The processing of compounds in bilingual aphasia: A multiple‐case study

Background: While converging evidence has led to the view that people with aphasia exploit compositional procedures when producing compound words, the issue of what compound‐internal characteristics are at play during these procedures is still under debate. It has been argued that constituent position and/or morphosyntactic prominence, i.e., being the head constituent of a compound, may influence the manner in which compounds are accessed. However, findings obtained from patient performances are thus far inconclusive, because positional and headedness effects are frequently confounded in a language.

Aims: In order to disentangle position‐in‐the‐string and headedness effects in compound production in aphasia, the main objective of this study is to investigate the performance of bilingual patients speaking languages in which these effects can be teased apart. Our secondary goal is to probe the roles of grammatical category (adjectives vs nouns) and of between‐language phonological similarity, as both these factors have been demonstrated to influence compound processing.

Methods & Procedures: Three English–French bilingual persons with aphasia participated in the study. Three experimental tasks, reading, repetition, and translation of isolated compound words, were administrated in each language. We contrasted French and English compounds that differ in the position of the head constituent: left for French and right for English.

Outcomes & Results: Two participants showed a similar pattern—a significantly reduced number of errors for the head (or first) constituent as compared to the non‐head (or second) constituent in French and an equivalent number of errors for both constituents in English—pointing to the cumulative effects of headedness and first‐position‐in‐the‐string in French, and to the mutual cancelling out of these effects in English. The third participant exhibited a non‐head constituent advantage in both languages, indicating that semantic modification of the head constituent by the non‐head constituent plays a prominent role in her accessing procedures. For all three participants phonological similarity influenced production, while grammatical category did not.

Conclusions: Our results reveal that headedness and position interact in the processing of compounds. They also demonstrate that compound constituents are processed asymmetrically across and within languages, thus confirming that people with aphasia are sensitive to compound‐internal structure. Moreover, they show that patients rely on varying structural information when accessing compounds.     

Cortical and fibre tract interrelations in conduction aphasia

Background: The syndrome of conduction aphasia is an umbrella term to label clinically heterogeneous language disorders that all include a deficit of repetition due to impaired immediate memory or, in some patients, impaired speech production. The present article reviews the currently available literature on conduction aphasia. It covers aspects of the history of conduction aphasia as a fascicular disconnection syndrome and the objections to this view and discusses the proposed subtypes of this syndrome and the underlying cortical and white matter lesions.

Aims: The primary objectives of this article are to critically review the influence of historical concepts on recent approaches to optimise existing theoretical synergies. In addition, the article seeks to advance our understanding of the first steps of verbal auditory processing in individuals with normal and impaired language skills.

Main Contribution: We present first indications for an involvement of the left hemisphere in both short- and long-term integration of auditory information derived by examining patients with (conduction) aphasia.

Conclusions: Conduction aphasia may result from left hemisphere cortical lesions or from a disconnection of critical bundles of axons (fibre tract). The exact course of the fibre tract connections and the cortical regions involved in conduction aphasia remains controversial.     

Chance in agrammatic sentence comprehension: What does it really mean? Evidence from eye movements of German agrammatic aphasic patients

