tendency to interpret the first argument encountered as the "subject" of the clause, even in languages providing no obvious structural motivation for such a strategy. However, we argue that the underlying explanation for this preference must be modified in accordance with cross-linguistic considerations.     

Evaluating the predictive validity of the computerized comprehension task: comprehension predicts production

Until recently, the challenges inherent in measuring comprehension have impeded our ability to predict the course of language acquisition. The present research reports on a longitudinal assessment of the convergent and predictive validity of the MacArthur-Bates Communicative Development Inventories: Words and Gestures (CDI: WG; Fenson et al., 1994, 1993, 2007) and the Computerized Comprehension Task (CCT; Friend & Keplinger, 2003, 2008). The CDI: WG and the CCT evinced good convergent validity; however, the CCT better predicted subsequent parent reports of language production. Language sample data in the 3rd year confirm this finding: The CCT accounted for 24% of the variance in unique word use. These studies provide evidence for the utility of a behavior-based approach to predicting the course of language acquisition into production.     

Negative affects deriving from the behavioral approach system

Does the behavioral approach system (BAS) relate to the experience of any negative affects, or are all negative affects tied to the behavioral inhibition system (BIS)? In Study 1, self-reported Fun Seeking predicted reports of greater frustration and sadness after frustrative nonreward. In Study 2, self-reported Reward Responsiveness predicted reports of greater anger in response to scenarios. In Study 3, self-reported Drive predicted reports of greater anger after the terrorist attacks of September 11, 2001. In no case did BIS sensitivity contribute uniquely to these affects, though BIS predicted nervousness in Study 2 and fear in Study 3. Discussion focuses on the role of frustration and anger in effortful pursuit of goals and depressed affect in disengagement from goals.     

The quantitative analysis of agrammatic production: procedure and data

Despite the long-standing interest in structural aspects of aphasic production, no method has emerged for the systematic analysis of aphasic speech. This paper attempts to address that need by outlining a procedure for the quantitative assessment of narrative speech which yields measures for both morphological and structural characteristics of aphasic production. In addition to complete instructions for carrying out this analysis, data for three groups of subjects are presented: agrammatic aphasics, aphasics who are similarly nonfluent but not clinically judged as agrammatic, and normal controls. While the agrammatics were distinguishable from the nonagrammatic patients on most measures, both nonfluent groups showed comparable reductions in the structural complexity of their propositional utterances. Other findings include indications from individual patient data that aspects of grammatical morphology may dissociate in agrammatism.     

On the relation between representations constructed from text comprehension and transitive inference production

Deductive inference production from texts is a process considered to involve either the construction of an integrated mental model or the step-by-step coordination of propositional representations of the sentences. These alternative hypotheses were tested in 3 experiments using a set inclusion task paradigm in which participants had to recall the premises and to evaluate transitive inferences. Contrary to what is known about linear ordering relations, order of recalls and reaction times provide evidence that the encoding of set inclusion relations does not result in an integrated representation. These results suggest that the mental models theory needs to take account of the nature of the relation to be represented if it is to become a general theory of reasoning.     

A psychometric analysis of functional category production in English agrammatic narratives

Hierarchical models of agrammatism propose that sentence production deficits can be accounted for in terms of clausal syntactic structure [Friedmann, N., & Grodzinsky, Y. (1997). Tense and agreement in agrammatic production: Pruning the syntactic tree. Brain and Language, 56, 397-425; Hagiwara, H. (1995). The breakdown of functional categories and the economy of derivation. Brain and Language, 50, 92-116]. Such theories predict that morpho-syntactic elements associated with higher nodes in the syntactic tree (complementizers and verb inflections) will be more impaired than elements associated with lower structural positions (negation markers and aspectual verb forms). While this hypothesis has been supported by the results of several studies [Benedet, M. J., Christiansen, J. A., & Goodglass, H. (1998). A cross-linguistic study of grammatical morphology in Spanish- and English-speaking agrammatic patients. Cortex, 34, 309-336; Friedmann, N. (2001). Agrammatism and the psychological reality of the syntactic tree. Journal of Psycholinguistic Research, 30, 71-88; Friedmann, N. (2002). Question production in agrammatism: The tree pruning hypothesis. Brain and Language, 80, 160-187], it has also been challenged on several grounds [Burchert, F., Swoboda-Moll, M., & De Bleser, R. (2005a). Tense and agreement dissociations in German agrammatic speakers: Underspecification vs. hierarchy. Brain and Language, 94, 188-199; Lee, M. (2003). Dissociations among functional categories in Korean agrammatism. Brain and Language, 84, 170-188; Lee, J., Milman, L. H., & Thompson, C. K. (2005). Functional category production in agrammatic speech. Brain and Language, 95, 123-124]. In this paper the question of hierarchical structure was re-examined within the framework of Item Response Theory [IRT, Rasch, G. (1980). Probabilistic models for some intelligence and attainment tests (Expanded ed.). Chicago: University of Chicago Press]. IRT is a probabilistic model widely used in the field of psychometrics to model behavioral constructs as numeric variables. In this study we examined production of functional categories (complementizers, verb inflections, negation markers, and aspectual verb forms) in narrative samples elicited from 18 individuals diagnosed with nonfluent aphasia and 18 matched controls. Data from the aphasic participants were entered into an IRT analysis to test (1) whether production of clausal functional categories can be represented as a variable on a numeric scale; and (2) whether production patterns were consistent with hierarchical syntactic structure. Pearson r correlation coefficients were also computed to determine whether there was a relation between functional category production and other indices of language performance. Results indicate that functional category production can be modeled as a numeric variable using IRT. Furthermore, although variability was observed across individuals, consistent patterns were evident when the data were interpreted within a probabilistic framework. Although functional category production was moderately correlated with a second measure of clausal structure (clause length), it was not correlated with more distant language constructs (noun/verb ratio and WAB A.Q.). These results suggest that functional category production is related to some, but not all, measures of agrammatic language performance.     

Mental representation of prepositional compounds: evidence from Italian agrammatic patients

The processing of Prepositional compounds (typical Neo-latin noun--noun modifications where a head noun is modified by a prepositional phrase, e.g., mulino a vento, windmill) was preliminarily studied with a group of six agrammatic aphasic patients, and, in more detail, with a further agrammatic patient (MB). Omission was the most frequent error type in naming, whereas in the other tasks (repetition, reading, writing, and completion) errors were mostly substitutions of the target preposition. This happened even with fully lexicalized compound forms, i.e., those forms where the linking preposition is syntactically and semantically opaque. These findings are interpreted in terms of a dual-route theory of lexical access to morphologically complex words.