Time reference in nonfluent and fluent aphasia: a cross-linguistic test of the PAst DIscourse LInking Hypothesis

Recent studies by Bastiaanse and colleagues found that time reference is selectively impaired in people with nonfluent agrammatic aphasia, with reference to the past being more difficult to process than reference to the present or to the future. To account for this dissociation, they formulated the PAst DIscourse LInking Hypothesis (PADILIH), which posits that past reference is more demanding than present/future reference because it involves discourse linking. There is some evidence that this hypothesis can be applied to people with fluent aphasia as well. However, the existing evidence for the PADILIH is contradictory, and most of it has been provided by employing a test that predominantly taps retrieval processes, leaving largely unexplored the underlying ability to encode time reference-related prephonological features. Within a cross-linguistic approach, this study tests the PADILIH by means of a sentence completion task that 'equally' taps encoding and retrieval abilities. This study also investigates if the PADILIH’s scope can be extended to fluent aphasia. Greek- and Italian-speaking individuals with aphasia participated in the study. The Greek group consisted of both individuals with nonfluent agrammatic aphasia and individuals with fluent aphasia, who also presented signs of agrammatism. The Italian group consisted of individuals with agrammatic nonfluent aphasia only. The two Greek subgroups performed similarly. Neither language group of participants with aphasia exhibited a pattern of performance consistent with the predictions of the PADILIH. However, a double dissociation observed within the Greek group suggests a hypothesis that may reconcile the present results with the PADILIH.     

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

ABSTRACT

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.     

Risk associations of melanoma in a Southern European population: results of a case/control study

OBJECTIVES: Limited data exist about the risk factors of melanoma in the Greek population. We investigated the association of melanoma with phenotypic and solar indices in this darker skin population residing in an environment of high ambient ultraviolet radiation. METHODS: Our study included 200 sporadic melanoma cases and 200 age-, sex-matched control subjects. Information on history of sun exposure patterns and cutaneous reaction to sunlight was obtained and a clinical evaluation of pigmentary traits, pigmented lesions, and actinic keratoses was performed. RESULTS: In the multivariate analysis, fair skin (OR: 4.63, for fair skin versus light brown, 95% CI: 1.54-13.92), intermittent sun exposure during childhood (OR: 3.33, >2 weeks/year of sun exposure versus /=10 nevi versus no nevi, 95% CI: 1.65-23.76) and the presence of clinically atypical nevi (OR: 2.84, 95% CI: 1.16-6.98), solar lentigenes were an independent risk factor of melanoma (OR: 4.33, 95% CI: 1.67-11.22). CONCLUSIONS: Intermittent sun exposure of moderate intensity during childhood/adolescence and outdoor leisural activities, in conjunction with a more resistant skin phenotype to acute sunburns and a strong association with nevi and solar lentigenes was a prominent determinant of melanoma risk in our population.     