Background: In addition to the canonical subject-verb-object (SVO) word order, German also allows for non-canonical order (OVS), and the case-marking system supports thematic role interpretation. Previous eye-tracking studies (Kamide et al., 2003 Kamide, Y., Scheepers, C. and Altmann, G. M. 2003. Integration of syntactic and semantic information in predictive processing: Cross-linguistic evidence from German and English. Journal of Psycholinguistics Research, 32: 37–54. doi: 10.1023/A:1021933015362 [Google Scholar]; Knoeferle, 2007 Knoeferle, P. 2007. “Comparing the time-course of processing initially ambiguous and unambiguous German SVO/OVS sentences in depicted events”. In Eye movement research. A window on mind and brain, Edited by: van Gompel, R., Fischer, M., Murray, W. and Hill, R. 517–531. Oxford, , UK/Amsterdam: Elsevier.  [Google Scholar]) have shown that unambiguous case information in non-canonical sentences is processed incrementally. For individuals with agrammatic aphasia, comprehension of non-canonical sentences is at chance level (Burchert et al., 2003 Burchert, F., De Bleser, R. and Sonntag, K. 2003. Does morphology make the difference? Agrammatic sentence comprehension in German. Brain and Language, 87: 323–342. doi: 10.1016/S0093-934X(03)00132-9[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). The trace deletion hypothesis (Grodzinsky 1995 Grodzinsky, Y. 1995. A restrictive theory of agrammatic comprehension. Brain and Language, 50: 27–51. doi: 10.1006/brln.1995.1039[Crossref], [PubMed], [Web of Science ®] , [Google Scholar], 2000 Grodzinsky, Y. 2000. The neurology of syntax: Language use without Broca's area. Behavioral and Brain Sciences, 23: 1–71. doi: 10.1017/S0140525X00002399[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) claims that this is due to structural impairments in syntactic representations, which force the individual with aphasia (IWA) to apply a guessing strategy. However, recent studies investigating online sentence processing in aphasia (Caplan et al., 2007 Caplan, D., Waters, G., DeDe, G., Michaud, J. and Reddy, A. 2007. A study of syntactic processing in aphasia I: Behavioral (psycholinguistic) aspects. Brain and Language, 101: 103–150. doi: 10.1016/j.bandl.2006.06.225[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Dickey et al., 2007 Dickey, M. W., Choy, J. J. and Thompson, C. K. 2007. Real-time comprehension of Wh-movement in aphasia: Evidence from eyetracking while listening. Brain and Language, 100: 1–22. doi: 10.1016/j.bandl.2006.06.004[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) found that divergences exist in IWAs' sentence-processing routines depending on whether they comprehended non-canonical sentences correctly or not, pointing rather to a processing deficit explanation.

Aims: The aim of the current study was to investigate agrammatic IWAs' online and offline sentence comprehension simultaneously in order to reveal what online sentence-processing strategies they rely on and how these differ from controls' processing routines. We further asked whether IWAs' offline chance performance for non-canonical sentences does indeed result from guessing.

Methods & Procedures: We used the visual-world paradigm and measured eye movements (as an index of online sentence processing) of controls (N?=?8) and individuals with aphasia (N?=?7) during a sentence–picture matching task. Additional offline measures were accuracy and reaction times.

Outcomes & Results: While the offline accuracy results corresponded to the pattern predicted by the TDH, IWAs' eye movements revealed systematic differences depending on the response accuracy.

Conclusions: These findings constitute evidence against attributing IWAs' chance performance for non-canonical structures to mere guessing. Instead, our results support processing deficit explanations and characterise the agrammatic parser as deterministic and inefficient: it is slowed down, affected by intermittent deficiencies in performing syntactic operations, and fails to compute reanalysis even when one is detected.     

Double dissociation of letter and category fluency following left frontal and temporal lobe lesions

Background: A number of studies have suggested that temporal cortex is critical for the ability to generate exemplars belonging to a particular semantic category (i.e., category fluency), while frontal cortex is critical for generating words beginning with a particular letter (i.e., letter or phonemic fluency). However, previous studies have often focused on relative, quantitative differences in performance across groups of patients and primarily in the oral domain.

Aims: The current study analysed verbal fluency data from two individuals with chronic aphasia, one with a large left temporal lobe lesion and a severe Wernicke's aphasia, and a second individual with a large left frontal lobe lesion and a moderately severe non-fluent aphasia. The goal of the study was to do both qualitative and quantitative analyses of letter and category fluency performance in these two individuals across oral and written fluency domains.

Methods & Procedures: Participants were administered both oral and written versions of letter fluency (FAS) and category fluency conditions (fruits, animals, and supermarket items). Participants were given 90 seconds to generate as many items as possible, and their responses were scored for both overall output, as well as qualitative structure using a clustering analysis.

Outcomes & Results: The individual with an extensive temporal lobe lesion generated a large number of exemplars on the letter fluency task. Some of these items were neologisms (e.g., frest, anth, and swink), but remarkably all adhered to the phonological constraints of the task. However, this individual was very poor at generating items belonging to semantic categories. In contrast, the individual with a large frontal lesion generated many exemplars on the category fluency task but only two items on the letter fluency task. The same pattern was replicated in the written domain in both individuals, and results from the clustering analysis paralleled these quantitative findings.

