Comprehension of reversible sentences in aphasia: the effects of verb meaning

Comprehension of semantically reversible active and passive voice sentences was tested in a timed sentence/picture verification task. Three sets of six verbs were identified that incorporated different features of meaning relevant to the assignment of nouns to the thematic role of agent. Normal control subjects showed an effect of verb set on their response times, with significant effects between sets in the predicted direction. A group of aphasic patients without sentence comprehension disorder also showed a significant effect of verb set despite long and variable response times. A group of patients with reversible comprehension disorder in screening tasks showed weaker effects, primarily because of the use of consistent response biases that ignored the sentence verb. An experimental treatment of active/passive comprehension was conducted with two of these latter patients; one patient reached ceiling in post-testing, and the other showed significant improvement but demonstrated residual comprehension problems that indicated differences across verb sets. Results support the critical importance of verb meaning to normal and aphasic sentence comprehension.     

Treatment of thematic mapping in sentence comprehension: implications for normal processing

Abstract

The inability of some aphasic patients to interpret semantically reversible sentences has been hypothesised to arise from failure to link the grammatical roles of nouns (e.g. subject, object) to their corresponding thematic roles (e.g. agent, patient). Several previous attempts to improve patients' thematic mapping abilities have demonstrated a range of treatment effects of considerable relevance to the development of cognitive models of sentence processing. This study reports a new treatment approach to thematic mapping impairment; it succeeded in improving auditory sentence comprehension in a chronic aphasic patient with a long-standing comprehension deficit. Generalisation of improvement to auditory comprehension of sentences with untreated verbs, to comprehension of written sentences, and to tests using pictorial and videotaped materials not used in treatment, place constraints on the range of possible interpretations of the functional locus of treatment effects. Two areas that did not show significant improvement following treatment included auditory comprehension of sentences lengthened with modifiers, and spoken production of active and passive sentences that express correct thematic roles. These null effects are also interpreted as providing information relevant to models of sentence processing, including the role of working memory in sentence comprehension and the nature of thematic mapping procedures in comprehension and production.     

Agrammatism: An Analysis and Critique,with New Evidence from Four Hebrew-speaking Aphasic Patients

Abstract

We describe and discuss some recent controversies in the analysis of “agrammatic aphasia.” Special attention is paid to the hypothesis that comprehension disorder parallels expressive disorder and to claims that the deficit is best understood in syntactic terms. The thesis of Grodzinsky (1984a; 1986)—that agrammatic patients do not have access to nonlexical nodes in s-structure-is evaluated and applied to four Hebrew-speaking aphasic patients. Two of the patients manifest expressive agrammatism without significant comprehension impairment; two show expressive agrammatism with comprehension impairment that is equally severe for passives with and without the nonlexical element t(race). We argue that both sets of data constitute evidence against Grodzinsky's account of agrammatism.     

A case study of reproduction conduction aphasia II: Sentence comprehension

Abstract

We present data regarding assignment of thematic roles to noun phrases by RL, a reproduction conduction aphasic, in semantically reversible sentences with a variety of syntactic structures. RL makes systematic errors in sentence interpretation. With auditory presentation of sentences, he has difficulty with sentences containing relative clauses in subject position. This is consistent with his having difficulty due to a high local memory load imposed by these structures. With written presentation, RL does not distinguish three sentence types which contain the sequence NP-V-NP-V-NP. His pattern of results suggests that he does not recognise that verbs are embedded or conjoined in the sentence types in question. This may reflect the absence of prosodic cues to syntactic structure in written material. In both modalities, RL has some difficulty with passive morphology, but distinguishes passive from active sentences. The pattern of results with auditory presentation suggests that memory stores and structure-building operations internal to a sentence parser-interpreter are impaired in RL. We consider the relationship between aspects of working memory and sentence parsing-interpretation on the basis of this case and other cases in the recent neuropsychological literature.     

