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A meta-analysis of 31 studies with 1,791 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of focal cortical lesions. Relative to healthy controls, participants with focal frontal injuries had large and comparable deficits on phonemic (r = .52) and semantic (r = .54) fluency. For frontal but not nonfrontal patients, phonemic fluency deficits qualified as differential deficits when compared with IQ and psychomotor speed; phonemic fluency was also more strongly and more specifically related to the presence of frontal lesions than the Wisconsin Card Sorting Test scores. In contrast, temporal damage was associated with a lesser deficit on phonemic fluency (r = .44) but a larger deficit on semantic fluency (r = .61).

Two underlying components of verbal fluency tasks have been identified as clustering (the ability to generate successive words within a sub-category) and switching (the ability to shift from one sub-category to another). Selective impairment of switching ability occurs in patients with frontostriatal pathology, whilst clustering ability is compromised with temporal lobe dysfunction. Letter fluency tasks have been shown to be especially sensitive to frontostriatal deficits, whereas, category fluency tasks tend to be compromised by temporal lobe pathology. This study examined two types of verbal fluency task (letter fluency and category fluency) using two levels of analysis (phonemic and semantic) for clustering and switching measures. The performance of 21 frontostriatally compromised Huntington's disease (HD) patients was followed over an average of 3.5 annual follow-up visits. HD patients showed a significant reduction of correctly generated words over time, together with a significant increase in word repetitions. Phonemic switching decreased significantly over time for both letter and category fluency. Semantic switching, however, remained stable over time for both verbal fluency tasks. Clustering (both semantic and phonemic) likewise remained stable and did not vary longitudinally for either letter or category fluency. Hence, phonemic switching alone drove verbal fluency performance and this selective impairment can be explained by the progressive involvement of frontostriatal circuitry in the natural progression of HD.

It has long been recognized that a basic dimension to the lexical organization of the brain is semantic, and some brain mapping studies have indicated that the brain fields are distinctly different from some grammatical classes. Findings from the present investigation showed consistent relationships between 29 aphasic adults' performances on tasks involving graphic and gestural skills and those involving sequential recall of spoken words from different word categories. Each adult received the Porch Index of Communication Abilities which relies upon the physical manipulation of objects to assess verbal, gestural, and graphic abilities. Scores on a test requiring recall of word strings of nouns, verbs, adverbs, adjectives, or prepositions were used to predict the subscale scores from the Graphic and Gestural factors of the index. Recall scores for verb and preposition were predictive of the aphasic subjects' performances on the Graphic subscale, and noun and preposition scores were predictors of subjects' scores on the Gestural subscale. The results are related to other research showing that verb and preposition skills are predictive of fine motor abilities of children with communication disorders and brain-mapping studies. Some discussion centers on possible overlapping functions of brain activity involving word categories, language, and fine motor skills.

A longitudinal case study of a patient with a progressive loss of meaning of objects with preserved phonology and syntax is presented. Repeated measures of language, praxis, visual cognition, and semantic processing were carried out. The patient still has preserved conversational speech, social skills, and orientation in her 8th year of her illness, but shows severe anomia and comprehension deficit in all modalities of stimulus presentation. In addition to standardized tests of language, cognition, and memory, specific experiments of categorization, modalities of word access, item consistency, category specificity, and definition of words were carried out. Results indicate a frequency dependent loss of meaning that was consistent in all modalities and throughout all object categories. However, the relative preservation of visual categorization of all categories tested and the language based categorization of animals suggested some fractionation of semantic memory. Relative preservation of autobiographical and personal memories versus semantic memory was a striking observation. Evidence for selective impairment of central semantic processing was obtained from experiments indicating item consistency of loss and the lack of semantic cuing. Neuroimaging evidence of left temporal lobe atrophy and the classical picture is compatible with similar cases published under the term semantic dementia or "transcortical sensory aphasia with visual agnosia" and suggest the diagnosis of Pick's disease.

To account for cross-linguistic differences in agrammatism, Bates and her colleagues have employed the Competition Model, proposing that the cue validity and cue costs of a grammatical morpheme in a particular language will directly affect how agrammatism is manifested. Using Goodglass et al.'s (1993) Morphosyntax Battery in English and a translated version in Spanish, we analyzed the use of equivalent grammatical structures in production and comprehension by agrammatic speakers of the two languages. Wilcoxon signed-rank tests revealed that the relative order of difficulty in both production and comprehension of various grammatical morphemes was the same for both Spanish- and English-speaking agrammatic patients, with two exceptions (1) the Spanish-speaking agrammatics were relatively better at producing subject-verb agreement, and (2) the Spanish speakers were significantly worse at comprehending both active and passive voice sentences. The Competition Model can explain the performance differences regarding subject-verb agreement and comprehension of active voice sentences, but it cannot account for the differences seen in comprehending passive voice sentences.

