Defects of immediate memory in Broca's and conduction aphasia

It has been suggested that the repetition defect seen in conduction aphasia is caused by an auditory immediate memory defect. The purposes of this study were the following: to ascertain whether the finding of an auditory immediate memory defect in conduction aphasia could be replicated, to ascertain whether Broca's aphasics have a similar type of immediate memory defect, and to ascertain whether a relationship exists between immediate memory and comprehension of spoken language. Digits were either spoken or presented visually to Broca's and conduction aphasics. An analysis of span scores reveals that within each group there were no significant differences between the modes of presentation or the response modes. There were no significant differences between the aphasic groups. Comprehension of spoken language significantly correlated with digit span scores.     

Patterns of spontaneous recovery in aphasic groups: A study of adult stroke patients

The recovery of 31 aphasic stroke patients in the first three months postonset was investigated. Improvements on eight comprehension, repetition, and expression tasks were documented for four groups. These groups, retrospectively defined on the basis of initial scores on a fluency and a comprehension task, were: Low Fluency/Low Comprehension (LFLC), Low Fluency/High Comprehension (LFHC), High Fluency/Low Comprehension (HFLC), and High Fluency/High Comprehension (HFHC). Examination of each group's recovery revealed (1) equal improvement on nearly all language tasks for the two High Comprehension groups and (2) a more selective improvement largely in comprehension and imitation tasks for the two Low Comprehension groups. Implications of this selective improvement in initially low comprehending aphasics are discussed.     

Computer tomographic localization, lesion size, and prognosis in aphasia and nonverbal impairment.

Computerized tomography scans (80) were used to localize infarcts in 70 patients. Twenty-three aphasics were scanned within 35 days from onset, 39 beyond a year, and 18 were nondominant cases. Aphasics were also grouped according to test scores obtained within 35 days of scan. Chronic global aphasics have larger lesions than persisting Broca's aphasics. The area of persisting Broca's aphasia is similarly anterior but larger than that of recovered motor aphasia. Anomic aphasics evolve from Broca's and Wernicke's types with differing localization. Lesion size correlated with severity and recovery, and comprehension among the subtests.     

Some aspects of language comprehension in anterior aphasia

The competency of language comprehension was evaluated in three groups: anterior aphasics, posterior aphasics, and normal control subjects. Test material was divided into two sentence groups (Fill in the Blank and True/False) emphasizing either (1) semantic, “real world,” identity words or (2) syntactic, relational words, and one paragraph interpretation task. Matching auditory and visual (written) presentations were given. The control subjects performed almost flawlessly but many errors were made by each aphasia group. Qualitative study revealed a marked difference in the comprehension problem of the two groups. The anterior aphasic group performed well on semantically weighted sentences but made errors on syntactically weighted material, regardless of mode of presentation. In contrast, the posterior aphasics made almost the same number of errors on both types of material, regardless of mode of presentation. These findings support the concept of defective language comprehension in anterior aphasia and further suggest that the defect centers on the syntactical structures which are also poorly handled in expressive output.     

Supra- and infrasylvian conduction aphasia

Fifteen cases of conduction aphasia which were tested with the Aachen Aphasia Test (AAT), are presented. The CT lesion data were transformed to a standard 3D-reference brain referring to the ACPC line. According to the lesion profiles a group of 6 patients had pure suprasylvian lesions, a group of 4 patients had pure infrasylvian lesions, and a group of 5 patients had lesions in both supra- and infrasylvian regions. Suprasylvian conduction aphasics are superior to infrasylvian conduction aphasics in the token test and in repetition tasks. Infrasylvian conduction aphasics use more stereotypes in spontaneous speech than suprasylvian conduction aphasics. Conduction aphasics with both lesion sites perform less well in tests of naming, writing, and comprehension than the pure types. Thus conduction aphasia is a heterogeneous syndrome anatomically and linguistically.     

