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PubMed1997

Aphasic sentence comprehension as a resource deficit: a computational approach.

This article describes a new computational model of aphasic sentence comprehension. The model is based on the premise that all aphasics, however different, share a common deficit which determines a considerable amount of the individual variation observed in their sentence comprehension performance. This common deficit is construed as a pathological reduction in the activation resources of a working memory system that subserves sentence comprehension (Miyake, Carpenter, & Just, 1994). To test the theoretical feasibility of the resource reduction hypothesis, a new computer model of aphasic sentence comprehension was developed and tested. We describe the model as well as some initial simulation results, indicating that the model can account for some of the sentence complexity and severity effects that have been reported in the aphasia literature.

Aphasia↗

PubMed1998

Comprehension of famous personal and geographical names in global aphasic subjects.

This experiment compared comprehension of famous personal and geographical names with that of common nouns in three groups of severe aphasic subjects across three modalities. Results revealed that the global aphasic group comprehended famous personal names significantly better than they did common nouns and were better in the reading comprehension modality. Comprehension of famous geographical names in the global aphasic group, however, was as impaired as that of common nouns. CT images suggested that the left occipital lobe and the left posterior inferior temporal gyrus, as well as the right hemisphere, may have relevance to the comprehension of written famous personal names.

Aged↗

PubMed1999

The critical role of group studies in neuropsychology: comprehension regularities in Broca's aphasia.

We reexamine the empirical record of the comprehension abilities of Broca's aphasic patients. We establish clear, commonly accepted, selection criteria and obtain a pool of results. We then subject these results to a detailed statistical analysis and show that these patients comprehend certain canonical sentences (actives, subject relatives, and clefts with agentive predicates) at above-chance levels, whereas comprehension of sentences that contain deviations from canonicity (passives, object-gap relatives, and clefts) is distinct and is at chance. That the latter is the case, and patients indeed guess at such structures, we show by comparing the distribution of individual results in passive comprehension to that of a model for such guessing-an analogous series of tosses of an unbiased coin. The two distributions are virtually identical. We conclude that the group's performance is stable, and well-delineated, despite intersubject variation whose source is now identified. This means that certain comprehension tests may not always be used for the diagnosis of individual patients, but they do characterize the group. It also means that group studies are not just a valid option in neuropsychology; they are a must, since demonstrations like ours indiciate very clearly that single-case studies may be misleading. As we show, the findings from any one patient, without the context of a group, may give a distorted picture of the pathological reality. Our conclusions thus promote studies of groups of brain-damaged patients as a central tool for the investigation of brain/behavior relations.

Aphasia, Broca↗

PubMed1999

Comprehension of contrastive stress by Broca's aphasics.

Comprehension of stress as a determiner of reference for pronouns was compared in eight patients with Broca's aphasia (BA) and five age-matched control subjects. The subjects were asked to listen to sentences in which the stressed or unstressed condition of the pronoun was a critical criterion for the establishment of reference. For each sentence, subjects were shown three pictures and asked to point to the correct referent of the pronoun. While the controls were nearly perfect in both the stressed and unstressed conditions, BA patients were significantly worse than normals, showing chance performance in both cases. However, a significant disparity was found in the BA patients' selection of the object NP as the referent under stressed and unstressed conditions, indicating that BA subjects are, indeed, sensitive to the stress patterns of pronouns. It was thus hypothesized that the BA patients' chance performance was the result of an inability to implement their knowledge of stress during the processing of sentences involving discourse-related linguistic operations, such as the establishment of pronoun reference (Grodzinsky, Wexler, Chien, Marakovitz, & Solomon, 1993). To test this hypothesis, a second experiment was conducted in which discourse-related operations were eliminated. In this second experiment, comprehension of stress by the same two groups was compared in tasks involving purely morphosyntactic processes. The contrastive stress patterns of otherwise homophonous compound nouns and adjectival phrases (e.g., BLACKboard, black BOARD), rather than those of pronouns, were examined. In this grammatically "simpler" experiment (i.e., without discourse-related operations), BA subjects scored significantly above chance in their comprehension of sentences involving compound nouns; unexpectedly, however, these same subjects did not show significantly above-chance performance in their comprehension of sentences containing adjectival phrases. Nevertheless, the results obtained in these two experiments seem to support the view that aphasic patients may have a lack of processing capacity, resulting in more errors during the processing of discourse-related linguistic constructions.

Aged↗

PubMed2001

Agrammatic Broca's aphasia is not associated with a single pattern of comprehension performance.

