Demonstrating a wordlikeness effect on nonword repetition performance in a conduction aphasic patient

The purpose of this study was to identify the nature of the deficit for a conduction aphasic patient in order to evaluate two different theories of conduction aphasia. First, a conduction aphasic patient FS was tested on auditory word-pair discrimination, word-repetition, and picture-naming. The results of these tasks indicated that her deficit was likely to be post-lexical rather than perceptual or lexical. Next, we examined her repetition performance for two types of nonwords (high-wordlike and low-wordlike nonwords) to distinguish the two theories. FS exhibited a wordlikeness effect: she produced more correct moras and more correct combinations of moras for high-wordlike nonwords than low-wordlike nonwords. We conclude that she had difficulty in maintaining stable phonological representations of verbal materials in the output buffer.     

The classifier problem in Chinese aphasia

In recent years, research on the relationship between brain organization and language processing has benefited tremendously from cross-linguistic comparisons of language disorders among different types of aphasic patients. Results from these cross-linguistic studies have shown that the same aphasic syndromes often look very different from one language to another, suggesting that language-specific knowledge is largely preserved in Broca's and Wernicke's aphasics. In this paper, Chinese aphasic patients were examined with respect to their (in)ability to use classifiers in a noun phrase. The Chinese language, in addition to its lack of verb conjugation and an absence of noun declension, is exceptional in yet another respect: articles, numerals, and other such modifiers cannot directly precede their associated nouns, there has to be an intervening morpheme called a classifier. The appropriate usage of nominal classifiers is considered to be one of the most difficult aspects of Chinese grammar. Our examination of Chinese aphasic patients revealed two essential points. First, Chinese aphasic patients experience difficulty in the production of nominal classifiers, committing a significant number of errors of omission and/or substitution. Second, two different kinds of substitution errors are observed in Broca's and Wernicke's patients, and the detailed analysis of the difference demands a rethinking of the distinction between agrammatism and paragrammatism. The result adds to a growing body of evidence suggesting that grammar is impaired in fluent as well as nonfluent aphasia.     

Formal paraphasias: A single case study

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.     

The effects of grammatic class and cue type on cueing responsiveness in aphasia

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.     

Phonological transformations in Spanish-speaking aphasics

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 perseverative (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.     

Parameters for vowel substitutions in Broca''s aphasia

Most phonological investigations of aphasic speech have focused on consonants. In this study, the vowel substitutions of five English-speaking Broca's aphasics were investigated with respect to several major explanatory hypotheses. An important possible motivating factor for aphasic substitutions, phonological environment, is an unlikely origin for these errors, since most substitutions occur along the paradigmatic axis. Another prominent hypothesis, markedness, also has no predictive power for the data of this sample. However, an analysis of the five Chomsky and Halle (1968, (The Sound Pattern of English), New York: Harper and Row) vowel features indicates that the two features for vowel height are selectively impaired: There is a strong tendency for lower vowels to replace higher targets. Moreover, the substitution sounds tend to be close to their target sounds along the height axis. Four possible hypotheses are advanced to account for this consistent lowering tendency.     

Word order and finiteness in Dutch and English Broca's and Wernicke's aphasia

The effect of two linguistic factors in Broca's and Wernicke's aphasia was examined using Dutch and English subjects. Three tasks were used to test (1). the comprehension and (2). the construction of sentences, where verbs (in Dutch) and verb arguments (in Dutch and English) are in canonical versus non-canonical position; (3). the production of finite versus infinitive verbs. Proportions of errors as well as types of errors made by each aphasic group are similar on the sentence comprehension and sentence anagram tasks. On the verb production task the performance pattern is, again, the same, but the error types are different. The discussion focuses on how the similarities and differences across languages and across aphasia types may be interpreted with respect to the underlying deficit in Broca's and Wernicke's aphasia.     