Crossed dextral aphasia: A clinical radiological correlation

Three lifelong right-handed patients with clinically and radiologically well-defined right-hemispheric infarctions became aphasic. Their language functions in the rehabilitative, subacute phase of their illness were characterized by fluent, literal paraphasic output, dyslexia, and dysgraphia. Auditory comprehension was fair for contextual conversation, and the combination of language abilities enabled them to reach a “functional communication” stage. This study was unable to determine why these three patients had crossed dextral aphasias resulting from their otherwise typical clinical and radiological right-hemispheric infarcts. Of interest, the radiologically well-defined lesions, aside from being ipsilateral, fitted well the “posterior” fluency localization in two of the three patients, but was more extensive in the third.     

Increased susceptibility of aphasics to a distractor task in the recall of verbal commands

The ability of 15 control, 15 nonaphasic brain-damaged, and 15 aphasic patients to carry out three-word commands on the Token Test was studied under three conditions: no delay, 20-sec unfilled delay, and 20-sec delay filled with a counting task. Only aphasics with mild to moderate comprehension deficit participated in the experiment and their scores in the no-delay condition were not inferior to those of the other two groups. The 20-sec unfilled delay did not bring about a decrement of the performance in any group, while all of them were impaired with 20-sec filled delay. The rate of forgetting was, however, significantly greater in aphasics than in patients without language disorders, even when the scores of the no-delay condition were introduced as covariates in the analysis of the filled-delay condition. The same result was obtained when, in a second experiment, 4 sec elapsed between the end of the command and the beginning of the counting activity. The increased susceptibility of aphasics to the disruptive effect of the distractor task is viewed as following a failure in organizing verbal information, a deficit that may contribute to lowering their comprehension level.     

Brain perfusion and neuropsychological test scores: A correlation study in aphasics

In 26 patients suffering from the pure types of aphasias (11 total, 6 motoric, 5 sensory, and 5 amnesic), hemispheric and regional cerebral blood flow were measured and the flow values were correlated with psychological test scores including Wechsler Adult Intelligence Scale (WAIS), Token Test, Benton Test, and word fluency tests. With respect to the flow values, an overall difference between the groups of aphasics was proved by analysis of variance [regional cerebral blood flow (rCBF): F(3,22) = 13.77, p < .001]. The location of mainly impaired brain perfusion was not always confined to the centers within the speech area expected in view of the clinical disturbance, but most patients had neurologic deficits in addition to their aphasia. High correlations were found between the rCBF values within ischemic foci and WAIS subtests, as well as Token Test and word fluency tests. The correlation coefficients calculated between hemispheric flow and the psychological data indicated, in many instances, the same dependency, but did not attain the high statistical significance obtained with the regional values. The results show dependencies of several aspects of mental function upon cerebral perfusion and provide information for possible mechanisms responsible for the disturbance of nonverbal intelligence in aphasics.     

The nature of the phonological disorder in conduction aphasia

Sequences of attempts to name pictured objects were used to examine phonological dysfunction in three diagnostic subgroups of aphasia. A prevalence of "phonologically-oriented sequences" (i.e., those sequences that contained only attempts with a phonological resemblance to the target word) was found to be a diagnostic criterion for conduction aphasia. When compared to a group of Broca's (n = 7) and Wernicke's (n = 5) aphasics, all the conduction aphasics (n = 6) produced proportionately more of such phonologically-oriented sequences on a picture naming test. An examination of the phonologically-oriented sequences produced by the conduction aphasics indicates that speech production in conduction aphasia involves dysfunction at an early stage of sound-encoding. The theoretical implications of this view are discussed.     

Development of comprehension of sentences with “because” or “if”

The comprehension of sentences with “because” or “if” was investigated in children aged 2;9–11;11. Imitation, comprehension (choosing one of two picture sequences to go with a sentence), recognition (judging sentences with connective or structure differences as heard before or not), and synonymy (judging equivalence of meaning in sentences with different connectives or structures) tasks were administered, along with logical ordering, reversibility, and classification tasks. Above-chance responding in the comprehension task occurred by age 8, and in recognition and synonymy by age 10. Cognitive performance predicted 28.4% of the variance in the linguistic scores and cognitive success was concurrent with or preceded linguistic success. Comprehension of “because” and “if” appears to develop gradually, and is related to the development of certain operative rules.     

