@article{BastiaanseWielingWolthuis2016,
  author    = {Bastiaanse, Roelien and Wieling, Martijn and Wolthuis, Nienke},
  title     = {The role of frequency in the retrieval of nouns and verbs in aphasia},
  series = {Aphasiology : an international, interdisciplinary journal},
  volume    = {30},
  journal   = {Aphasiology : an international, interdisciplinary journal},
  publisher = {Karger},
  address   = {Abingdon},
  issn      = {0268-7038},
  doi       = {10.1080/02687038.2015.1100709},
  pages     = {1221 -- 1239},
  year      = {2016},
  abstract  = {Background: Word retrieval in aphasia involves different levels of processinglemma retrieval, grammatical encoding, lexeme retrieval, and phonological encodingbefore articulation can be programmed and executed. Several grammatical, semantic, lexical, and phonological characteristics, such as word class, age of acquisition, imageability, and word frequency influence the degree of success in word retrieval. It is, however, not yet clear how these factors interact. The current study focuses on the retrieval of nouns and verbs in isolation and in sentence context and evaluates the impact of the mentioned factors on the performance of a group of 54 aphasic speakers.Aims: The main aim is to measure the effect of word frequency on the retrieval of nouns and verb by disentangling the influence of word class, age of acquisition, imageability, and lemma and lexeme frequencies on word retrieval in aphasia.Methods \& Procedures: Four tests for retrieval of nouns, verbs in isolation, and infinitives and finite verbs were administered to 54 aphasic speakers. The influence of lemma and lexeme frequency, Age of Acquisition on the word retrieval abilities was analysed.Outcomes and Results: Word class, age of acquisition, and imageability play a significant role in the retrieval of nouns and verbs: nouns are easier than verbs; the earlier a word has been learned and the more concrete it is, the easier it is to retrieve. When performance is controlled for these factors, lemma frequency turns out to play a minor role: only in object naming does it affect word retrieval: the higher the lemma frequency of a noun, the easier it is to access. Such an effect does not exist for verbs, neither on an action-naming test, nor when verbs have to be retrieved in sentence context. Lexeme frequency was not found to be a better predictor than lemma frequency in predicting word retrieval in aphasia.Conclusions: Word retrieval in aphasia is influenced by grammatical, semantic, and lexical factors. Word frequency only plays a minor role: it affects the retrieval of nouns, but not of verbs.},
  language  = {en}
}
@article{GroenewoldBastiaanseNickelsetal.2015,
  author    = {Groenewold, Rimke and Bastiaanse, Roelien and Nickels, Lyndsey and Wieling, Martijn and Huiskes, Mike},
  title     = {The differential effects of direct and indirect speech on discourse comprehension in Dutch and English listeners with and without aphasia},
  series = {Aphasiology : an international, interdisciplinary journal},
  volume    = {29},
  journal   = {Aphasiology : an international, interdisciplinary journal},
  number    = {6},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {0268-7038},
  doi       = {10.1080/02687038.2014.977217},
  pages     = {685 -- 704},
  year      = {2015},
  abstract  = {Background: In a previous study, we demonstrated that narratives containing direct speech constructions were easier to comprehend than narratives with indirect speech constructions for Dutch listeners with and without aphasia. There were two possible explanations for this finding: either that direct speech has increased liveliness compared to indirect speech or that direct speech is less grammatically complex. Aims: This study aimed to provide further insight into the mechanisms underlying the differences between direct and indirect speech constructions on discourse comprehension in Dutch. More specifically, it aimed to examine the role that the grammatical characteristics of direct and indirect speech play in discourse comprehension success by comparing English- and Dutch-speaking individuals with and without aphasia. Methods \& Procedures: An English version of the Dutch iPad-based Direct Speech Comprehension (DISCO) test was developed. Twenty individuals with aphasia and 19 neurologically healthy control participants were presented with spoken narratives that contained either direct or indirect speech constructions. Their performance was compared to that of the participants of the Dutch DISCO study. To assess the effect of language on performance, we conducted a single analysis in which we contrasted the English data with the Dutch data. Outcomes \& Results: Control participants performed better than participants with aphasia; English-speaking participants performed worse than Dutch participants, and narratives containing direct speech were easier to comprehend than narratives with indirect speech constructions. However, a subsequent analysis including only individuals with aphasia showed that the Dutch group differed from the English-speaking group: direct speech was only beneficial for the Dutch participants with aphasia. Conclusions: This study expanded on the findings of a previous study, in which a facilitating effect of direct over indirect speech constructions for audiovisual discourse comprehension was found. The differential effects of direct speech on comprehension in Dutch and English showed that rather than one or other explanation being "correct", both liveliness and grammatical characteristics play a role in discourse comprehension success. Grammatically less complex constructions (direct speech) are not necessarily always easier to comprehend than grammatically more complex constructions (indirect speech) for individuals with aphasia. In our study grammatically simple constructions introduced grammatical ambiguity and therefore possible interpretation difficulties for the English-speaking participants with aphasia.},
  language  = {en}
}