Whether multiple conscious efforts at word search bring a subject closer to an elusive word and to eventual successful retrieval remains a subject of debate. Previous work with normal participants has shown that multiple attempts eventuating in correct retrieval are not usually associated with a systematic progression toward target word phonology in the intervening attempts. In this study we analyzed the naming errors produced by 30 aphasic patients who had received the Boston Naming Test. The analyses were designed to elucidate the characteristics of responses that led to eventual success. Our data showed that among aphasics, as with normal subjects, the presence of target-initial phonology in the subject's first response was the most important predictor of correct retrieval. Moreover, progression towards target phonology in the course of multiple attempts was unrelated to eventual correct retrieval.

Two patients with nonfluent progressive aphasia, who have been studied longitudinally, are contrasted with a group of 5 patients with fluent progressive aphasia or semantic dementia. The most prominent feature of the nonfluent syndrome is the severe distortion of speech output with phonological errors and agrammatic sentence structure. This contrasts with the fluent, well articulated and syntactically correct, but empty, anomic speech found in semantic dementia. Performance on tests of comprehension separates the patient groups: The nonfluent patients show normal single-word comprehension, but marked impairment on tests of syntactic comprehension, while those with semantic dementia demonstrate the opposite pattern. Category fluency is severely defective in semantic dementia, but initial letter-based fluency is more impaired in the nonfluent syndrome. Performance on nonverbally mediated tests of semantic knowledge is impaired in semantic dementia only. The 2 forms of progressive aphasia have in common the sparing of perceptual and visuospatial skills, nonverbal problem solving abilities, and day-to-day (episodic) memory. Neuroradiological investigations have shown marked selective and striking inferolateral left temporal lobe atrophy in all 5 patients with semantic dementia. The changes in nonfluent progressive aphasia appear to be less focal and involve left perisylvian structures more diffusely. These 2 forms of progressive aphasia are, we argue, distinct in their manifestations.

The effect of mild aphasia (n = 9), as a result of subarachnoid haemorrhage (SAH), was evaluated against one matched (sex, age, and education) control group suffering from SAH of unknown origin without aphasia, and against one matched healthy control group. According to aphasia testing (Reinvang & Engvik, 1980), criteria for a classical diagnosis were not met. Therefore, the patients were characterized as mild aphasics: They generally displayed intact audo-verbal comprehension and repetition abilities, and they demonstrated a fluent, spontaneous speech. However, they showed phonemic and semantic paraphasias, with self-corrections; a few patients displayed alexia and agraphia. Memory performance of these three groups was evaluated by a neuropsychological test battery, designed to tap various components of verbal memory function. From the results it was concluded that: (a) Short-term memory is impaired, as regards the phonological loop and the central executive in working memory, whereas maintenance rehearsal is unaffected, given that the demands on phonological coding is minimized, (b) long-term memory is also generally impaired, whereas long-term learning and forgetting by means of subject-performed tasks proceeds within a normal range. Impairments were hypothesized to reflect less efficient central executive functions of working memory, involving generation of less appropriate semantic codes and phonological representations, (c) mildly aphasic patients are not subjectively aware of their own memory deficits, and (d) aphasia classification by means of standard procedures do not sufficiently characterize the nature of a mildy aphasic patient's memory problems.

This study investigates French-speaking aphasics' sensitivity to gender (of human nouns) and number marking in a sentential context. Using a forced picture choice task, we tested sentences in which grammatical marking surfaced either on a function word or on a content word, within or outside a noun phrase (NP) whose gender or number was required to be identified. Ten fluent and 10 nonfluent aphasics together with 20 adults without neurological history were tested. Results showed that neither group of aphasics presented an across-the-board deficit. Nonfluent patients were strongly impaired when marking surfaced on a content word outside NP (verbs and adjectives), but their sensitivity to grammatical marking was relatively well preserved in the within NP condition (determiners and nouns) and for function words in the outside NP condition (the copula). Fluent patients showed a specific impairment in dealing with semantic gender (as opposed to number information); and their difficulty was exacerbated when the information conveyed by the suffix of a content word must be integrated into an higher order semantic representation, as in the outside NP condition (adjectives). These results are consistent with the view that for both nonfluent and fluent aphasics, the functional locus of their impairment lies on a reduction in the computational resources available to the language processor, which is more severe in the former than in the latter group.