(Morpho)syntactic comprehension in agrammatic aphasia: Evidence from Greek

Background: A number of hypotheses have been formulated to account for comprehension data in agrammatic aphasia. They explain deficits in comprehending specific structures, such as semantically reversible non-canonical sentences, for example, Trace Deletion Hypothesis (TDH, Grodzinsky, 1986 Grodzinsky, Y. 1986. Language deficit and the theory of syntax. Brain and Language, 27: 135–159. doi:10.1016/0093-934X(86)90009-X[Crossref], [PubMed], [Web of Science ®] , [Google Scholar], 1990 Grodzinsky, Y. 1990. Theoretical perspectives on language deficits, Cambridge, MA: MIT Press. [Crossref] , [Google Scholar], 1995 Grodzinsky, Y. 1995. A restrictive theory of agrammatic comprehension. Brain and Language, 51: 26–51. doi:10.1006/brln.1995.1039[Crossref], [Web of Science ®] , [Google Scholar]), or functional categories, for example, Tree Pruning Hypothesis (TPH, e.g., Friedmann, 2006 Friedmann, N. 2006. Generalizations on variations in comprehension and production: A further source of variation and a possible account. Brain and Language, 96: 151–153. doi:10.1016/j.bandl.2005.06.002[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]); Tense Underspecification Hypothesis (TUH, Wenzlaff & Clahsen, 2004 Wenzlaff, M. and Clahsen, H. 2004. Tense and agreement in German agrammatism. Brain and Language, 89: 57–68. doi:10.1016/S0093-934X(03)00298-0[Crossref], [PubMed], [Web of Science ®] , [Google Scholar], 2005 Wenzlaff, M. and Clahsen, H. 2005. Finiteness and verb-second in German agrammatism. Brain and Language, 92: 33–44. doi:10.1016/j.bandl.2004.05.006[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]); Interpretable Features’ Impairment Hypothesis (IFIH; e.g., Varlokosta et al., 2006 Varlokosta, S., Valeonti, N., Kakavoulia, M., Lazaridou, M., Economou, A. and Protopapas, A. 2006. The breakdown of functional categories in Greek aphasia: Evidence from agreement, tense, and aspect. Aphasiology, 20: 723–743. doi:10.1080/02687030500513703[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). Several studies, however, report evidence contradicting these theories (e.g., Caramazza, Capasso, Capitani, & Miceli, 2005 Caramazza, A., Capasso, R., Capitani, E. and Miceli, G. 2005. Patterns of comprehension performance in agrammatic Broca's aphasia: A test of the Trace Deletion Hypothesis. Brain and Language, 94: 43–53. doi:10.1016/j.bandl.2004.11.006[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Dickey, Milman, & Thompson, 2008 Dickey, M. W., Milman, L. H. and Thompson, C. K. 2008. Judgment of functional morphology in agrammatic aphasia. Journal of Neurolinguistics, 21: 35–65. doi:10.1016/j.jneuroling.2007.08.001[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and propose new accounts to explain the comprehension deficits in agrammatic aphasia, for example, Distributed Morphology Account (DMA, Dickey et al., 2008 Dickey, M. W., Milman, L. H. and Thompson, C. K. 2008. Judgment of functional morphology in agrammatic aphasia. Journal of Neurolinguistics, 21: 35–65. doi:10.1016/j.jneuroling.2007.08.001[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]).

Aims: Against the background above, this study investigates the ability of three Greek-speaking agrammatic individuals to comprehend a wide range of structures and functional categories: semantically reversible (canonical) active and (non-canonical) passive sentences, Complementizer Phrase, subject-verb Agreement, Tense, and Aspect.

Methods & Procedures: We administered: (a) two sentence-picture matching tasks to test comprehension of reversible active and passive sentences, and Tense; (b) a sentence grammaticality judgement task to test judgement of Tense, Aspect, and subject-verb Agreement; and (c) a picture-pointing task to test comprehension of Complementizer Phrase.

Outcomes & Results: (a) Two of the three agrammatic participants performed at chance on reversible passive sentences and above chance on active sentences. The third participant performed equally high on the two sentence types. Two participants performed at chance on Tense comprehension and one above chance. (b) The three participants were selectively or across-the-board impaired in judgement of Agreement, Tense, and Aspect. One of the two selectively affected participants had chance performance on Aspect and above chance performance on Agreement and Tense. The other one performed at chance on Aspect and Tense, and above chance on Agreement. The third participant's performance was equally poor on all three categories. (c) All three agrammatic participants performed above chance on the comprehension of Complementizer Phrase.

Conclusions: In comprehension/judgement, canonical and non-canonical sentences do not dissociate in all agrammatic speakers, while functional categories associated with the verb morphology may be compromised in the face of relatively well-preserved categories that are located higher in the syntactic hierarchy. All three agrammatic participants support the DMA, and two of them support the TDH. Instead, none of them provided support to the TPH, TUH, and IFIH.     