One influential hypothesis posits that the brain regions implicated in Broca's aphasia are responsible for specific syntactic operations that are necessary for the comprehension and production of sentences (Grodzinsky, 1986, 1990, in press). The empirical basis of this hypothesis is the claim that Broca's aphasics have no difficulty understanding sentences in the active voice (and other "canonical" sentence types, such as subject relatives and clefts with negative predicates), but perform at chance level with passive voice constructions (and other "noncanonical" sentences such as object-gap relatives and object clefts). In the face of well-established results indicating that Broca's aphasics can exhibit several different performance patterns on these sentence types, Grodzinsky, Piñango, Zurif, and Drai (1999) argued that these conflicting results do not challenge the theory when the data are analyzed appropriately. They carried out a creative statistical analysis of the comprehension performance of published cases of Broca's aphasia and concluded that all of these cases are in agreement with the predicted pattern: chance on passives and 100% correct on actives. Here we show that the statistical reasoning adopted by Grodzinsky et al. (1999) is flawed. We also show that the comprehension performance of a substantial number of the Broca's aphasics in their own sample does not conform to the pattern required. Rather, contrary to these authors' claim, Broca's aphasia is not associated with a consistent pattern of sentence comprehension performance, but allows for a number of distinct patterns in different patients.

Aphasia, Broca↗

PubMed2002

Sentence processing strategies in healthy seniors with poor comprehension: an fMRI study.

We used fMRI to examine patterns of brain recruitment in 22 healthy seniors, half of whom had selective comprehension difficulty for grammatically complex sentences. We found significantly reduced recruitment of left posterolateral temporal [Brodmann area (BA) 22/21] and left inferior frontal (BA 44/6) cortex in poor comprehenders compared to the healthy seniors with good sentence comprehension, cortical regions previously associated with language comprehension and verbal working memory, respectively. The poor comprehenders demonstrated increased activation of left prefrontal (BA 9/46), right dorsal inferior frontal (BA 44/6), and left posterior cingulate (BA 31/23) cortices for the grammatically simpler sentences that they understood. We hypothesize that these brain regions support an alternate, nongrammatical strategy for processing complex configurations of symbolic information. Moreover, these observations emphasize the crucial role of the left perisylvian network for grammatically guided sentence processing in subjects with good comprehension.

Aged↗

PubMed1999

Reading comprehension and working memory in learning-disabled readers: Is the phonological loop more important than the executive system?

This investigation explores the contribution of two working memory systems (the articulatory loop and the central executive) to the performance differences between learning-disabled (LD) and skilled readers. Performances of LD, chronological age (CA) matched, and reading level-matched children were compared on measures of phonological processing accuracy and speed (articulatory system), long-term memory (LTM) accuracy and speed, and executive processing. The results indicated that (a) LD readers were inferior on measures of articulatory, LTM, and executive processing; (b) LD readers were superior to RL readers on measures of executive processing, but were comparable to RL readers on measures of the articulatory and LTM system; (c) executive processing differences remained significant between LD and CA-matched children when measures of reading comprehension, articulatory processes, and LTM processes were partialed from the analysis; and (d) executive processing contributed significant variance to reading comprehension when measures of the articulatory and LTM systems were entered into a hierarchical regression model. In summary, LD readers experience constraints in the articulatory and LTM system, but constraints mediate only some of the influence of executive processing on reading comprehension. Further, LD readers suffer executive processing problems nonspecific to their reading comprehension problems.

Child↗

PubMed1980

Cochlear prostheses in use: recent speech comprehension results.

Speech-comprehension tests were performed with several deaf volunteers who were equipped with different cochlear prostheses. These prostheses work with inductive transcutaneous signal transmission and contain a multi-channel scala tympani electrode or, in two cases, a disc electrode situated external to the cochlea in the round window niche. The external portable single-channel speech-processor/transmitter used is the same in all cases. The comprehension (stimulation only, no lip reading) of numbers between 1 and 99 on first contact with the stimulator and therefore without any training was around 38% showing that through well designed single-channel stimulation of the auditory nerve it is possible to generate hearing sensations sounding very much like nature hearing impressions. Some open speech comprehension was reached: Through the help of the stimulator, without lip reading, between 60 and 100% of sentences unknown to the completely deaf volunteer, spoken only a little more slowly than normal, are correctly understood. The percentage for isolated unknown words is 60%. Also an important improvement of word comprehension can be achieved through additional stimulation as compared to unaided lip reading. It appears that the most recent design of our cochlear prosthesis can already be regarded as a useful aid for the deaf.

Adult↗

PubMed1981

Intelligibility and comprehension of time compressed sign language narratives.

