Methodologies for assessing morphosyntactic ability in people with Alzheimer's disease

BACKGROUND

The detection and description of language impairments in neurodegenerative diseases like Alzheimer's Disease (AD) play an important role in research, clinical diagnosis and intervention. Various methodological protocols have been implemented for the assessment of morphosyntactic abilities in AD; narrative discourse elicitation tasks and structured experimental tasks for production, offline and online structured experimental tasks for comprehension. Very few studies implement and compare different methodological protocols; thus, little is known about the advantages and disadvantages of each methodology.

AIMS

To discuss and compare the main behavioral methodological approaches and tasks that have been used in psycholinguistic research to assess different aspects of morphosyntactic production and comprehension in individuals with AD at the word and sentence levels.

METHODS

A narrative review was conducted through searches in the scientific databases Google Scholar, Scopus, Science Direct, MITCogNet, PubMed. Only studies written in English, that reported quantitative data and were published in peer-reviewed journals were considered with respect to their methodological protocol. Moreover, we considered studies that reported research on all stages of the disease and we included only studies that also reported results of a healthy control group. Studies that implemented standardized assessment tools were not considered in this review.

OUTCOMES & RESULTS

The main narrative discourse elicitation tasks implemented for the assessment of morphosyntactic production include interviews, picture-description and story narration, whereas the main structured experimental tasks include sentence completion, constrained sentence production, sentence repetition and naming. Morphosyntactic comprehension in AD has been assessed with the use of structured experimental tasks, both offline (sentence-picture matching, grammaticality judgment) and online (cross-modal naming,speeded sentence acceptability judgment, auditory moving window, word detection, reading). For each task we considered studies that reported results from different morphosyntactic structures and phenomena in as many different languages as possible.

CONCLUSIONS & IMPLICATIONS

Our review revealed strengths and weaknesses of these methods but also directions for future research. Narrative discourse elicitation tasks as well as structured experimental tasks have been used in a variety of languages, and have uncovered preserved morphosyntactic production but also deficits in people with AD. A combination of narrative discourse elicitation and structured production tasks for the assessment of the same morphosyntactic structure has been rarely used. Regarding comprehension, offline tasks have been implemented in various languages, whereas online tasks have been mainly used in English. Offline and online experimental paradigms have often produced contradictory results even within the same study. The discrepancy between the two paradigms has been attributed to the different working memory demands they impose to the comprehender or to the different parsing processes they tap. Strengths and shortcomings of each methodology are summarized in the paper, and comparisons between different tasks are attempted when this is possible. Thus, the paper may serve as a methodological guide for the study of morphosyntax in AD and possibly in other neurodegenerative diseases.

WHAT THIS PAPER ADDS

What is already known on this subject For the assessment of morphosyntactic abilities in AD, various methodological paradigms have been implemented: narrative discourse elicitation tasks and structured experimental tasks for production, and offline and online structured experimental tasks for comprehension. Very few studies implement and compare different methodological protocols; thus, little is known about the advantages and disadvantages of each methodology. What this paper adds to existing knowledge The paper presents an overview of methodologies that have been used to assess morphosyntactic production and comprehension of people with AD at the word and sentence levels. The paper summarizes the strengths and shortcomings of each methodology, providing both the researcher and the clinician with some directions in their endeavour of investigating language in AD. Also, the paper highlights the need for further research that will implement carefully scrutinized tasks from various experimental paradigms and will explore distinct aspects of the AD patients' morphosyntactic abilities in typologically different languages. What are the potential or actual clinical implications of this work? The paper may serve as a reference point for (psycho-)linguists who wish to study morphosyntactic abilities in AD, and for speech and language therapists who might need to apply morphosyntactic protocols to their patients in order to assess them or design appropriate therapeutic interventions for production and comprehension deficits.