Conclusions: This report describes two individuals with aphasia who exhibited a double dissociation between letter and category fluency performance in both oral and written domains. The current findings provide further evidence for the notion that left frontal cortex is critical for word retrieval based on phonology, while left temporal cortex is critical for word retrieval based on semantics. The findings have implications for the types of strategies that may be most effective in individuals with lesions to these brain regions critical for word retrieval.     

Using treatment to improve the production of emotive adjectives in aphasia: a single-case study

ABSTRACT

Background: Emotive adjectives are used in everyday conversations to express opinions and feelings and make evaluations (e.g., “interesting”, “intelligent”). It has been reported that people with aphasia have difficulty using emotive language and that they would like this to be targeted in therapy. However, the literature provides little guidance whether it is possible to improve production of emotive adjectives.

Aims: Our aim was to test the hypothesis that a treatment technique that has been found to be effective in improving noun and verb retrieval (Repetition in the Presence of a Picture) would be effective in improving production of emotive adjectives.

Methods & Procedures: This study involved GEC, a 66-year-old English-speaking man who presented with non-fluent aphasia including frequent word-finding difficulties and impaired production of emotive adjectives following a left-hemisphere stroke. Treatment was carried out using a single-subject multiple-baseline design consisting of two treatment periods each of 2 weeks preceded by four baseline measurements, with one within-treatment measurement and three post-treatment measurements (immediately, 1-week, and 11 weeks after the end of the treatment programme). The treatment comprised weekly meetings with the therapist and computer-presented, self-paced, home-practice using to treat 72 emotive adjectives (36 positive and 36 negative adjectives) associated with 24 pictures.

Outcomes & Results: GEC’s ability to produce treated adjectives for treated pictures significantly improved. The effect was maintained for the positive items with maintenance for negative items close to significant. However, these item-specific effects of treatment did not generalise: No significant improvement was observed in producing new, untreated labels for the treated pictures. Nor was GEC able to use treated labels with pictures other than those with which they were treated. In addition, GEC’s performance in a connected speech task remained unchanged. These results indicate that the treatment effects were not only item-specific but also task-specific.

Conclusions: This study provides the first demonstration that emotive adjective retrieval may be improved using a treatment method similar to that commonly used for treating nouns and verbs. This result was achieved after only 2 weeks of practice at home with a computer including sparse meetings with a therapist and targeting only single-word production of adjectives. While there was no evidence of generalisation across items or tasks, this study encourages further exploration of the topic. This should include replication across participants and the inclusion of more natural conversational tasks in the treatment to facilitate transfer.     

Impairment‐ and activity/participation‐directed interventions in progressive language impairment: Clinical and theoretical issues

Abstract

The most salient and discussed features of agrammatism are the omission and substitution of grammatical morphemes, whether bound or free, in speech production. Cross-linguistic studies have shown that language-specific features determine the pattern of omissions and substitutions found; morphological markers are almost never omitted if the resulting form is a non-word; substitutions are mis-selections from existing paradigms. In the present paper we investigate the ways in which agrammatism is manifested in Algerian Arabic, a Semitic language where simple (Ø-prefixed and Ø-suffixed) words are described as consisting of three morphemes: the discontinuous consonantal root, the discontinuous vocalic base and a CV template or skeleton (McCarthy 1975). Our findings are comparable to those previously reported, in that the three agrammatic subjects who participated in this study do omit and substitute free-standing and bound grammatical markers, and never produce non-words. More specifically, their performance is characterized by omissions of linear bound morphemes in prefixed and suffixed words, as well as substitutions of morphologically complex forms by simpler and more frequent ones. An interpretation of the subjects' performance in the light of current linguistic and psycholinguistic theories on the lexicon is proposed.     

Tense processing in Broca's and Wernicke's aphasia

Background: Evidence from the picture–word interference literature reveals that picture–word pairs bearing a non-categorical relationship (e.g., RING—expensive) will facilitate naming more than picture–word pairs bearing a categorical relationship (e.g., BRACELET—earrings). It is not known whether these differential effects would be found within a naming treatment paradigm for aphasia; however, if it is the case that one type of semantic relations will yield more robust treatment effects than another, this would provide a more efficient and effective delivery of treatment. Moreover, since semantic errors are commonly produced by individuals with aphasia, an approach which helps strengthen the semantic network will, in turn, strengthen lexical retrieval and access processes.