Comprehending how visual context influences incremental sentence processing: Insights from ERPs and picture‐sentence verification

To re‐establish picture‐sentence verification—discredited possibly for its over‐reliance on post‐sentence response time (RT) measures—as a task for situated comprehension, we collected event‐related brain potentials (ERPs) as participants read a subject‐verb‐object sentence, and RTs indicating whether or not the verb matched a previously depicted action. For mismatches (vs. matches), speeded RTs were longer, verb N400s over centro‐parietal scalp larger, and ERPs to the object noun more negative. RTs (congruence effect) correlated inversely with the centro‐parietal verb N400s, and positively with the object ERP congruence effects. Verb N400s, object ERPs, and verbal working memory scores predicted more variance in RT effects (50%) than N400s alone. Thus, (1) verification processing is not all post‐sentence; (2) simple priming cannot account for these results; and (3) verification tasks can inform studies of situated comprehension.     

A capacity approach to syntactic comprehension disorders: making normal adults perform like aphasic patients

Abstract

This paper presents a theory of syntactic comprehension disorders in aphasic patients. In line with some recent proposals, the current theory assumes that aphasic patients still possess the structural (syntactic) and procedural knowledge necessary to perform syntactic analysis. This paper, however, postulates that patients' comprehension deficits originate, at least in part, from reductions in working memory capacity for language. Based on a recently developed theory of capacity constraints in normal language comprehension (Just&Carpenter, 1992), the theory explains how reductions in working memory capacity can lead to the pattern of comprehension breakdown in aphasics, which can be characterised as a conjoint function of the patient's severity level and the structural complexity of the sentence. As supporting evidence for the theory, we report two “simulation” experiments in which we increased the computational demands on normal adults of varying working memory capacities and thereby induced in them the interaction of “severity” by complexity usually observed among aphasic patients.     

Aphasic disorders of syntactic comprehension and working memory capacity

Abstract

Miyake, Carpenter, and Just (1994) present results of two sentence comprehension experiments using RSVP in normal subjects, which they say simulate important features of aphasic patients' comprehension of syntactic structures. On this basis, they claim that normal and aphasic subjects' performance represents a continuum of limitations in working memory capacity. In this paper, we argue that the Miyake et al. data do not resemble the performance of aphasic patients in crucial respects, and that their results provide evidence for the opposite conclusion…namely, that the processing resource system that underlies syntactic processing and that is affected in aphasia is substantially separate from the one used for other verbal tasks, such as reasoning and problem solving, which is tested In tasks such as the Daneman and Carpenter (1980) reading span task.     

Passive reading and motor imagery about hand actions and tool-use actions: an fMRI study

Recent studies have shown that motor activations in action verb comprehension can be modulated by task demands (e.g., motor imagery vs. passive reading) and the specificity of action verb meaning. However, how the two factors work together to influence the involvement of the motor system during action verb comprehension is still unclear. To address the issue, the current study investigated the brain activations in motor imagery and passive reading of verbs about hand actions and tool-use actions. Three types of Chinese verbs were used, including hand-action verbs and two types of tool-use verbs emphasizing either the hand or tools information. Results indicated that all three types of verbs elicited common activations in hand motor areas during passive reading and motor imagery. Contrast analyses showed that in the hand verbs and the tool verbs where the hand information was emphasized, motor imagery elicited stronger effects than passive reading in the superior frontal gyrus, supplemental motor area and cingulate cortex that are related to motor control and regulation. For tool-use verbs emphasizing tools information, the motor imagery task elicited stronger activity than passive reading in occipital regions related to visual imagery. These results suggest that motor activations during action verb comprehension can be modulated by task demands and semantic features of action verbs. The sensorimotor simulation during language comprehension is flexible and determined by the interactions between linguistic and extralinguistic contexts.     