Does long term use of piracetam improve speech disturbances due to ischemic cerebrovascular diseases?

Aphasia causes significant disability and handicap among stroke survivors. Language therapy is recommended for aphasic patients, but not always available. Piracetam, an old drug with novel properties, has been shown to have mild beneficial effects on post-stroke aphasia. In the current study, we investigated the effects of 6 months treatment with piracetam on aphasia following stroke. Thirty patients with first-ever ischemic strokes and related aphasia were enrolled in the study. The scores for the National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), modified Rankin Scale (mRS), and Gülhane Aphasia Test were recorded. The patients were scheduled randomly to receive either 4.8 g piracetam daily or placebo treatment for 6 months. At the end of 24 weeks, clinical assessments and aphasia tests were repeated. The level of improvement in the clinical parameters and aphasia scores was compared between the two groups. All patients had large lesions and severe aphasia. No significant difference was observed between the piracetam and placebo groups regarding the improvements in the NIHSS, BI and mRS scores at the end of the treatment. The improvements observed in spontaneous speech, reading fluency, auditory comprehension, reading comprehension, repetition, and naming were not significantly different in the piracetam and placebo groups, the difference reached significance only for auditory comprehension in favor of piracetam at the end of the treatment. Piracetam is well-tolerated in patients with post-stroke aphasia. Piracetam taken orally in a daily dose of 4.8 g for 6 months has no clear beneficial effect on post-stroke language disorders.     

Comprehension of sentence structure in anomic and conduction aphasia

Picture-pointing auditory and reading comprehension tests were administered to anomic and conduction aphasics. Subjects responded to active sentences of the present progressive form. The possible errors which a subject could make on these experimental tasks included failure to correctly interpret noun order, number, or lexical meaning. Both groups made significantly more correct responses than error responses. Of their error responses, noun-order errors significantly exceeded number and lexical errors for which no differences were observed. When compared with results previously obtained for agrammatic Broca's aphasics, no differences in the pattern of errors were identified. These results are discussed relative to current theories of syntactic processing and for the mechanisms which account for these syntactic comprehension deficits following aphasia.     

The recovery processes of two English-Japanese bilingual aphasics

The recovery processes of two English-Japanese bilingual aphasics, one with Broca's aphasia and the other with Wernicke's aphasia, were investigated with special emphasis on the effect of language therapy. The degree of impairment initially manifested in English and Japanese was almost equivalent in each case, the pattern of impairment corresponding to the respective types of aphasia. In both cases, systematic, controlled language therapy was conducted. Analysis of the recovery courses revealed that language therapy was one decisive variable in the relative degree of recovery of a bilingual aphasic's two languages. The type of aphasia appeared to exert a crucial influence on the relative recovery rate of different modalities.     

A study of repetition in aphasic patients

The ability of the aphasic patient to repeat a message is a capacity of considerable diagnostic value. While it is well known that certain aphasic groups (e.g., transcortical aphasics) repeat better than other groups (e.g., conduction aphasics), possible qualitative differences among the groups have not been subjected to analysis. To secure information on repetition profiles in various aphasic subgroups, a test consisting of 11 types of items, presented under conditions of both immediate and delayed recall, was administered to eight groups of aphasic patients. The results documented a significant difference across aphasic groups, one related to site of lesion but not to severity of comprehension defect. Performance proved to be a joint product of the length and the meaningfulness of the stimulus items. The delayed condition aided Broca's aphasics and impeded anomic aphasics; in addition, nonsense syllables proved to be easier on immediate recall, while meaningful stimuli, particularly those which were number related, were relatively easier on delayed recall. Finally, sound errors were more likely to be made by Broca's and “mixed anterior” aphasics, while meaning errors were particularly prominent among conduction aphasics. These results are discussed in terms of the mechanisms which may mediate repetition in aphasic patients.     

Automatic and volitional semantic processing in aphasia.