Aim: The aim of the study was to compare a features condition, or a condition in which attributes were used, to a categorical condition, or a condition in which categorical members were used to see which would yield greater naming improvements in aphasia.

Methods &; Procedures: Eight individuals with aphasia were recruited for the study. A multiple-baseline design across behaviours with a crossover component was used. A categorical–features sequence was used in four participants, and a features–categorical sequence was used in four other participants. Accuracy of correct naming was calculated to determine improvements in treatment. The types of naming errors produced by individuals with positive treatment effects in the trained condition were compared to the types of naming errors produced in the control condition.

Outcome &; Results: A range of small to large treatment effect sizes was obtained in six of the eight participants when considering both treated conditions. However, no overwhelming advantage was found for either condition. Analyses of naming error patterns indicated increased lexical access and retrieval of the targeted picture name.

Conclusions: Approaches that use cues focusing either on categorical membership or attributes will facilitate naming abilities in individuals with aphasia whether naming per cent accuracy is calculated or naming error types are tallied. However, the current results did not indicate an overwhelming advantage in using one or the other condition. Future studies should specify the type of features used (e.g., associative cues, thematic cues or perceptual cues) to determine whether such a differentiation will yield clearer differential treatment effects.     

The negotiation of intelligibility in an aphasic dyad

Employing conversation analysis as a research technique, this study investigates the ways that unintelligibility is accounted for and overcome within a therapeutic encounter between an individual with aphasia and dysarthria and his clinician. The results emphasize the collaborative nature of intelligibility negotiation and demonstrate how both the individual with the impairment and his clinician employ various interactional strategies and knowledge resources to turn unintelligibility into intelligibility so that the therapeutic encounter may continue.     

Conversational treatment in mild aphasia: A case study

Background: The literature suggests that mild aphasia negatively affects everyday experiences, social life, and identity. However, while mild word‐finding problems and difficulty understanding abstract or grammatically complex language are typical clinical characteristics, their impact on everyday discourse and conversation partners remains relatively unexplored. Similarly, treatment studies addressing conversational difficulties have predominantly included those with moderate to severe aphasia, rather than those at the mild end of the severity scale.

Aims: The current study examines conversational difficulties in mild aphasia and their accessibility to a conversational treatment procedure.

Methods & Procedures: A woman with mild aphasia and her husband participated in the study. They underwent 14 sessions of conversational therapy, based on the procedures of Boles (1998 Boles, L. 1998. Conversational discourse analysis as a method for evaluating progress in aphasia: A case report.. Journal of Communication Disorders, 31: 261–274. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and Boles and Lewis (2003 Boles, L. and Lewis, M. 2003. Working with couples: Solution based aphasia therapy.. Asia Pacific Journal of Speech, Language and Hearing, 8: 153–159. [Taylor & Francis Online] , [Google Scholar]). Outcome measures included subjective ratings by the couple regarding conversational parameters they deemed important, ratings of their interactions by independent judges on the Measure of skill in Supported Conversation (MSC) and the Measure of Participation in Conversation (MPC) (Kagan et al., 2004 Kagan, A., Winckel, J., Black, S., Felson Duchan, J., Simmons‐Mackie, N. and Square, P. 2004. A set of observational measures for providing support and participation in conversation between adults with aphasia and their conversation partners.. Topics in Stroke Rehabilitation, 11(1): 67–83. [Taylor & Francis Online] , [Google Scholar]), independent judgments of whether interactions were pre or post‐treatment, as well as a series of behavioural measures related to specific goals collaboratively set by the couple and the clinician.

Outcomes & Results: Improvements were noted in both the participants’ ratings and the independent judges’ ratings. While some changes were noted on behavioural measures, clear patterns were not always evident.

Conclusions: The study suggests that conversational treatment may be beneficial to couples dealing with mild aphasia as well as those at the more severe end of the continuum as reported previously. However, measures of the effects of treatment need to be further explored in terms of sensitivity to conversational changes in mild aphasia.