Rasch models of aphasic performance on syntactic comprehension tests

Responses of 42 people with aphasia to 11 sentence types in enactment and sentence–picture matching tasks were characterized using Rasch models that varied in the inclusion of the factors of task, sentence type, and patient group. The best fitting models required the factors of task and patient group but not sentence type. The results provide evidence that aphasic syntactic comprehension is best accounted for by models that include different estimates of patient ability in different tasks and different difficulty of all sentences in different groups of patients, but that do not include different estimates of patient ability for different types of sentences.     

Reduced resources and specific impairments in normal and aphasic sentence comprehension

Abstract

Our recent article (Miyake, Carpenter,&Just, 1994) posits that comprehension breakdown in aphasic patients arises, in part, from reduced working memory resources for language. One issue that we consider in this article concerns the nature of the deficits postulated in the theory, in contrast to two alternative views of the deficit: (1) a proposal cast in terms of a partial loss of knowledge rather than reduced resources, and (2) a proposal that there is a separate resource pool for syntactic processing, rather than a more general pool for language comprehension. A second issue that we address here concerns patterns of selective sparing and impairment among some patients that have often been interpreted as indicating specific impairments in sentence processing operations. We argue that such micro-level dissociations at a fine-grain level of analysis can arise for many reasons other than selective impairments and, more specifically, that the occurrence of analogous patterns in normal adults challenges the common interpretations of double dissociations regarding sentence comprehension deficits.     

Rasch models of aphasic performance on syntactic comprehension tests

Responses of 42 people with aphasia to 11 sentence types in enactment and sentence-picture matching tasks were characterized using Rasch models that varied in the inclusion of the factors of task, sentence type, and patient group. The best fitting models required the factors of task and patient group but not sentence type. The results provide evidence that aphasic syntactic comprehension is best accounted for by models that include different estimates of patient ability in different tasks and different difficulty of all sentences in different groups of patients, but that do not include different estimates of patient ability for different types of sentences.     

Agrammatism as a variable phenomenon

Abstract

With a group of 11 Dutch agrammatic speakers, the studies on production and comprehension of word order by Saffran et al. (1980) and Schwartz et al. (1980) were replicated. We found a pattern of errors that was qualitatively the same as observed by these authors. However, the absolute number of errors was much lower: as a group our agrammatics performed highly above chance. In a second study, we asked seven patients to order various types of sentences in which the position of the verb varied. Again the level of performance was highly above chance. There was no effect of sentence type with respect to verb position (VSO or SOV). Another effect of sentence type, however, was apparent. If the position of the verb could be determined by processing a cue that was within the clause to be ordered, the sentences elicited few errors. Sentences with out-of-clause cues were much more difficult. It seems that there is variability, both between patients and between sentences. A series of possible accounts of this variability is discussed. It is concluded that only some accounts are adequate, in particular those that assume the involvement of memory limitation due to restrictions in space or time. However, even these accounts cannot explain telegraphic speech. Therefore, to supplement them, a new theory of Broca's aphasia is proposed.     

Gist Inference Scores predict gist memory for authentic patient education cancer texts

ObjectivesDevelop a tool to evaluate and improve written medical communication to patients. Determine how effectively Gist Inference Scores (GIS) predict comprehension of patient education texts independently of health literacy. Explicate the text characteristics and psychological mechanism underlying GIS.MethodsFor study 1, a nationally representative sample of older women (N = 61) completed a fill-in-the-blank comprehension task on authentic National Cancer Institute (NCI) texts of varying GIS levels. In study 2, participants (N = 198) read NCI texts (high or low GIS) then recalled what they read.ResultsStudy 1 showed that a higher percentage of different words yielding semantically similar sentence meaning were used to correctly fill-the-blanks on high GIS texts and there was no significant interaction with health literacy. In study 2, a greater proportion of decision-relevant information was recalled for high GIS texts.ConclusionsGIS predicts the likelihood that readers will form gist representations of medical texts on free recall and fill-in-the-blank tasks. High GIS texts allow for more semantic flexibility to mentally represent the same meaning, and more strongly emphasizes gist rather than verbatim representations.Practical implicationsGIS provides medical communicators with an automated and user-friendly method to evaluate medical texts for their ability to convey the bottom-line meaning.     