A method of time compressing visual displays was devised to assess the effects of compression on the comprehension of American sign language (ASL). Two ASL narratives were visually presented to three groups of deaf ASL users. A compression group was presented narratives compressed to 50% of the duration of the normal rates. A no-compression group was presented narratives signed at normal rates. A pause groups was presented compressed narratives with blank pauses inserted so that the total time per narrative was equal to that of the no-compression versions. Following each narrative, subjects completed a written comprehension task. Comprehension in both compression and pause groups was significantly lower than in the no-compression group. Pauses did not significantly affect scores relative to compression. An additional group of deaf ASL users was presented an intelligibility task in which signs taken from the narratives were presented in isolation either with or without compression. The total number of signs correctly identified was significantly lower with compression. Decrements in comprehension were best explained as the result of cumulative decrements in sign intelligibility and not as the result of decrements in available processing time.

Deafness↗

PubMed1991

The processing of cohesion devices in text comprehension.

The cognitive operations involved in the processing of surface-cohesion devices for the construction of a coherent mental representation is a major issue in text comprehension. An experiment was carried out with two narratives presented in two versions: a high-cohesion version and a low-cohesion version derived from the high version with the use of several devices--two anaphoric markers, changes in the temporal connective and word order, omission of the thematic sentence--without modification of the text content. The subjects read and immediately recalled a high-cohesion text and a low-cohesion text. The results showed that lowering cohesion produced an insignificant increase (8%) in reading time, but a highly significant decrease (25%) in recall performance. It appears that the subjects did not execute the processing required by the cohesion devices. The results are discussed with respect to models of sentence comprehension in comparison with text comprehension and metacognitive aspects of reading comprehension.

Adult↗

PubMed2007

A survey of National Cancer Institute-designated comprehensive cancer centers' oral health supportive care practices and resources in the USA.

BACKGROUND: The oral complications and morbidity resulting from overall cancer therapy utilizing radiation, chemotherapy, and/or stem cell transplantation can have significant impact on a patient's health, quality of life, cost of care, and cancer management. There has been minimal health services research focusing on the status of medically necessary, oral supportive services at US cancer centers. METHODS: A pre-tested, survey questionnaire was distributed to the directors of National Cancer Institute (NCI)-designated comprehensive cancer centers to assess each institution's resource availability and clinical practices, as it relates to the prevention and management of oral complications during cancer treatment. RESULTS: Sixteen of the 39 comprehensive cancer centers responded to the survey. Of the respondents, 56% of the centers did not have a dental department. The sites of delivery of oral supportive care services range from the provision of in-house dental care to community-based, private practice sites. No standard protocols were in place for either oral preventive care or for supportive services for oral complications during or after cancer therapy. Fifty percent of the responding comprehensive cancer centers reported orally focused research and/or clinical trial activities. CONCLUSIONS: Comprehensive cancer care must include an oral care component, particularly for those cancer patients who are at high risk for oral complications. This requires a functional team of oral care providers collaborating closely within the oncology team. Considering the number of cancer patients receiving aggressive oncologic treatment that may result in oral toxicity, the impact of oral conditions on a compromised host, and the potential lack of appropriate resources and healthcare personnel to manage these complications, future research efforts are needed to identify the strengths and weaknesses of present oral supportive care delivery systems at both NCI-designated cancer centers and community-based oncology practices.

Cancer Care Facilities↗

PubMed2005

Examining advocacy and comprehensive cancer control.

The effectiveness of advocacy has been well documented and its use established as a common practice in furthering sound public health policy and practices. Efforts are underway to explain how advocacy has supported, shaped and influenced public policy concerning -- and the growth and development of -- comprehensive cancer control initiatives. The objective of this paper is to assess the history, current role and future of advocacy as a means of articulating the value of, and furthering, comprehensive cancer control practices. Comprehensive cancer control is approaching a critical moment in its development, and a unified approach is necessary to achieve common goals. A call to action for supporting and contributing to the success of a comprehensive approach to cancer control is more important today than it was 11 years ago. Advocacy is an essential strategy in that call to action.

Health Policy↗

PubMed2005

Collaborating to conquer cancer: a comprehensive approach to cancer control.

Despite substantial contributions on the part of public, non-profit, and private sector organizations, the burden of cancer in the United States remains high. As public health organizations, particularly county, state, tribal, and territorial health departments, try to reduce the significant burden of cancer, they face additional issues that make it difficult to address cancer in a comprehensive way. These challenges along with the need to accelerate progress in reducing the U.S. cancer burden, prompted the Centers for Disease Control and Prevention (CDC) and its national partners to begin to work together to further define and describe comprehensive cancer control (CCC) as an approach to reducing the burden of cancer. CCC is defined as "an integrated and coordinated approach to reducing cancer incidence, morbidity, and mortality through prevention, early detection, treatment, rehabilitation, and palliation." This article describes the national effort to support comprehensive cancer control, outlines national and state level success in comprehensive cancer control, and provides a call to action to public, private, and non-profit organizations, governments of all levels, and individuals to renew their commitments to reducing the burden of cancer.

