Multilingualism and verbal short-term/working memory: Evidence from academics.

To date, the evidence regarding the effect of bilingualism/multilingualism on short-term memory (STM) and working memory (WM) capacity is inconclusive. This study investigates whether multilingualism has a positive effect on the verbal STM and WM capacity of neuro typical middle-aged and older individuals. Eighty-two L1-Norwegian sequential bilingual/ multilingual academics were tested with tasks measuring verbal STM/WM capacity. Degree of bilingualism/multilingualism for each participant was estimated based on a comprehensive questionnaire. Different measures of bilingualism/multilingualism were used. Data on potentially influencing non-linguistic factors were also collected. Correlation and regression analyses showed that multilingualism impacts both verbal STM and verbal WM. All analyses showed that number of known foreign languages was the strongest predictor of verbal STM and WM capacity. The results are discussed considering recent studies on the impact of bilingualism on STM/WM and on recent proposals regarding the mechanism underlying so-called bilingual advantage.publishedVersio

Cross-linguistic adaptations of The Comprehensive Aphasia Test: Challenges and solutions

Comparative research on aphasia and aphasia rehabilitation is challenged by the lack of comparable assessment tools across different languages. In English, a large array of tools is available, while in most other languages, the selection is more limited. Importantly, assessment tools are often simple translations and do not take into consideration specific linguistic and psycholinguistic parameters of the target languages. As a first step in meeting the needs for comparable assessment tools, the Comprehensive Aphasia Test is currently being adapted into a number of languages spoken in Europe. In this article, some key challenges encountered in the adaptation process and the solutions to ensure that the resulting assessment tools are linguistically and culturally equivalent, are proposed. Specifically, we focus on challenges and solutions related to the use of imageability, frequency, word length, spelling-to-sound regularity and sentence length and complexity as underlying properties in the selection of the testing material

Imageability ratings across languages

Imageability is a psycholinguistic variable that indicates how well a word gives rise to a mental image or sensory experience. Imageability ratings are used extensively in psycholinguistic, neuropsychological, and aphasiological studies. However, little formal knowledge exists about whether and how these ratings are associated between and within languages. Fifteen imageability databases were cross-correlated using nonparametric statistics. Some of these corresponded to unpublished data collected within a European research network-the Collaboration of Aphasia Trialists (COST IS1208). All but four of the correlations were significant. The average strength of the correlations (rho = .68) and the variance explained (R (2) = 46%) were moderate. This implies that factors other than imageability may explain 54% of the results. Imageability ratings often correlate across languages. Different possibly interacting factors may explain the moderate strength and variance explained in the correlations: (1) linguistic and cultural factors; (2) intrinsic differences between the databases; (3) range effects; (4) small numbers of words in each database, equivalent words, and participants; and (5) mean age of the participants. The results suggest that imageability ratings may be used cross-linguistically. However, further understanding of the factors explaining the variance in the correlations will be needed before research and practical recommendations can be made

Pathological language-switching/mixing and its relationship to domain-general cognitive control

This chapter constitutes a narrative review on the so-called pathological language mixing and switching, with primary focus on multilingual persons with aphasia. Domain-general cognitive control is assumed to be a central aspect of bilingual language use and is strongly involved in switching between languages. However, this assumed relationship has not received the empirical scrutiny it deserves. In this review, we ask whether and when language switching/mixing in brain-damaged participants should be considered a control deficit and when it can be better characterized as a communicative strategy of the participants. We present opposing views on the legitimacy of using the term pathological switching/mixing and propose a way of reconciling these views. We also ask to what extent possible language control deficits underlying so-called pathological switching/mixing overlap with domain-general cognitive control functions, as measured by tasks of executive functions, and look into the neural correlates of these functions. This question addresses the relationship between language control and domain-general cognitive control. It therefore also touches upon the underlying assumptions behind the idea that frequent language switching/mixing could train cognitive control functions, possibly leading to a bilingual advantage in cognitive abilities, a hotly debated topic

Pathological language-switching/mixing and its relationship to domain-general cognitive control

This chapter constitutes a narrative review on the so-called pathological language mixing and switching, with primary focus on multilingual persons with aphasia. Domain-general cognitive control is assumed to be a central aspect of bilingual language use and is strongly involved in switching between languages. However, this assumed relationship has not received the empirical scrutiny it deserves. In this review, we ask whether and when language switching/mixing in brain-damaged participants should be considered a control deficit and when it can be better characterized as a communicative strategy of the participants. We present opposing views on the legitimacy of using the term pathological switching/mixing and propose a way of reconciling these views. We also ask to what extent possible language control deficits underlying so-called pathological switching/mixing overlap with domain-general cognitive control functions, as measured by tasks of executive functions, and look into the neural correlates of these functions. This question addresses the relationship between language control and domain-general cognitive control. It therefore also touches upon the underlying assumptions behind the idea that frequent language switching/mixing could train cognitive control functions, possibly leading to a bilingual advantage in cognitive abilities, a hotly debated topic