When task demands induce “asyntactic” comprehension: A study of sentence interpretation in aphasia

Abstract

We investigated sentence processing in two aphasic patients who appeared to have asyntactic comprehension when tested using sentence-picture matching. It was found that neither patient could handle the nonlinguistic cognitive demands of the original task: Specifically, processing two semantically incongruous inputs (sentence plus reverse-role picture) overloaded working memory. Their ability to deal with semantic conflict in the absence of multiple inputs was examined in an interleaved meaning-classification/actor-identification task. The patients rarely accepted misordered sentences like The cheese ate the muse as plausible, but performed poorly when asked to identify the “actors” in such sentences, often selecting the more likely alternative (the mouse). We concluded from this dissociation between tasks that semantic conflict only overtaxed their limited processing capacity when the conflicting options were explicitly available and directly relevant to the decision process. There was, therefore, no adverse effect in meaning classification, where the alternative (lexically-based) sentence reading (1) had to be computed by patients, and (2) bore no direct relevance to the plausibility judgement. By contrast, in actor identification, the patients had to choose between two explicitly available candidates for the actor role, one syntactically based and the other more plausible. Since our patients made errors in identifying actors immediately after correctly classifying sentences with regard to plausibility, we argued that their inaccurate performance under conditions of high processing load was more likely to reflect an inability to perform the necessary decision processes than an impaired capacity to analyse linguistic structure in the face of increased (nonlinguistic) task demands.     

Sentence processing deficits: Theory and therapy

Investigations of sentence processing were carried out using two patients with impairments in comprehending and producing sentences. The deficits observed were interpreted as resulting from impairments to the procedures which map thematic relations in sentence comprehension and production (Schwartz, Linebarger, & Saffran, 1985). Therapy for these mapping disorders was carried out, and as a result of the treatment, improvements were measured in sentence comprehension and production for both patients, despite the fact that they had both been aphasic for at least five years prior to this therapy. The improvement observed was specific to tasks in which mapping of thematic relations is crucial. Impairments in carrying out tasks unrelated to the mapping procedure were not improved by the mapping therapy. Furthermore, therapy was then applied for one of the patients to an untreated function which then improved, suggesting that all the improvements measured were specific effects of the treatment applied.

The results of the sentence-processing therapy lend support to the mapping deficit hypothesis as an interpretation of the deficit shown by some patients in comprehending and producing sentences, but suggest that the mapping of different types of thematic relations should be investigated further.     

Dissociations of lexical function: Semantics,syntax, and morphology

Abstract

Aphasic patients who exhibit “asyntactic comprehension” show poor performance on a sentence-picture matching task with semantically unconstrained sentences, such as “The cow bit the horse,” but good performance, when the sentences are semantically constrained, such as “The boy threw the ball.” The assumption has been that such patients are able to interpret these latter sentences by relying solely on the meanings of the individual words, and that their intact lexical semantics can support some amount of sentence processing. We test this claim by investigating, in detail, the lexical semantics of an aphasic patient (JG), whose speech production is severely agrammatic and whose sentence-picture matching in asyntactic. We explore the semantics of JG's lexicon for both morphologically simple and complex words. We find that word meanings are represented normally in his mental lexicon, and he is able to use this information to integrate words into phrases. In contrast, lexical syntactic and morphological processes are severely impaired. This pattern confirms that lexical semantics can support some limited amount of sentence processing in patients with asyntactic comprehension, and that different lexically based processes can be impaired differentially following brain damage.     