Centers for Disease Control and Prevention, U.S.↗

PubMed1992

Language comprehension in schizophrenics and their brothers.

Disturbances in language functioning may be associated with familial vulnerability to schizophrenia. Language comprehension, measured by the Luria-Nebraska Relational Concepts Factor Scale, was evaluated in 36 schizophrenic probands and their nonschizophrenic adult brothers (n = 41), and in 18 normal controls. Language comprehension performance was a function of psychiatric diagnosis in the brothers. Brothers who met criteria for schizophrenia-spectrum disorders showed significantly reduced language performance compared with unaffected brothers and normal controls. Moreover, abnormal language performance was exhibited by significantly more probands and spectrum-disordered brothers than by the normal controls and the brothers without schizophrenia-spectrum disorders. Finally, language performance was not significantly different for 31 pairs of schizophrenic probands and their brothers. Impaired language comprehension appeared comparatively specific in this sample of relatives, as groups were not significantly different on measures of nonlinguistic concept formation (Wisconsin Card Sorting Test) and general intellectual functioning (WAIS-R Information and Block design). Results suggest that impaired language comprehension is associated with familial vulnerability to schizophrenia, and that this disturbance may be most severe in relatives diagnosed with schizophrenia-spectrum disorders.

Adult↗

PubMed1989

Syntactic loss versus processing deficit: an assessment of two theories of agrammatism and syntactic comprehension deficits.

This research evaluated Grodzinsky's (1984, 1986a) syntactic loss and Kolk and van Grunsven's (1985) working memory impairment explanations of syntactic comprehension deficits in agrammatic aphasics. Four aphasic patients were evaluated who showed different patterns of impairment on morphological and structural aspects of production. The comprehension tasks compared performance on full and truncated passive sentences. The syntactic loss hypothesis predicted worse performance on truncated than full passives, while the working memory deficit hypothesis predicted the reverse. Neither hypothesis was supported, as the patients performed at a similar level on both types of passives. In addition, there was little relation between the patients' production indices and their comprehension level. The results argue against any global theory of agrammatism that attempts to attribute all agrammatic speech and co-occurring syntactic comprehension deficits to the same source.

Aged↗

PubMed1985

Category specificity in an agrammatic patient: the relative impairment of verb retrieval and comprehension.

We report our investigations of a severely agrammatic patient (ROX). A striking feature of ROX's spontaneous speech was his extremely abnormal verb phrase constructions. We established that ROX was impaired both in the retrieval and in the comprehension of action names and verbs which contrasted with his generally excellent comprehension and retrieval of nouns. First we describe his impaired performance on certain sentence comprehension tests. Secondly we document his deficits in naming common actions and our attempt to remedy his impairment. Thirdly we investigate his comprehension of semantically and thematically related nouns and verbs. ROX's agrammatism is discussed from the perspective of category specificity. It is argued that his semantic representation of verbs is impaired, and that this lexical deficit may well be at the core of this type of agrammatism.

Adult↗

PubMed1988

Category and modality specific dissociations in word comprehension and concurrent phonological dyslexia.

A 62-yr-old aphasic patient was found to have a marked auditory comprehension deficit for body parts, colors, numbers and letters in the face of excellent comprehension for all other word categories and virtually intact reading comprehension for all word categories, including those affected by the auditory dissociation. A severe impairment in the graphophonemic route for reading was also discovered. The case is discussed in the context of category-specific dissociations after brain injury and the possible mechanism for failures of body part comprehension.

Anomia↗

PubMed1986

Effects of thematic structure on syntactic comprehension in aphasia.

This study assessed aphasic subjects' sensitivity to the given-new structure within simple paragraphs and the extent to which narrative discourse is facilitative of syntactic processing in the absence of semantic constraints. Subjects were divided into four groups along the dimensions of comprehension level and fluency. Stimulus items consisted of reversible active and passive sentences that were presented in the following three conditions: isolation, at the end of paragraphs such that the given-new structure was respected, and at the end of paragraphs such that the given-new structure was violated. Fluency did not significantly influence performance but comprehension level did. The high-comprehension group presented no significant differences between contextual conditions. The low-comprehension group, however, favored both paragraph contexts over isolation with no difference occurring between contextual conditions. These results suggest that lower level aphasic subjects are able to utilize thematic, antecedent verbal information for comprehending sentences in connected discourse even when the discourse is not semantically predictive of the underlying meaning of these sentences. Whether the narrative respects or violates the given-new relationship may not be an important factor. The reasons for these findings are explored.

Adult↗