The Aachen Aphasia Bedside Test (AABT) has been developed in order to examine aphasic patients within the first 4 to 6 weeks after onset of illness. The psychometric properties of the AABT were established by repeated examination of 82 acute stroke patients, ratings by 20 raters on the basis of 10 videotapes, repeated examination of 28 chronic aphasics three times with an interval of 2 days, and parallel examination of 47 chronic aphasic patients with the AABT and the Aachen Aphasia Test (AAT), administered on the same day. Objectivity, reliability and validity of the AABT were highly rated, indicating its usefulness in acute stroke cases. Data on the 82 acute stroke patients showed that an initial prognosis can be made as early as the fourth day after the stroke.

A group of Broca's aphasics (BA), Wernicke's aphasics (WA) and normal controls participated in a CLOZE experiment which required the oral production of various types of free and bound morphemes. Results provided support for the hypothesis that BA and WA share the same underlying impairment in the production of grammatical morphology. The relative difficulty of the various free and bound morpheme types was the same for BA and WA. This appeared to be the case not only in an analysis of the number of errors but also in an analysis of response times. The same analyses furthermore revealed no significant differences in the absolute levels of performance of BA and WA. Finally, it was found that BA and WA show the same relative contribution of within- and across-category substitutions of free morphemes. For bound morphemes, there was a slight difference between BA and WA, in that BA exclusively produced within-category substitutions while WA also produced some across-category substitutions.

We assessed the usefulness of the Western Aphasia Battery for distinguishing the language disturbances caused by Alzheimer dementia (AD) from those caused by stroke. Using discriminant function analyses, the multiple variable "aphasia quotient--reading quotient--writing quotient" classified 29 (72.5%) of the 40 patients correctly. These 29 patients included 8 of 10 patients with left hemisphere infarction and fluent aphasia; 6 of 10 with AD; 5 of 10 patients with right hemisphere infarction; and all 10 of the neurologically normal control subjects. The patients with AD and those with right hemisphere stroke were the most difficult to classify using the aphasia battery.

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.

An assessment of the current memory status of patients referred for speech therapy is rarely provided, but may be useful in indicating whether there is memory loss in addition to language deficits. Failure to progress during treatment could be due to failure to remember the content of the previous sessions. Most existing memory tests are unsuitable for assessing subjects with dysphasia. For that reason we sought to modify the Rivermead Behavioural Memory Test (RBMT: Wilson, Cockburn & Baddeley, 1985), which was developed to measure the existence and extent of everyday memory problems and which contains both verbally and non-verbally mediated items. The study described here, based on a sample of 176 brain-injured patients, showed that a mild to moderate language deficit did impair performance on the RBMT. The influence was found to be limited to a subset of verbal memory items. A shortened version of the test was developed and shown to be sensitive to memory deficits and insensitive to the effects of dysphasia. Revised norms for this version of the test are provided. These should enable an estimate to be made of the presence and magnitude of memory deficits in dysphasic patients, allowing treatment to be optimized.

When an aphasic is unable to name an object, giving the patient the opening sounds of the target name will often trigger the correct response. Eighteen aphasic subjects were tested using a gating paradigm to compare word onset durations necessary to elicit correct names after an initial naming failure with those necessary for recognizing the same words when spoken in isolation with no picture present. Prerecognition errors were also examined. Results suggested that the facilitation of naming found when examiners supply word-onset sound cues may be due in part to a two-stage process consisting of stem-completion followed by matching the picture with the potential name as generated.

Ten fluent and ten nonfluent aphasics participated in this study. Their ability to comprehend before and after clauses which mirrored the order of occurrence and those which did not mirror the order of events was investigated. Results indicate that type of aphasia was not a significant variable related to comprehension but that sentence type was a significant variable. Aphasics' comprehend before clauses better than after clauses. Nonfluent aphasics were able to comprehend those temporal clauses that mirror the order of occurrence better than those that do not. Order of mention was not a significant factor related to comprehension in the fluent group.

Syntactic complexity was systematically manipulated in sentence and discourse comprehension tasks. Aphasic patients, but not normal controls, showed effects of syntactic structure in the sentence comprehension task. Neither aphasic nor control subjects showed significant differences between the comprehension of syntactically simple and complex stories. This pattern confirms the clinical impression that some discourses can be understood by patients who cannot utilize syntactically based sentence comprehension mechanisms.