Mimicking aphasic semantic errors in normal speech production: evidence from a novel experimental paradigm

Semantic errors are commonly found in semantic dementia (SD) and some forms of stroke aphasia and provide insights into semantic processing and speech production. Low error rates are found in standard picture naming tasks in normal controls. In order to increase error rates and thus provide an experimental model of aphasic performance, this study utilised a novel method- tempo picture naming. Experiment 1 showed that, compared to standard deadline naming tasks, participants made more errors on the tempo picture naming tasks. Further, RTs were longer and more errors were produced to living items than non-living items a pattern seen in both semantic dementia and semantically-impaired stroke aphasic patients. Experiment 2 showed that providing the initial phoneme as a cue enhanced performance whereas providing an incorrect phonemic cue further reduced performance. These results support the contention that the tempo picture naming paradigm reduces the time allowed for controlled semantic processing causing increased error rates. This experimental procedure would, therefore, appear to mimic the performance of aphasic patients with multi-modal semantic impairment that results from poor semantic control rather than the degradation of semantic representations observed in semantic dementia [Jefferies, E. A., & Lambon Ralph, M. A. (2006). Semantic impairment in stoke aphasia vs. semantic dementia: A case-series comparison. Brain, 129, 2132-2147]. Further implications for theories of semantic cognition and models of speech processing are discussed.     

Effect of typicality on online category verification of animate category exemplars in aphasia

Normal young, elderly, Broca's aphasic, and Wernicke's aphasic individuals participated in an online category verification task where primes were superordinate category labels while targets were either typical or atypical examples of animate categories or nonmembers belonging to inanimate categories. The reaction time to judge whether the target belonged to the preceding category label was measured. Results indicated that all four groups made significantly greater errors on atypical examples compared to typical examples. Young and elderly individuals, and Broca's aphasic patients performed similarly on the verification task; these groups demonstrated faster reaction times on typical examples than atypical examples. Wernicke's aphasic patients made the most errors on the task and were slowest to respond than any other participant group. Also, these participants were not significantly faster at accepting correct typical examples compared to correct atypical examples. The results from the four groups are discussed with relevance to prototype/family resemblance models of typicality.     

Action naming in anomic aphasic speakers: effects of instrumentality and name relation

Many studies reveal effects of verb type on verb retrieval, mainly in agrammatic aphasic speakers. In the current study, two factors that might play a role in action naming in anomic aphasic speakers were considered: the conceptual factor instrumentality and the lexical factor name relation to a noun. Instrumental verbs were shown to be better preserved than non-instrumental verbs in a group of anomic aphasic speakers but not in a group of Broca's aphasic speakers. Name relation to a noun improved the performance of the anomic aphasic speakers as well. Again, no effect was found in the group of Broca's aphasic speakers. Verbs with a name relation to a noun were better retrieved in action naming than verbs without a name relation. These findings are discussed in terms of the spreading activation theory of Dell. (Dell, G. S. (1986). A spreading activation theory of retrieval in sentence production. Psychological Review 93, 283-321.).     

Toward a functional classification of naming impairments

Three experiments involving confrontation naming and nonverbal classification tasks establish that impaired naming is relatively common in elderly cardiac patients, but that it can be distinguished functionally from aphasic dysnoia. The results suggest that while the aphasics' failures often reflected failure to retrieve the verbal labels of objects which were appropriately perceived, naming failures in cardiac patients were frequently precipitated by failure to éstablish the semantic identity of the target and were more sentitive to reductions in visual quality of the target picture.     

Phoneme frequency effects in jargon aphasia: a phonological investigation of nonword errors

This study investigates the nonwords produced by a jargon speaker, LT. Despite presenting with severe neologistic jargon, LT can produce discrete responses in picture naming tasks thus allowing the properties of his jargon to be investigated. This ability was exploited in two naming tasks. The first showed that LT's nonword errors are related to their targets despite being generally unrecognizable. This relatedness appears to be a general property of his errors suggesting that they are produced by lexical rather than nonlexical means. The second naming task used a set of stimuli controlled for their phonemic content. This allowed an investigation of target phonology at the level of individual phonemes. Nonword responses maintained the English distribution of consonants and showed a significant relationship to the target phonologies. A strong influence of phoneme frequency was identified. High frequency consonants showed a pattern of frequent but indiscriminate use. Low frequency consonants were realised less often but were largely restricted to target related contexts rarely appearing as error phonology. The findings are explained within a lexical activation network with the proposal that the resting levels of phoneme nodes are frequency sensitive. Predictions for the recovery of jargon aphasia and suggestions for future investigations are made.     

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.     