Functional categories in greek agrammatism

The present study, which is conducted within the general framework of Generative Grammar (Chomsky, 1981; 1995 and thereafter), investigates the ability of three Greek-speaking agrammatic aphasics to handle (in both production and comprehension) a number of functional categories: Complementizer (C), Negation (Neg), Agreement (Agr), Tense (T), and Aspect (Asp). To test these categories, a series of structured tasks were administered (e.g. question elicitation task, constituent ordering task, truth-value judgement task, sentence completion task, sentence grammaticality judgement task, sentence completion task, sentence grammatically judgement task, sentence repetition task, etc). Apart from the afore-mentioned categories, the effect of some other variables on the agrammatic performance was also explored, such as the frequency of occurrence and the morphological regularity of the verb, as well as the structural complexity of the sentence. One of the principle goals of this study is to test some accounts of agrammatism proposed so far, such as the Tree Pruning Hypothesis (TPH) (Friedmann & Grodzinsky, 1997) and the Interpretable Features’ Impairment Hypothesis (IFIH) (Nanousi, Masterson, Druks, & Atkinson, 2006; Varlokosta, Valeonti, Kakavoulia, Lazaridou, Economou, & Protopapas, 2006). According to TPH, agrammatism arises from deletion or ‘pruning’ of the syntactic tree at the T node. TPH predicts that everything above T is lost while material below is preserved. On the other hand, IFIH is not structural/hierarchical in nature, as it predicts that in agrammatism the most severe impairment will involve the functional categories with interpretable features (such as T and Asp) rather than the ones with uninterpretable features (such as Agr). The results of the present study are in line with IFIH, since T, Asp, Neg and C –which all bear interpretable features– were found to be severely impaired, while Agr was found relatively spared. In contrast, given that Asp is lower that T and Agr in the Greek syntactic hierarchy (Philippaki-Warburton, 1998), these results cannot be accountted for by TPH. Apart from reinforcing the descriptive adequacy of IFIH, this study aimed at developing its interpretative enrichment as well. More specifically, on the basis of the quantitative and qualitative aspects of the agrammatic patterns of our participants, it is argued that they have two deficits: a linguistic one, which is mainly syntactic in nature affecting functional categories across the board, and a “psychological/cognitive” one, namely a limitation of processing resources. Therefore, it is suggested that what renders the categories with interpretable features more vulnerable than those with uninterpretable features is the synergistic effect of three facts: i) agrammatic speakers (at least the ones participated in the present study) suffer from a reduction of processing resources, ii) they have a syntactic deficit affecting functional categories, and iii) the categories with interpretable features are more demanding in terms of processing resources, as they require integration of grammatical and conceptual knowledge. In contrast, implementation of only grammatical knowledge is sufficient for “uninterpretable” categories like Agr. Finally, similar but not identical patterns of performance were observed across different modalities (comprehension and production), reinforcing the weak (and not the strong) parallelism between them and, thus, providing empirical support to Grodzinsky’s claim (2000: 18) that there is anatomical proximity, but functional separation between production and comprehension mechanisms.Αντικείµενο της παρούσας µελέτης είναι η διερεύνηση της υπόστασης των λειτουργικών κατηγοριών στα ελληνόφωνα άτοµα µε αγραµµατισµό. Ειδικότερα, οι προς διερεύνηση λειτουργικές κατηγορίες είναι o συµπληρωµατικός δείκτης (Σ∆), η άρνηση, η συµφωνία, ο χρόνος και η όψη. Ο έλεγχος αυτών των κατηγοριών, που αφορά τόσο την παραγωγή όσο και την κατανόηση, πραγµατοποιείται µέσω της διενέργειας µιας σειράς από δοµηµένες δοκιµασίες, όπως είναι η δοκιµασία εκµαίευσης ερωτήσεων, η δοκιµασία διάταξης συστατικών, η δοκιµασία κρίσης αληθειακής τιµής, η δοκιµασία συµπλήρωσης πρότασης, η δοκιµασία κρίσης γραµµατικότητας πρότασης κ.ά. Επίσης, πέρα από τις παραπάνω λειτουργικές κατηγορίες, εξετάζεται και η επίδραση άλλων παραµέτρων στην αγραµµατική επίδοση, όπως είναι η συχνότητα και η (µορφολογική) οµαλότητα του ρήµατος, καθώς και η δοµική πολυπλοκότητα της πρότασης. Το θεωρητικό πλαίσιο αυτής της µελέτης, πέρα από τις έννοιες που συνδέονται µε την αφασία και τον αγραµµατισµό και πέρα από τα ευρήµατα και πορίσµατα των σχετικών νευρογλωσσολογικών ερευνών που έχουν πραγµατοποιηθεί, έχει διττή ταυτότητα: τη γλωσσολογική και την ψυχολογική. Γλωσσολογικό υπόβαθρο αποτελεί το ευρύτερο πλαίσιο της γενετικής γραµµατικής, όπως αυτό ορίζεται βάσει των πιο πρόσφατων εκδοχών της: του προτύπου κυβέρνησης και αναφορικής δέσµευσης (Chomsky, 1981, 1986α,β) και του µινιµαλιστικού προγράµµατος (Chomsky, 1993, 1994, 1995α,β, 2000, 2001). Το ψυχολογικό υπόβαθρο συγκροτείται από τις σχετικές έννοιες που απαντούν στη βιβλιογραφία (π.χ. ενεργοποίηση αναπαραστάσεων, πόροι επεξεργασίας, βραχυπρόθεσµη µνήµη ή µνήµη εργασίας κ.λπ.), καθώς και από κάποια µοντέλα της βραχυπρόθεσµης µνήµης που είτε άσκησαν µεγάλη επίδραση στο πεδίο της νευροψυχολογίας (π.χ. Baddeley & Hitch, 1974) είτε εστιάζουν ειδικότερα στη γλώσσα, αποτελώντας έτσι χρήσιµα εργαλεία ανάλυσης των αγραµµατικών δεδοµένων (π.χ. Ν. Martin & Saffran, 1992, 1997• R. Martin, Lesch & Bartha, 1999). Αυτή η εργασία, µε την εξέταση των λειτουργικών κατηγοριών στον ελληνικό αγραµµατισµό, φιλοδοξεί –µεταξύ άλλων– να εµπλουτίσει τη βάση των σχετικών δεδοµένων που αφορούν ειδικότερα την Ελληνική, καθώς και να ενισχύσει το διαγλωσσικό έλεγχο της εγκυρότητας διάφορων ερµηνειών του αγραµµατισµού που έχουν προταθεί µέχρι σήµερα (όπως είναι, µεταξύ άλλων, η υπόθεση της αποκοπής του (συντακτικού) δέντρου (Friedmann & Grodzinsky, 1997) και η υπόθεση της διαταραχής των ερµηνεύσιµων χαρακτηριστικών (Nanousi, Masterson, Druks & Atkinson, 2006• Varlokosta, Valeonti, Kakavoulia, Lazaridou, Economou & Protopapas, 2006). [...