The repetition performance of a patient (S.T.) with transcortical sensory aphasia is examined in four experiments with particular emphasis on the STM capacities underlying her performance. S.T.'s repetition of word strings exceeding her span (two words) is characterized by good recall of the final items and a strong tendency to lose the initial items in the input string. This pattern contrasts with the serial position effects observed in a phonologically based STM impairment, and it is suggested that a lexical-semantic impairment, also evident in S.T.'s naming and lexical comprehension, contributes to her inability to retain the primacy portions of the input string. Lexical effects obtained in her reproduction of words and nonwords, as well as word strings (Experiments 1 and 2), indicate that under conditions of impaired semantics S.T. is relying on lexical phonological information to repeat. Priming by repeated exposure (Experiment 3) failed to improve her repetition performance, indicating that access to lexical information is brief and dependent on recent phonological input. In Experiment 4, the role of syntactic structure in S.T.'s sentence repetition was examined, and it was shown that syntactic structure affects the recall of order information, but not the number of items recalled. The repetition and verbal STM abilities of this patient, in light of her total language profile, are then evaluated in the context of a language-based view of verbal STM.

"Deep dysphasia" is the parallel in repetition to the reading impairment deep dyslexia. Our patient, S.M., showed part of speech, word/nonword, and concreteness effects in repetition, and he made semantic errors, but his oral reading was relatively spared. Further testing indicated that S.M. did not have difficulty perceiving spoken stimuli or deciding their lexical status, but he was deficient at semantically processing spoken words. Moreover, his phonemic memory was severely impaired. We argue that the routes for repetition (lexical and nonlexical) that function without semantic mediation were defective and that deficits in phonemic memory further diminished their effectiveness, since initial phonological encoding of spoken words was not available to guide the output stages of phonological processing. In addition, the semantically mediated route for repetition was unreliable because semantic processing was faulty and S.M. could not accurately label concepts.

A case study is reported of an aphasic patient, RB, who showed frequent form-related whole-word substitutions in oral naming, writing to dictation, and reading aloud. In both written language tasks, the abstractness of the targets influenced the number of formal errors. In oral naming, a high proportion of formal paraphasias was related to the intended words in both form and meaning. A comparison between targets and formal paraphasias indicated a high agreement both in word class, number of syllables, stress pattern, and in basic (stressed) vowels. The agreement in consonants (including word-initial consonants), however, was low. It is argued that RB's formal substitutions are not caused solely by errors of lexical selection but that semantic, lexical, and segmental factors contribute to the error outcome.

This paper discusses a recent article by Chapman and Ulatowska (1989, Brain and Language, 36, 651-658) on discourse analysis in aphasia. As such, the research in this area is interdisciplinary drawing from neuropsychology, as well as cognitive psychology, and, in part, aging. We illustrate problems that can arise when theoretical constructs and methodological considerations in this interdisciplinary approach are not rigorously observed. It is argued that definitive conclusions regarding the functional organization of the brain and discourse can be offered only when discourse analysis uses the state of the art from neuropsychology and cognitive psychology.

This study examined the repetition errors of three aphasic subgroups during a repetition task. A total of 95 subjects, including 32 conduction, 38 Broca's, and 25 Wernicke's aphasics, repeated phrases and sentences from the Repeating Phrases Subtest of the Boston Diagnostic Aphasia Examination. Conduction aphasics exhibited a greater number of phonemic attempts, word revisions, and word and phrase repetitions. Broca's aphasics demonstrated more phonemic errors and omissions. Finally, Wernicke's aphasics showed more unrelated words and jargon.

This study examines verb processing during on-line sentence comprehension in aphasia. We describe two experiments that explore whether a group of Broca's aphasics, who were agrammatic in comprehension as well as speech, a group of fluent aphasics, and a group of normal controls are sensitive to the argument structure arrangements of verbs. Subjects had to perform a complex secondary task both in the immediate vicinity of the verb and also at a point well past the verb while listening to sentences for meaning. Reaction times to this secondary task show that both normal controls and agrammatic Broca's aphasic subjects activate multiple argument structure possibilities for a verb in the vicinity of the verb, yet at a point downstream from the verb such effects disappear. These data suggest that the problems agrammatic subjects show with verbs in sentence comprehension, and the general lexical access deficit also recently claimed to be part of the agrammatics' problem, may not extend to the real-time processing of verbs and their arguments. Fluent aphasic subjects, on the other hand, do not show sensitivity to the argument structure properties of verbs, suggesting that these patients may have a semantic-like sentence processing deficit.