Written spelling deficit of Broca''s aphasics

The purpose of this study was to investigate the nature of the written spelling deficit manifested by Broca's aphasics. Four spelling tests were given to eight Broca's aphasic patients. Analysis of misspelling errors led the investigators to conclude that Broca's aphasics do not spell phonically, but rather adhere exclusively to a visual/orthographic strategy. Possible cognitive deficits underlying the spelling problem are identified. The written spelling deficit is related to other features of the syndrome of Broca's aphasia, and finally, speculations are offered concerning the neurological substrate of written spelling in Broca's aphasic patients.     

Lexical creativity during instances of word-finding difficulty: Broca's vs. Wernicke's aphasia

Lexical innovation--the creation of a word by combining existing morphemes in a novel way (e.g. "map ball" for "globe")--was evaluated as a method for circumventing word-finding difficulty in Broca's and Wernicke's aphasia. Aphasic groups were matched for naming performance and compared to a control group of normal adults matched for age and education. Lexical innovations were collected during the administration of a confrontation naming test, and were then analyzed in terms of the correctness of morpheme combination, semantic accuracy, novelty, and communicative effectiveness. An innovation was considered to be communicatively effective when its intended referent was understood by a naive judge. The lexical innovations of the two aphasic groups were diametrically opposed: as compared to both Broca's aphasics and normal adults, Wernicke's aphasics innovated significantly less often, and their innovations were significantly inferior in terms of: semantic precision, the proper construction of morpheme combination, and communicative effectiveness. This pattern suggests that lack of verbal fluency may be compatible with lexical creativity, while empty logorrheic speech may be an impediment to lexical creativity. Similarly, we conclude that the agrammatism of Broca's asphasia does not interfere with lexical innovation, while the paragrammatism of Wernicke's aphasia does interfere with lexical innovation, thus suggesting that paragrammatism affects morpheme combination at the word level as well as the sentence level.     

Word-finding abilities of three types of aphasic subjects

Word-finding difficulties are often observed among different types of aphasic patients. This investigation analyzed the word-finding abilities of 30 aphasic subjects (10 Broca's, 10 Wernicke's, and 10 anomic). Forty nouns counterbalanced according to word length and frequency of occurrence in English language usage were used as stimuli and presented through four modalities (oral expression, writing, auditory comprehension, and reading comprehension). It was expected that patterns of word finding abilities would help in the classification of the different types of aphasia. In addition, long words and less frequently occurring words in English language usage should prove more difficult in word-finding ability, regardless of modality. The results of this study found long words and less frequent words were more difficult for aphasic subjects. Among the modalities, long words were significantly harder than short words for the writing modality only. It was also found that semantic errors were the most common errors for all types of aphasic subjects. Broca's subjects produced significantly moreno response errors in oral expression; Wernicke's subjects produced significantly more semantic and phonemic errors in reading comprehension; and, Wernicke's subjects produced significantly more unrelated errors in both oral expression and reading comprehension. Clinical implications were also discussed.The present study was based on a doctoral dissertation completed at the City University of New York in partial fulfillment of the requirements of the doctoral degree in Speech and Hearing Sciences by the first author under the direction of the second author. The authors wish to thank Dr. Louis J. Gerstman for his assistance with the statistical analysis of this research and Dr. Robert Goldfarb for all his helpful suggestions and editorial comments.     

Enhancement of naming in nonfluent aphasia through gesture

In a number of studies that have examined the gestural disturbance in aphasia and the utility of gestural interventions in aphasia therapy, a variable degree of facilitation of verbalization during gestural activity has been reported. The present study examined the effect of different unilateral gestural movements on simultaneous oral-verbal expression, specifically naming to confrontation. It was hypothesized that activation of the phylogenetically older proximal motor system of the hemiplegic right arm in the execution of a communicative but nonrepresentational pointing gesture would have a facilitatory effect on naming ability. Twenty-four aphasic patients, representing five aphasic subtypes, including Broca's, Transcortical Motor, Anomic, Global, and Wernicke's aphasics were assessed under three gesture/naming conditions. The findings indicated that gestures produced through activation of the proximal (shoulder) musculature of the right paralytic limb differentially facilitated naming performance in the nonfluent subgroup, but not in the Wernicke's aphasics. These findings may be explained on the view that functional activation of the archaic proximal motor system of the hemiplegic limb, in the execution of a communicative gesture, permits access to preliminary stages in the formative process of the anterior action microgeny, which ultimately emerges in vocal articulation.