Denise McCall

Training on an iconic communication system for severe aphasia can improve natural language production.

Abstract Two patients with chronic Brocas aphasia were trained in the production of locative prepositional phrases and S–V–O sentences on C-VIC, an alternative communication system. After training, their verbal production of these constructions improved markedly. The implications of these results for shared processes between natural language production and C-VIC production are discussed.

Remediating production of tense morphology improves verb retrieval in chronic aphasia

Production of tense markers in C-VIC, a computerized visual communication system, was utilized as a treatment for three patients with severe expressive aphasia. Patients practiced constructing C-VIC tense marked sentences and then producing English equivalents. After training, all patients demonstrated significant improvements in English verb retrieval and production of correct tense morphology. Generalization of morphological rules for past tense production was seen for regular, but not irregular verbs. These results support the LaPointe and Dell (1989) extension of the Garrett (1975, 1992) model specifying a search through so-called verb phrase notion stores as a process mediating transition from functional to positional levels, but also suggest an additional constraint on the output of the verb notion store search.

The role of processing support in the remediation of aphasic language production disorders

Performance factors such as resource or memory limitations, as opposed to loss of linguistic knowledge per se, are increasingly implicated in aphasic language impairments. Here we investigate the consequences of this hypothesis for the remediation of aphasic language production. Two nonfluent aphasic subjects used a computerised communication system (CS) to practice narrative production. The CS serves primarily as a processing prosthesis, allowing the user to record spoken sentence elements, replay these elements, and build them up into larger structures by manipulating icons on the screen. Use ofthe CS in conjunction with explicit training of syntactic structure has been reported to bring about gains in unaided language production. Here we examine the treatment impact or CS-based processing support alone. Eleven weeks of independent home use of the CS resulted in some marked changes in one subjects production of unaided spoken narratives. The most striking and consistent changes involved more structured and informative speech. The second subject, who presented with far more severe lexical impairments, did not show comparable gains in the structural properties of his unaided speech, but was able to produce markedly more structured narratives when aided by the CS. These results support the performance hypothesis because the CS provided no structure-modelling or feedback. In addition, the first subjects treatment gains indicate that practising narrative production with processing support may be effective in bringing about increased structural complexity and informativeness in aphasic speech. This is congruent with other claims in the literature that increasing the complexity or difficulty of the training material may in some cases increase the efficacy of the treatment.

Generalization from Single Sentence to Multisentence Production in Severely Aphasic Patients

Multisentence production was examined in three nonfluent aphasic patients who had undergone a single sentence production training program using a computerized visual communication system (C-VIC). Patients were required to describe videotaped vignettes in English and using C-VIC. C-VIC allowed for an investigation of production abilities previously impossible to measure in severely aphasic patients, since C-VIC does not require internal generation of appropriate lexical items or phonological and articulatory realization. Results are discussed in the context of language production models in an attempt to determine the breakdown(s) in the production system that result in difficulty in trying to produce multiple sentences.

Training agrammatic subjects on passive sentences : Implications for syntactic deficit theories

We trained two subjects with chronic agrammatic aphasia on production of passive sentences using a computerized, iconic-based communication system. After training, one of the subjects demonstrated significant improvements in his abilities to comprehend and verbally produce English passive voiced sentences, including sentences with conjoined subjects and objects. These results suggest that agrammatism does not represent a fixed syntactic deficit.

Differentiating globally aphasic patients: Data from in-depth language assessments and production training using C-VIC

Abstract It is commonly assumed that globally aphasic patients retain little or no propositional language abilities. Data are presented from six patients classified as globally aphasic who participated in a computer-based language production training program (C-VIC). Utilization of the C-VIC training program allowed for assessment of language skills, such as sentence production, that previously have been difficult to measure in globally aphasic patients. The results from language assessments and training data indicate some residual language skills in these patients, both in language comprehension and production. Implications as to the usefulness of augmentative communication systems for globally aphasic patients are discussed.

The utility of computerized visual communication for improving natural language in chronic global aphasia: Implications for approaches to treatment in global aphasia

A computerized communication system (C-VIC) was employed as a diagnostic and therapeutic tool to identify propositional language abilities in a chronic, globally aphasic patient. The patient demonstrated the ability to construct sentences during training according to abstract syntax-like rules by manipulating iconic symbols representing nouns and verbs. Further, he produced correct symbolic order to express the thematic relationships in sentences. The effect of C-VIC as a therapeutic intervention to improve the patients natural language abilities was examined using pre- and post-training assessments. Improvements specific to training were observed but neither improvements in natural language nor generalization to production of multiple sentences using C-VIC was found. The results are discussed with regard to current debates concerning treatment approaches and the use of augmentative communication devices for globally aphasic patients.

Representation of Linguistic Rules in the Brain: Evidence from Training an Aphasic Patient to Produce Past Tense Verb Morphology☆

We trained a patient with expressive aphasia and a deficit in phoneme-to-grapheme conversion to produce spoken English verbs with correct tense morphology. After training, he showed evidence of generalization to production of written regular, but not irregular, verbs in a sentence completion task. These data support dual-route, rule-based models within the brain for morphosyntactic operations.

Thematic role assignment in two severely aphasic patients: associations and dissociations.

Two severely aphasic patients were compared in their abilities to comprehend and produce locative prepositional phrases and reversible S-V-O sentences using English and C-VIC, a computer-based iconographic communication system. One patient demonstrated a significant dissociation between his performance in interpreting symbol order in C-VIC prepositional phrases vs. S-V-O sentences. Patients were able to comprehend order in C-VIC S-V-O sentences significantly better than they were able to assign symbol order when they produced these sentences. These data suggest that the procedures for assigning thematic roles to nouns in sentences are at least partially distinct for comprehension and production and that the ordering of nouns around prepositions involves conceptual processes distinct from those involved in ordering nouns around verbs.

Narrative and procedural discourse production by severely aphasic patients.

Five chronically aphasic subjects were trained on a computerized iconographic communication system (C-VIC). Their performance in producing single sentences, scripts, and narratives was assessed using both spoken English and C-VIC. The requisite vocabulary necessary and the narrative complexity of the target productions were controlled. Subject performance using C-VIC indicates that the ability to construct discourse at the macrostructural level is largely intact. Despite significant improvements in spoken production after C-VIC training, especially at the single sentence level, the subjects’ spoken discourse remains severely impaired by their failures at the microlinguistic level. These results point to the limits of currently available approaches to the remediation of aphasia and suggest avenues for future research.