Japanese learners' processing time for reading English relative clauses analyzed in relation to their English listening proficiency

The present study examined Japanese university students' processing time for English subject and object relative clauses in relation to their English listening proficiency. In Analysis 1, the relation between English listening proficiency and reading span test scores was analyzed. The results showed that the high and low listening comprehension groups' reading span test scores do not differ. Analysis 2 investigated English listening proficiency and processing time for sentences with subject and object relative clauses. The results showed that reading the relative clause ending and the main verb section of a sentence with an object relative clause (such as "attacked" and "admitted" in the sentence "The reporter that the senator attacked admitted the error") takes less time for learners with high English listening scores than for learners with low English listening scores. In Analysis 3, English listening proficiency and comprehension accuracy for sentences with subject and object relative clauses were examined. The results showed no significant difference in comprehension accuracy between the high and low listening-comprehension groups. These results indicate that processing time for English relative clauses is related to the cognitive processes involved in listening comprehension, which requires immediate processing of syntactically complex audio information.     

Randomized sham controlled trial of repetitive transcranial magnetic stimulation to the dorsolateral prefrontal cortex for the treatment of panic disorder with comorbid major depression

BackgroundIn an open-label trial low-frequency repetitive transcranial magnetic stimulation (rTMS) to the right dorsolateral prefrontal cortex (DLPFC) significantly improved symptoms of panic disorder and major depression. Here we present data of a randomized double-blind study.MethodsTwenty-five patients were assigned 4 weeks of active or sham rTMS to the right DLPFC. rTMS parameters consisted of 1800 stimuli/day, 1-Hz, at 110% of resting motor threshold. Response was defined as a ≥40% decrease on the panic disorder severity scale and a ≥50% decrease on the Hamilton depression rating scale. At the end of the randomized phase, patients were offered the option of receiving open-label rTMS for an additional 4 weeks.ResultsRepeated-measures ANOVA revealed significantly better improvement in panic symptoms with active compared with sham rTMS, but no significant difference in depression. At 4 weeks, response rate for panic disorder was 50% with active rTMS and 8% with sham. After 8 weeks of active rTMS, response rate was 67% for panic and 50% for depressive symptoms. Repeated-measure ANOVA showed significant improvements in panic disorder, major depression, clinical global impression, and social adjustment. Clinical improvement was sustained at 6-month follow-up.LimitationsLimitation of this study is the relatively small sample size.ConclusionsAlthough 4 weeks of rTMS was sufficient to produce a significant effect in panic symptoms, a longer course of treatment resulted in better outcomes for both panic disorder and major depression. These data suggest that inhibitory rTMS to the right DLPFC affects symptoms expression in comorbid anxiety and depression.ClinicalTrials.gov Identifier: NCT00521352.     

Grammatical class in lexical production and morhpological processing: Evidence from a case of fluent aphasia

We present the case of a fluent aphasic patient who is impaired at producing nouns relative to verbs in picture naming, sentence completion, and sentence generation tasks, but is better at both producing and comprehending concrete nouns than abstract nouns. Moreover, he displays a selective difficulty in producing the plural forms of some nouns and pseudowords presented as nouns, but was able to produce the phonologically identical third-person singular forms of corresponding verb homonyms and of the same pseudowords presented as verbs. This pattern of performance casts doubt on the hypothesis that grammatical class effects are always epiphenomena of more general semantic impairments that affect the naming of actions or of concrete objects, and suggests that these effects may arise instead from damage to syntactic processes pertaining specifically to the grammatical properties of words. We also discuss the implications of such damage for models of morphological processing.     

Grammatical class in lexical production and morhpological processing: Evidence from a case of fluent aphasia

We present the case of a fluent aphasic patient who is impaired at producing nouns relative to verbs in picture naming, sentence completion, and sentence generation tasks, but is better at both producing and comprehending concrete nouns than abstract nouns. Moreover, he displays a selective difficulty in producing the plural forms of some nouns and pseudowords presented as nouns, but was able to produce the phonologically identical third-person singular forms of corresponding verb homonyms and of the same pseudowords presented as verbs. This pattern of performance casts doubt on the hypothesis that grammatical class effects are always epiphenomena of more general semantic impairments that affect the naming of actions or of concrete objects, and suggests that these effects may arise instead from damage to syntactic processes pertaining specifically to the grammatical properties of words. We also discuss the implications of such damage for models of morphological processing.