Applying a Parent Training Program in a Naturalistic Behavior Analytic Context to Improve Attachment in Children with ASD

Infants develop attachment to their caregivers very early on. The quality of attachment is considered to be crucial for the emotional development of humans and animals alike. Despite its importance, very little is known about how attachment develops between children with Autism Spectrum Disorder (ASD) and their caregivers. The purpose of the present study was to assess the attachment patterns of two young children with ASD with their parents and to identify the means for promoting parent, child, and parent-child relational characteristics that may contribute to the development of secure attachment. The results replicated prior findings pertaining to attachment quality of children with ASD and demonstrated the effectiveness of a naturalistic, behavior-analytic intervention in improving the quality of their attachment.

The Acquisition of Relative Clauses in Autism: The Role of Executive Functions and Language

PURPOSE

Relative clauses present a well-known processing asymmetry between object-extracted and subject-extracted dependencies across both typical and atypical populations. The present study aimed at exploring the comprehension of object and subject relative clauses as conceptualized by the Relativized Minimality framework in autistic children and in a group of age- and IQ-matched typically-developing children. The study also explored the way performance in relative clauses would be affected by the children's language and executive function skills.

METHOD

Relative clause comprehension was tested through a sentence-picture matching task and language was tested with a receptive vocabulary task. Executive functions were assessed through backward digit recall and a Flanker test.

RESULTS

Object relative clauses were harder to parse for both groups than subject relatives, while number mismatch between the moved object Noun Phrase and the intervening subject Noun Phrase in object relatives boosted both groups' performances. Typically-developing children's performance in object relatives was predicted by both language and executive functions, while autistic children failed to use language and did not systematically draw on their executive functions in object relative clause comprehension.

CONCLUSION

The findings suggest that relative clause processing in autism follows a normal developmental trajectory, and that difficulty with parsing object relative clauses stems from reduced language and executive functions rather than deficits in the children's morphosyntactic skills.

The nonverbal BriefScreen: A cognitive screening method for patients with limited language and motor abilities

Dementia and significant cognitive decline are frequent sequelae of stroke, but are difficult to evaluate when aphasia and/or motor impairment are present. The linguistic and motor requirements of commonly employed screening tests render them problematic for use post-stroke. The present study examines the validity of the Nonverbal BriefScreen, a brief screening method with limited verbal and motor requirements, in groups of patients with known cognitive impairment using the MMSE as a gold standard. Participants were 137 healthy middle aged and older community dwellers, 21 patients with MCI/early dementia and 35 patients with different types of dementia. The sensitivity and specificity of the Nonverbal BriefScreen were calculated for various cutoff scores, with the MMSE as comparison. The Nonverbal BriefScreen was effective in discriminating between healthy controls and patients with dementia, as well as between healthy controls and all patients, with areas under the ROC curve similar to that of the MMSE. ROC analyses with a smaller sample of 35 age-matched healthy controls showed adequate discriminant ability to detect cognitive impairment. The Nonverbal BriefScreen was shown to be a valid method for screening for cognitive impairment that could be employed as a screening method for patients with limited language.

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.

Comprehension asymmetries in language acquisition: a test for Relativized Minimality

Cross-linguistic studies have shown that typically developing children have difficulties comprehending non-canonical structures. These findings have been interpreted within the Relativized Minimality (RM) approach, according to which local relations cannot be established between two terms of a dependency if an intervening element possesses similar morphosyntactic features. In an extension of RM, Friedmann, Belletti, and Rizzi (2009) suggested that lexical NP restriction is the source of minimality effects in non-canonical sentences. The present study aimed at investigating whether the predictions of their account can be confirmed in Greek. Our results indicate that although lexical NP restriction is a crucial factor in generating minimality effects, it is not always sufficient to account for the comprehension difficulties that young children face with non-canonical sentences, since the internal structure (i.e. the feature specification) of the moved element and of the intervener affects their performance, as well.

Pronoun comprehension in individuals with Down syndrome: the role of age

BACKGROUND

A number of studies have suggested that language in individuals with Down syndrome (DS) may not be simply delayed compared with language in typically developing (TD) children, but deviant. The deviance has been detected in the comprehension of pronouns, and it has triggered proposals for the existence of a specific syntactic deficit in individuals with DS. However, the developmental path of pronoun comprehension in individuals with DS is unknown as there are no studies examining individuals of different ages.