We report a patient who suffered from progressive aphasia for nine years, before developing mild behavioural disturbances. Sequential computed tomography (CT) scanning and magnetic resonance (MRI) imaging showed progressive bilateral temporal atrophy. The case is thought to be a temporal form of Pick's disease, in which isolated progressive aphasia was the only symptom over many years.

This study investigated the effects of two types of cues (semantic and phonemic) and two grammatic classes (noun and verb) on cueing responsiveness. Subjects consisted of 10 Broca's, 10 Wernicke's, 8 conduction, and 8 anomic aphasics. Cues were administered following failure to name on confrontation. Responsiveness to the two types of cues was dependent on aphasic type and grammatic class. Broca's and conduction aphasics responded better to phonemic cueing, while anomic aphasics were more responsive to semantic cueing. With regard to grammatic class, aphasics responded better to phonemic cueing on nouns; however, no significant difference between types of cues was demonstrated on verbs. Neuropsychological implications for the cueing and naming processes are discussed.

The recovery of word-emission ability by Japanese aphasics was examined quantitatively. The scores on a word-emission task were obtained in a series of language tests for aphasia. 17 aphasics were asked to utter names of animals, giving as many as possible within a minute. The task was repeated four times at intervals of 104.1 days on the average, ranging from 27 to 271 days. The score on the word-emission task was estimated by fitting a growth curve to scores on the former three tests. Modified exponential, logistic, and Gompertz curves were used for estimation. All estimated scores by three growth curves were larger than the observed scores. The modified exponential curve which does not have an inflection point produced the most remarkable error. Between two curves which have an inflection point the logistic curve produced less error than the Gompertz curve. The difference in error of estimation was due to the difference in the saturation level of the two curves.

Broca's aphasics and normal controls were tested to determine relative sparing and impairment of word order, grammatical morphology, and semantic information in a sentence interpretation task. Patients were native speakers of English, German, or Italian, languages that vary drastically in the "cue validity" or information value of these three sources of information. Word order was selectively spared while grammatical morphology was selectively impaired in all three languages. Nevertheless, language-specific patterns of sentence interpretation remained in Broca's aphasics, even within the impaired morphological component, supporting an interpretation in terms of "accessing" rather than a "loss." Testing with Wernicke's aphasics, anomics, and some additional age-matched controls suggested that the selective vulnerability of morphology is not specific to agrammatic patients, at least in this paradigm.

A new summary score, the Language Quotient (LQ), which reflects auditory comprehension, oral expression, reading, and writing performance, is described for the Western Aphasia Battery (WAB). As a summary score of the severity of the language impairment, the LQ is useful to clinicians both for assessment purposes and as an outcome measure to evaluate progress in aphasic patients as treatment proceeds. Reliability and validity of the LQ meet established standards for test construction.

Methods for the analysis of a single subject's test profile(s) proposed by Huber (1973) are applied to the Aachen Aphasia Test (AAT). The procedures are based on the classical test theory model (Lord & Novick, 1968) and are suited for any (achievement) test with standard norms from a large standardization sample and satisfactory reliability estimates. Two test profiles of a Wernicke's aphasic, obtained before and after a 3-month period of speech therapy, are analyzed using inferential comparisons between (groups of) subtest scores on one test application and between two test administrations for single (groups of) subtests. For each of these comparisons, the two aspects of (i) significant (reliable) differences in performance beyond measurement error and (ii) the diagnostic validity of that difference in the reference population of aphasic patients are assessed. Significant differences between standardized subtest scores and a remarkably better preserved reading and writing ability could be found for both test administrations using the multiple test procedure of Holm (1979). Comparison of both profiles revealed an overall increase in performance for each subtest as well as changes in level of performance relations between pairs of subtests.

The purpose of this study was to investigate the potential effect that color in visual stimuli may have on the confrontation naming ability of aphasic patients. A group of 11 nonfluent and fluent aphasic adults were administered identical black and white and colored versions of a naming test. Administration procedure for the tests required that a phonemic cue be given in the event of an incorrect response. The results revealed that the presence of color in the visual stimuli did not result in significantly improved naming performance in either group of subjects. Only the addition of the phonemic cue resulted in improved naming performance for both the nonfluent and fluent aphasic subjects. Further, no additional benefit was seen when color and cue were simultaneously presented.