Agrammatic patterns in Alzheimer's disease: Evidence from tense,agreement, and aspect

Background: Little research has been conducted on functional categories in probable Alzheimer's disease (pAD). Furthermore, the findings are contradictory, since some studies report ceiling performance on tense and/or subject–verb agreement (Kaprinis & Stavrakaki, 2007 Kaprinis, S. and Stavrakaki, S. 2007. Morphological and syntactic abilities in patients with Alzheimer's disease. Brain and Language, 103: 59–60. doi:10.1016/j.bandl.2007.07.044[Crossref], [Web of Science ®] , [Google Scholar]; Kavé & Levy, 2003 Kavé, G. and Levy, Y. 2003. Sensitivity to gender, person and tense inflection by persons with Alzheimer's disease. Brain and Language, 87: 267–277. doi:10.1016/S0093-934X(03)00106-8[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), whereas others report morphosyntactic deficits and agrammatic profiles (e.g., Altmann, Kempler, & Andersen, 2001 Altmann, L. G. P., Kempler, D. and Andersen, E. S. 2001. Speech errors in Alzheimer's disease: Reevaluating morphosyntactic preservation. Journal of Speech, Language, and Hearing Research, 44: 1069–1082. doi:10.1044/1092-4388(2001/085)[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]).

Aims: This study investigates the ability of Greek-speaking pAD individuals to produce and judge subject–verb agreement, tense, and aspect. Given pAD individuals have working memory limitations (e.g., Baddeley, 1996 Baddeley, A. 1996. Exploring the central executive. The Quarterly Journal of Experimental Psychology, 49: 5–28. doi:10.1080/713755608[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]), and given the differential processing demands of agreement, tense and aspect (e.g., Fyndanis, Varlokosta, & Tsapkini, 2012a Fyndanis, V., Varlokosta, S. and Tsapkini, K. 2012a. Agrammatic production: Interpretable features and selective impairment in verb inflection. Lingua, 122: 1134–1147. doi:10.1016/j.lingua.2012.05.004[Crossref], [Web of Science ®] , [Google Scholar]), pAD participants are expected to perform better on agreement than on tense/aspect. Based on the hypothesis that reference to the past is computationally more demanding than reference to the future/present (e.g., Bastiaanse et al., 2011 Bastiaanse, R., Bamyaci, E., Hsu, C-J., Lee, J., Yarbay Duman, T. and Thompson, C. K. 2011. Time reference in agrammatic aphasia: A cross-linguistic study. Journal of Neurolinguistics, 24: 652–673. doi:10.1016/j.jneuroling.2011.07.001[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), a within-tense dissociation is expected to emerge. Further, on the assumption that unmarked values of functional categories are less demanding than marked values (e.g., Lapointe, 1985 Lapointe, S. 1985. A theory of verb form use in the speech of agrammatic aphasics. Brain and Language, 24: 100–155. doi:10.1016/0093-934X(85)90100-2[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), the imperfective (unmarked) aspect is expected to be better preserved than the perfective (marked) aspect.

Methods & Procedures: Ten Greek-speaking mild pAD individuals and six healthy controls participated in a sentence completion task, a grammaticality judgement task, and a sentence–picture matching task. Non-parametric tests were used for analysis of results.

Outcomes & Results: PAD participants were found to be significantly more impaired in aspect compared to tense and agreement, in both production and grammaticality judgement/comprehension. Agreement was found significantly better preserved than tense in production. Similar patterns of performance have been attested in agrammatism (e.g., Fyndanis et al., 2012a Fyndanis, V., Varlokosta, S. and Tsapkini, K. 2012a. Agrammatic production: Interpretable features and selective impairment in verb inflection. Lingua, 122: 1134–1147. doi:10.1016/j.lingua.2012.05.004[Crossref], [Web of Science ®] , [Google Scholar]). Reference to the past and reference to the future did not dissociate, whereas the imperfective aspect was found to be significantly more impaired than the perfective aspect in production.

