Purpose The goal of this project was to examine if there was a principled way to understand the nature of rehabilitation in bilingual aphasia such that patterns of acquisition and generalization are predictable and logical. Methods Seventeen Spanish-English bilinguals with aphasia participated in the therapy experiment. For each participant, three sets of stimuli were developed for each language: (a) English Set 1, (b) English Set 2 (semantically related to each item in English Set 1), (c) English Set 3 (unrelated control items), (d) Spanish Set 1 (translations of English Set 1), (e) Spanish Set 2 (translations of English Set 2; semantically related to each item in Spanish Set 1), and (f) Spanish Set 3 (translations of English Set 3; unrelated control items). A single subject experimental multiple baseline design across participants was implemented. Treatment was conducted in one language whereas generalization to within and between-language untrained items was examined. Results Treatment for naming on Set 1 items resulted in significant improvement (ES > 4.0) on the trained items in 14/17 participants. Of the 14 participants who showed improvement, within-language generalization to semantically related items was observed in 10 participants. Between-language generalization to the translations of trained items was observed for 5 participants; whereas between-language generalization to the translations of the untrained semantically related items was observed for 6 participants. Conclusions The results of this study demonstrate within and between-language patterns that are variable across participants, these differences are indicative of the interplay between facilitation (generalization) and inhibition.

This study examines language control deficits in bilingual aphasia in terms of domain specific cognitive control and domain general cognitive control. Thirty Spanish-English controls and ten Spanish-English adults with aphasia completed the flanker task and a word-pair relatedness judgment task. All participants exhibited congruency effects on the flanker task. On the linguistic task, controls did not show the congruency effect on the first level analysis. However, conflict ratios revealed that the control group exhibited significant effects of language control. Additionally, individual patient analysis revealed overall positive and negative effects of language control impairment and a benefit from semantically related word-pairs. Patient data suggest a dissociation between the mechanisms of language control and cognitive control, thus providing evidence for domain specific cognitive control. The influence of language proficiency on speed of translation was also examined. Generally, controls were faster when translating into their dominant language, whereas the patients did not show the same trends.

Purpose We report on a study that replicates previous treatment studies using Abstract Semantic Associative Network Training (AbSANT), which was developed to help persons with aphasia improve their ability to retrieve abstract words, as well as thematically related concrete words. We hypothesized that previous results would be replicated; that is, when abstract words are trained using this protocol, improvement would be observed for both abstract and concrete words in the same context-category, but when concrete words are trained, no improvement for abstract words would be observed. We then frame the results of this study with the results of previous studies that used AbSANT to provide better evidence for the utility of this therapeutic technique. We also discuss proposed mechanisms of AbSANT. Method Four persons with aphasia completed one phase of concrete word training and one phase of abstract word training using the AbSANT protocol. Effect sizes were calculated for each word type for each phase. Effect sizes for this study are compared with the effect sizes from previous studies. Results As predicted, training abstract words resulted in both direct training and generalization effects, whereas training concrete words resulted in only direct training effects. The reported results are consistent across studies. Furthermore, when the data are compared across studies, there is a distinct pattern of the added benefit of training abstract words using AbSANT. Conclusion Treatment for word retrieval in aphasia is most often aimed at concrete words, despite the usefulness and pervasiveness of abstract words in everyday conversation. We show the utility of AbSANT as a means of improving not only abstract word retrieval but also concrete word retrieval and hope this evidence will help foster its application in clinical practice.

Purpose The purpose of this study is to examine pre-morbid language proficiency and lexical and semantic processing deficits in bilingual aphasia and develop a theoretical account of bilingual language processing. Method Nineteen Spanish-English patients with bilingual aphasia completed a language use questionnaire (LUQ) and were administered Spanish and English standardized language assessments. We analyzed the data to (a) identify patterns of lexical and semantic processing deficits in bilingual aphasia and conceptualize a theoretical framework that accounts for language deficits, (b) determine LUQ measures that predict post-stroke language deficits, and (c) evaluate the relationship between predictive LUQ measures and post-stroke language deficits in order to identify impairment patterns. Results Based on results we obtained significant correlations on several measures between language input and output. We identified pre-stroke language ability rating as the strongest predictor of post-stroke outcomes. Based on this data, two distinct groups were identified: patients who lost the same amount of language in Spanish and English and patients who lost different amounts of Spanish and English. Conclusions Our findings suggest it is possible to identify relationships between language patterns and deficits in patients with bilingual aphasia and that these trends will be instrumental in clinical assessments of this understudied population.

In this study we examined linguistic and non-linguistic control mechanisms in 20 Spanish–English neurologically healthy bilingual adults and 13 Spanish–English bilingual adults with aphasia. Participants completed two linguistic and two non-linguistic control tasks accounting for low and high complexity. Healthy bilingual results were indicative of domain general cognitive control, whereas patient results were indicative of domain specific cognitive control. The magnitude of conflict required to complete the tasks was also examined. Healthy bilinguals exhibited significant amounts of conflict on all tasks and linguistic and non-linguistic conflict ratios were correlated; whereas patient results revealed significant conflict only on non-linguistic tasks and those conflict ratios were not correlated with linguistic conflict ratios, indicating a dissociation between how patients are controlling information in these two domains. Finally, a relationship between language impairment and language control was identified and brain damage was associated with linguistic and non-linguistic task performance.