The language profile of a group of 18 Alzheimer patients is documented and their performance on a standard aphasia test battery compared to a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. The Alzheimer patients scored significantly lower than the controls in the areas of verbal expression, auditory comprehension, repetition, reading, and writing. Articulation abilities were the same in each group. A language deficit was evident in all Alzheimer patients. The language disorder exhibited resembled a transcortical sensory aphasia. Syntax and phonology remained relatively intact but semantic abilities were impaired. The results support the inclusion of a language deficit as a diagnostic criterion of Alzheimer's disease.

Thirty-seven aphasic patients whose native language is Spanish were divided into four groups: (1) Broca's, (2) Wernicke's, (3) Conduction, and (4) Anomia. Phonological errors produced on repetition and object-naming tasks were analyzed in terms of type of transformation and degree of similarity between target and errors in terms of shared distinctive features. Segmental transformations were of the following types: (1) pure substitution, (2) pure addition, (3) deletion, (4) reduplicative addition (doublet creation)--anticipatory (right to left) or preservative (left to right), (5) reduplicative substitution (doublet creation)--anticipatory or perseverative, and (6) mutual exchanges. Pure substitutions were the most prevalent, exchanges, the least. Some error types were found to differentiate significantly between aphasic populations. We suggest that different mechanisms may underlie the same error type for different aphasic populations.

This study has two objectives: (1) to determine through the analysis of surface manifestations of anomia whether one or several anomic syndromes exist, (2) to identify the psycholinguistic process at fault in anomia with reference to M. F. Garrett's (1982, in A. Ellis (Ed.), Normality and pathology in cognitive functions, London/New York: Academic Press) language production model. Two naming tasks were administered to 24 moderate aphasics. Test A was a standard naming task, and test B was a similar task which included subtests designed to indicate which level of representation was affected whenever patients did not name the target word. The subtests required, respectively, the identification of (a) a conceptual property, (b) two semantic attributes, (c) the first and (d) last syllable of the target word, and (e) the target word itself. Descriptive statistics yielded three groups of subjects different in terms of surface anomic manifestations, yet unrelated to clinical type of aphasia. Moreover, no significant differences between groups emerged on the subtests. All groups showed a good performance on the conceptual and the semantic subtests, suggesting preservation of high-level cognitive and semantic processes. In contrast, subjects evidenced poorer performances in syllabic identification, indicating a disruption of lower level mechanisms which are assumed to retrieve and process formal lexical representations. Results support the view that aphasic anomia originates from a difficulty in accessing the formal lexical representation and not from a semantic problem.

The linguistic performance of 120 aphasic patients of the four standard syndromes assessed by the Aachen Aphasia Test (AAT) is analyzed by a nonmetric (ordinal) multidimensional scaling procedure (Smallest Space Analysis, SSA1). The linguistic structure of the test items is characterized within the framework of L. Guttman's facet theory. Three systematic components (facets) are discerned: linguistic modality, unit, and regularity. Properties of the facets as well as their relations are assessed and tested empirically by analyzing the interrelations among different items or sets of items. The spatial configurations obtained by the scaling procedure fit only partially the expectations derived from the facet-theory model. The modality facet was found to have a strong overriding influence on the aphasic test performance. The facets unit and regularity were only found for the most rigorously designed subtests. Written Language and Comprehension. The results suggest the introduction of a new combined facet linguistic complexity which reflects the dependency of the facets regularity and unit.

The supermarket verbal fluency test of the Dementia Rating Scale (DRS) was administered to 20 patients with mild Alzheimer's disease (Mi-DAT), 20 patients with moderately severe Alzheimer's disease (Mo-DAT), 20 patients with Huntington's disease (HD), and 40 normal control subjects. The findings confirmed previous reports that Mo-DAT patients retrieved fewer words per category of supermarket items sampled and had a greater propensity to generate category labels (superordinates) than did intact controls. Similar disruptions of the structure of semantic knowledge were also noted in the fluency performances of the Mi-DAT and HD patients. The Mi-DAT patients' tendency to generate few exemplars for each category sampled suggested that a significant disruption in the structure of semantic knowledge occurred even in the earliest stages of DAT. When the present fluency findings for the HD patients were considered with previous reports of linguistic changes in this disorder, it appeared that HD patients' deterioration in semantic knowledge involved associative changes rather than the bottom-up breakdown associated with DAT.