The present study investigated the status of semantic information in aphasia by comparing the performances of aphasic and nonaphasic subjects on two tasks: an automatic semantic facilitation task and a volitional task of relatedness judgment. Both the aphasic and nonaphasic groups evidenced a semantic facilitation effect, in an on-line task of semantic processing. However, those aphasics with severe comprehension and naming disturbances (termed low comprehension aphasics) demonstrated considerable difficulty in judging the relatedness between a pictured object and members of that object's semantic field, the severity of the impairment being greater for those pictures that the low comprehension aphasics were unable to name. The pattern of results can best be explained by supposing the structural integrity of the store of semantic information in aphasia, and in particular in low comprehension aphasia: information that is retrieved and manipulated in judgment-mediated tasks with considerable difficulty.     

Picture-naming in aphasia

The distribution of picture-naming errors for Broca's aphasics (n = 9), Wernicke's aphasics (n = 9), conduction aphasics (n = 9), frontal anomics (n = 7), and posterior anomics (n = 9) was examined to determine the diagnostic power of error types in picture-naming. Negated responses were associated with Broca's aphasia, whole-part errors ("hose" for nozzle) were associated with frontal anomia, and poor phonemic cuing was associated with Wernicke's aphasia. In addition, the relative distribution of the three most prominent naming errors-phonemic errors, semantic errors, and multiword circumlocutions-tended to distinguish the two anomic subgroups from the other aphasia subgroups. Anomic aphasics produced the fewest phonemic errors and the most multiword circumlocutions; this pattern suggests minimal word-production difficulty in anomic aphasia relative to the other aphasia syndromes. Despite such group differences, the overall picture indicates that there is considerable similarity among aphasia syndromes in terms of picture-naming behavior.     

Syntactic component in language responsible cognitive structure: Neurological evidence

From the results of a broad ranging comprehension test, a hierarchy of difficulty emerged that is shared by the two groups of aphasics (Broca's and Wernicke's aphasics) and by the control group of normal subjects. The parallelism has been interpreted as a confirmation of the hypothesis that syntactic competence is not inaccessible either in Wernicke's or in Broca's aphasia. The Minimal Distance Principle, as a relevant recognition principle, has been studied, and although not confirmed by the scores has been brought to the fore both by the correlations between the variables under study and by the correlations with the concomitant variables of age and level of education.     

Phonological processing in Broca's aphasics

Phonological processing was investigated in nine Broca's aphasics. A receptive phonological task examined knowledge of phonotactic rules. Three lists of “word” pairs, phoneme sequences, were constructed such that one member was possible in English and the other was not. The lists varied in distance from English or phonemic structure (CCVC vs. CCVCC). Following auditory presentation, the aphasic was required to indicate which of the two “words” was possible in English. The productive task was an articulation test for monosyllabic and polysyllabic words. The high positive correlation between receptive and productive scores suggested that, rather than motor speech sequencing problems being exclusively involved, more general phonological-articulatory processes were disrupted. Several hypotheses were advanced to describe the nature of this disruption.     

Aphasics' sensitivity to contextual appropriateness conditions for pragmatic indicators

Twenty normal and twenty aphasic subjects were tested for their understanding of implicit meanings of the French adverbs même (even), aussi (also), and surtout (mainly). Their sensitivity to the contextual appropriateness conditions of such items was analyzed in a multiple-choice paradigm requiring them to select from three figures the one which was best described by a sentence like "Show me the figure that is même (aussi, surtout) red." A global quantitative comparison indicates that aphasics' performance was inferior to that of the normal controls. Yet, the analysis of individual responses allowed the identification of three different subgroups of aphasics: the first produced responses identical to the normals' responses; the second seemed to ignore the adverb and systematically selected the figure with the highest amount of the asserted color; and the third produced responses identical to the normals' responses for surtout but had difficulties with même or aussi. As concerns the relationship between aphasics' performance and their scores on literal language comprehension tests, the data favor the dissociation between literal and pragmatic factors in comprehension. Finally, no clear relationship was observed between aphasia type and aphasics' performance, although three points are noted in the discussion: (1) all the conduction aphasics performed like normals, (2) among the Broca's aphasics, the one with the clearest agrammatic verbal output produced responses similar to those of the normals, and (3) there was no anomic patient in the second subgroup.