AIMS

To perform a pilot study examining pronoun comprehension in adolescents and adults with DS in comparison with TD children. Research questions include: Are some pronoun types more difficult than others for each of the two groups (DS and TD)? Is there a difference in performance between the two groups? Does performance correlate with chronological age in the DS group?

METHODS & PROCEDURES

Using a manual picture selection task, we examined the comprehension of different types of pronouns in 14 Greek-speaking individuals with DS, ranging from 10 to 34 years of age. We also tested a control group of TD children as well as a typical adult group. The TD and DS groups were recruited and tested in pre-schools and schools/centres for individuals with learning disabilities, respectively. Within- and between-group comparisons were performed for all conditions. For the DS group, correlations between chronological age and performance in each condition were also explored.

OUTCOMES & RESULTS

Results reveal a significant positive correlation of age with performance in the DS group, but only in structures that also presented difficulties to TD children. Structures that presented difficulties only to individuals with DS do not appear to be less problematic for older participants.

CONCLUSIONS & IMPLICATIONS

These findings provide support to the deviance hypothesis by suggesting that the syntactic deficit in the comprehension of pronouns in individuals with DS is present in individuals of a wide age range. At the same time, the results, if corroborated by large-scale studies, suggest that some aspects of grammatical development in individuals with DS may continue even after adolescence and well into adulthood. We argue that these findings can contribute towards more targeted intervention practices by increasing our knowledge of the behavioural phenotype of DS.

Pronoun comprehension in individuals with down syndrome: deviance or delay?

PURPOSE

Results of recent pilot studies suggest that the interpretation of pronouns in individuals with Down syndrome (DS) may follow a pattern unattested in typical development, indicating the presence of a selective deficit targeting the comprehension of reflexive pronouns. These findings come at a time when there is a heated debate surrounding pronoun comprehension in typical development as well. This study aims to contribute to these debates by examining pronoun comprehension in Greek, a language that exhibits unusual patterns in pronoun comprehension in typical development.

METHOD

Seven Greek-speaking individuals with DS and a control group of 14 typically developing (TD) children were tested. The authors examined the comprehension of strong pronouns, reflexive pronouns, and pronominal clitics, using a picture selection task.

RESULTS

The data reveal evidence of deviant pronoun comprehension in individuals with DS compared with the TD group. The DS group encountered problems in the interpretation of reflexive pronouns when compared with the TD group, while the performance of the two groups was comparable in all remaining conditions.

CONCLUSIONS

Findings are in line with the selective deficit model of language comprehension in DS, supporting the presence of a cross-linguistic reflexive deficit.

Patterns of syntactic development in children with Williams syndrome and Down's syndrome: evidence from passives and wh-questions

This study investigates the syntactic abilities of ten individuals with Williams syndrome (WS) (mean chronological age: 8;9 years; mean mental age: 4;8 years) and Down's syndrome (DS) (mean chronological age: 8;7 years; mean mental age: 4;6 years), matched individually on chronological age, mental age and performance IQ. The syntactic components investigated include the comprehension of passives and the production, comprehension and repetition of wh-questions. Performance is compared to ten younger typically developing (TD) controls matched individually to both experimental groups on mental age (mean chronological age: 4;4 years; mean mental age: 5;0 years). Participants were given a standardized measure of grammatical ability and non-standardized tasks exploring the comprehension of active and passive sentences, and the production, comprehension and repetition of a range of wh-question types: wh-subject, wh-object, which NP-subject and which NP-object. Participants with WS and DS performed similarly on the standardized measure of grammatical ability, as well as on the experimental tasks that tapped comprehension of passives, and production and comprehension of wh-questions. Participants with DS performed significantly more poorly than both the WS cohort and TD controls on the repetition of wh-questions. Both the WS and DS cohorts performed significantly more poorly on most of the syntactic tasks compared to the younger TD controls. Individuals with WS and DS experienced significant difficulties in tasks measuring aspects of syntactic ability and performed more poorly than mental age-matched TD controls. Implications of these findings, with regards to the debates around language "intactness" in WS, as well as the similarities and differences in language abilities in WS and DS, dependent on age and developmental stages studied, are explored.