Publications

Abstract

Background

Forced switching between languages poses demands on control abilities, which may be difficult to meet for bilinguals with aphasia. Freely choosing languages has been shown to increase naming efficiency in healthy bilinguals, and lexical accessibility was found to be a predictor for language choice. The overlap between bilingual language switching and other types of switching is yet unclear.

Aims

This study aimed to examine the benefits of free language choice for bilinguals with aphasia and to investigate the overlap of between- and within-language switching abilities.

Methods & Procedures

Seventeen bilinguals with aphasia completed a questionnaire and four web-based picture naming tasks: single-language naming in the first and second language separately; voluntary switching between languages; cued and predictable switching between languages; cued and predictable switching between phrase types in the first language. Accuracy and naming latencies were analysed using (generalised) linear mixed-effects models.

Outcomes & Results

The results showed higher accuracy and faster naming for the voluntary switching condition compared to single-language naming and cued switching. Both voluntary and cued language switching yielded switch costs, and voluntary switch costs were larger. Ease of lexical access was a reliable predictor for voluntary language choice. We obtained no statistical evidence for differences or associations between switch costs in between- and within-language switching.

Conclusions

Several results point to benefits of voluntary language switching for bilinguals with aphasia. Freely mixing languages improved naming accuracy and speed, and ease of lexical access affected language choice. There was no statistical evidence for overlap of between- and within-language switching abilities. This study highlights the benefits of free language choice for bilinguals with aphasia.

Abstract

Previous research examining the factors that determine language choice and voluntary switching mainly involved early bilinguals. Here, using picture naming, we investigated language choice and switching in late Dutch–English bilinguals. We found that naming was overall slower in cued than in voluntary switching, but switch costs occurred in both types of switching. The magnitude of switch costs differed depending on the task and language, and was moderated by L2 proficiency. Self-rated rather than objectively assessed proficiency predicted voluntary switching and ease of lexical access was associated with language choice. Between-language and within-language switch costs were not correlated. These results highlight self-rated proficiency as a reliable predictor of voluntary switching, with language modulating switch costs. As in early bilinguals, ease of lexical access was related to word-level language choice of late bilinguals.

Abstract

Disagreement exists about whether lexical selection in word production is a competitive process. Competition predicts semanticinterference from distractor words in immediate but not in delayed picture naming. In contrast, Janssen, Schirm, Mahon, and Caramazza (2008) obtained semanticinterference in delayed picture naming when participants had to decide between picture naming and oral reading depending on the distractor word’s colour. We report three experiments that examined the role of such taskdecisions. In a single-task situation requiring picture naming only (Experiment 1), we obtained semanticinterference in immediate but not in delayednaming. In a task-decision situation (Experiments 2 and 3), no semantic effects were obtained in immediate and delayed picture naming and word reading using either the materials of Experiment 1 or the materials of Janssen et al. (2008). We present an attentional account in which taskdecisions may hide or reveal semanticinterference from lexical competition depending on the amount of parallelism between task-decision and picture–word processing.

Abstract

E. Dhooge and R. J. Hartsuiker (2010) reported experiments showing that picture naming takes longer with low- than high-frequency distractor words, replicating M. Miozzo and A. Caramazza (2003). In addition, they showed that this distractor-frequency effect disappears when distractors are masked or preexposed. These findings were taken to refute models like WEAVER++ (A. Roelofs, 2003) in which words are selected by competition. However, Dhooge and Hartsuiker do not take into account that according to this model, picture-word interference taps not only into word production but also into attentional processes. Here, the authors indicate that WEAVER++ contains an attentional mechanism that accounts for the distractor-frequency effect (A. Roelofs, 2005). Moreover, the authors demonstrate that the model accounts for the influence of masking and preexposure, and does so in a simpler way than the response exclusion through self-monitoring account advanced by Dhooge and Hartsuiker

Abstract

It has been argued that inhibition is a mechanism of attentional control in bilingual language performance. Evidence suggests that effects of inhibition are largest in the tail of a response time (RT) distribution in non-linguistic and monolingual performance domains. We examined this for bilingual performance by conducting delta-plot analyses of naming RTs. Dutch-English bilingual speakers named pictures using English while trying to ignore superimposed neutral Xs or Dutch distractor words that were semantically related, unrelated, or translations. The mean RTs revealed semantic, translation, and lexicality effects. The delta plots leveled off with increasing RT, more so when the mean distractor effect was smaller as compared with larger. This suggests that the influence of inhibition is largest toward the distribution tail, corresponding to what is observed in other performance domains. Moreover, the delta plots suggested that more inhibition was applied by high- than low-proficiency individuals in the unrelated than the other distractor conditions. These results support the view that inhibition is a domain-general mechanism that may be optionally engaged depending on the prevailing circumstances.

Abstract

E. Dhooge and R. J. Hartsuiker (2010) reported experiments showing that picture naming takes longer with low- than high-frequency distractor words, replicating M. Miozzo and A. Caramazza (2003). In addition, they showed that this distractor-frequency effect disappears when distractors are masked or preexposed. These findings were taken to refute models like WEAVER++ (A. Roelofs, 2003) in which words are selected by competition. However, Dhooge and Hartsuiker do not take into account that according to this model, picture-word interference taps not only into word production but also into attentional processes. Here, the authors indicate that WEAVER++ contains an attentional mechanism that accounts for the distractor-frequency effect (A. Roelofs, 2005). Moreover, the authors demonstrate that the model accounts for the influence of masking and preexposure, and does so in a simpler way than the response exclusion through self-monitoring account advanced by Dhooge and Hartsuiker

Abstract

P. A. Starreveld and W. La Heij (1995) tested the seriality view of lexical access in speech production, according to which lexical selection and the encoding of a word's form proceed in serial order without feedback. In 2 experiments, they looked at the combined effect of semantic and orthographic relatedness of written distracter words in tasks that required conceptually driven naming. They found an interaction between semantic relatedness and orthographic relatedness and argued that the observed interaction refutes the seriality view of lexical access. In this comment, the authors argue that Starreveld and La Heij's rejection of serial access was based on an oversimplified conception of the seriality view and that interaction, rather than additivity, is predicted by existing conceptions of serial access.