Conclusions: PAD participants' better performance on producing agreement, compared to tense/aspect, is accounted for in terms of the differential demands these categories pose on the processing system. Agreement is computationally less demanding than tense/aspect, because the former involves processing of grammatical information only, whereas the latter involve processing and integration of grammatical and extralinguistic/conceptual information. The preponderance of tense over aspect is attributed to the subjectivity of the latter, which renders it either a category “difficult” to test, or a computationally more demanding condition. The results also show that reference to the past is as demanding as reference to the future. The hypothesis that unmarked values are easier than marked ones is not supported by our data.     

Morphosyntactic production in Greek- and Italian-speaking individuals with probable Alzheimer’s disease: evidence from subject–verb agreement,tense/time reference,and mood

ABSTRACT

Background: In probable Alzheimer’s disease (AD), different memory systems, executive functioning, visuospatial recognition, and language are impaired. Regarding the latter, only a few studies have investigated morphosyntactic production thus far.

Aims: This study, which is a follow-up on Fyndanis, V., Manouilidou, C., Koufou, E., Karampekios, S., and Tsapakis, E. M. (2013). Agrammatic patterns in Alzheimer's disease: Evidence from tense, agreement, and aspect. Aphasiology, 27, 178–200. doi:10.1080/02687038.2012.705814, investigates whether verb-related morphosyntactic production is (selectively) impaired in AD focusing on two highly inflected languages, Greek and Italian. The morphosyntactic phenomena explored are subject–verb Agreement, Tense/Time Reference, and Mood. Focusing on these phenomena allows us to investigate if recent hypotheses, originally developed in aphasia research, can also capture results related to AD. We tested the hypotheses discussed in Fyndanis, V., Manouilidou, C., Koufou, E., Karampekios, S., and Tsapakis, E. M. (2013). Agrammatic patterns in Alzheimer's disease: Evidence from tense, agreement, and aspect. Aphasiology, 27, 178–200. doi:10.1080/02687038.2012.705814, that is, the Interpretable Features’ Impairment Hypothesis (IFIH) (e.g., Fyndanis, V., Varlokosta, S., & Tsapkini, K. 2012. Agrammatic production: Interpretable features and selective impairment in verb inflection. Lingua, 122, 1134–1147. doi:10.1016/j.lingua.2012.05.004) and the PAst DIscourse LInking Hypothesis (PADILIH; Bastiaanse, R., Bamyaci, E., Hsu, C., Lee, J., Yarbay Duman, T., & Thompson, C. K. 2011. Time reference in agrammatic aphasia: A cross-linguistic study. Journal of Neurolinguistics, 24, 652–673. doi:10.1016/j.jneuroling.2011.07.001).

Methods & Procedures: Two sentence completion tasks testing the production of subject–verb Agreement, Tense/Time Reference, and Mood were administered to 16 Greek-speaking and 10 Italian-speaking individuals with mild-to-moderate AD, as well as to 16 Greek-speaking and 11 Italian-speaking neurologically intact individuals who were matched with the participants with AD on age and education. Mixed-effects models were fitted to the data.

Outcomes & Results: At the group level, both the Greek and Italian participants with AD performed worse than the controls. Both AD groups revealed selective patterns of morphosyntactic production (Greek: Agreement/Mood > Time Reference; Italian: Agreement > Time Reference > Mood). Past Reference and Future Reference did not dissociate in either of the two AD groups. Nevertheless, in all four participants with AD who showed dissociations, Past Reference was more impaired than Future Reference.

Conclusions: The results indicate that the production of verb-related morphosyntactic categories can be impaired in mild-to-moderate AD. The different patterns observed in the two languages are partly attributable to the different way these languages encode Mood. The group results (of both the Greek- and Italian-speaking participants with AD) do not lend support to the PADILIH, whereas only the results of the Italian AD group are fully consistent with the IFIH. However, the individual data are consistent with the PADILIH, and the IFIH is informed by the present data and modified accordingly so that it can capture cross-linguistic patterns of morphosyntactic impairment.