Are there prototypical associations between time frames and aspectual values? Evidence from Greek aphasia and healthy ageing

Time reference, which has been found to be selectively impaired in agrammatic aphasia, is often interwoven with grammatical aspect. A recent study on Russian aphasia found that time reference and aspect interact: Past reference was less impaired when tested within a perfective aspect context (compared to when tested within an imperfective aspect context), and reference to the non-past was less impaired when tested within an imperfective aspect context (compared to when tested within a perfective aspect context). To explain this pattern, the authors argued that there are prototypical associations between time frames and aspectual values. The present study explores the relationship between time reference and aspect focusing on Greek aphasia and healthy ageing and using a sentence completion task that crosses time reference and aspect. The findings do not support prototypical matches between different time frames and aspectual values. Building on relevant studies, we propose that patterns of performance of healthy or language-impaired speakers on constrained tasks tapping different combinations of time frames with aspectual values should reflect the relative frequency of these combinations in a given language. The analysis of the results at the individual level revealed a double dissociation, which indicates that a given time frame–aspectual value combination may be relatively easy to process for some persons with aphasia but demanding for some others

Pathological language-switching/mixing and its relationship to domain-general cognitive control

This chapter constitutes a narrative review on the so-called pathological language mixing and switching, with primary focus on multilingual persons with aphasia. Domain-general cognitive control is assumed to be a central aspect of bilingual language use and is strongly involved in switching between languages. However, this assumed relationship has not received the empirical scrutiny it deserves. In this review, we ask whether and when language switching/mixing in brain-damaged participants should be considered a control deficit and when it can be better characterized as a communicative strategy of the participants. We present opposing views on the legitimacy of using the term pathological switching/mixing and propose a way of reconciling these views. We also ask to what extent possible language control deficits underlying so-called pathological switching/mixing overlap with domain-general cognitive control functions, as measured by tasks of executive functions, and look into the neural correlates of these functions. This question addresses the relationship between language control and domain-general cognitive control. It therefore also touches upon the underlying assumptions behind the idea that frequent language switching/mixing could train cognitive control functions, possibly leading to a bilingual advantage in cognitive abilities, a hotly debated topic