On the preservation of syntax in Alzheimer's disease. Evidence from written sentences

Language Markers of Dementia and Their Role in Early Diagnosis of Alzheimer's Disease: Exploring Grammatical and Syntactic Competence via Sentence Repetition

Background

Earlier research focuses primarily on the cognitive changes due to Alzheimer's disease (AD); however, little is known with regard to changes in language competence across the lifespan.

Objective

The present study aims to investigate the decline of language skills at the grammatical and syntactic levels due to changes in cognitive function.

Methods

We administered the Litmus Sentence Repetition Task (SRT) to 150 native speakers of Greek who fall into five groups: 1) young healthy speakers, 2) cognitively intact elder healthy speakers, 3) speakers with subjective cognitive impairment (SCI), 4) speakers with mild cognitive impairment (MCI); and 5) speakers with AD dementia at the mild/moderate stages. All participants underwent a physical and neurological examination and cognitive screening with a standardized neuropsychological battery to assess cognitive status comprehensively and evaluate aspects like working memory, executive function, attention and memory to appropriately classify them.

Results

The data analysis revealed that the SRT had high discriminatory value in the development of AD; specifically, both accuracy and grammaticality indices were related to cognitive decline. Additionally, syntax significantly affected the performance of speakers with structures such as clitics being particularly challenging and in most structures the performance of speakers with MCI drops significantly compared to speakers with SCI.

Conclusions

Linguistic indices revealed subtle early signs of cognitive decline that can be helpful in the early detection of AD, thus facilitating the clinical process offering support to language-based assessment tools such as sentence repetition, a non-invasive type of assessment to evaluate symptoms of AD.

Disintegration at the Syntax-Semantics Interface in Prodromal Alzheimer's Disease: New Evidence from Complex Sentence Anaphora in Amnestic Mild Cognitive Impairment (aMCI)

Although diverse language deficits have been widely observed in prodromal Alzheimer's disease (AD), the underlying nature of such deficits and their explanation remains opaque. Consequently, both clinical applications and brain-language models are not well-defined. In this paper we report results from two experiments which test language production in a group of individuals with amnestic Mild Cognitive Impairment (aMCI) in contrast to healthy aging and healthy young. The experiments apply factorial designs informed by linguistic analysis to test two forms of complex sentences involving anaphora (relations between pronouns and their antecedents). Results show that aMCI individuals differentiate forms of anaphora depending on sentence structure, with selective impairment of sentences which involve construal with reference to context (anaphoric coreference). We argue that aMCI individuals maintain core structural knowledge while evidencing deficiency in syntax-semantics integration, thus locating the source of the deficit in the language-thought interface of the Language Faculty.

Automated Measures of Syntactic Complexity in Natural Speech Production: Older and Younger Adults as a Case Study

PURPOSE

Multiple methods have been suggested for quantifying syntactic complexity in speech. We compared eight automated syntactic complexity metrics to determine which best captured verified syntactic differences between old and young adults.

METHOD

We used natural speech samples produced in a picture description task by younger (n = 76, ages 18-22 years) and older (n = 36, ages 53-89 years) healthy participants, manually transcribed and segmented into sentences. We manually verified that older participants produced fewer complex structures. We developed a metric of syntactic complexity using automatically extracted syntactic structures as features in a multidimensional metric. We compared our metric to seven other metrics: Yngve score, Frazier score, Frazier-Roark score, developmental level, syntactic frequency, mean dependency distance, and sentence length. We examined the success of each metric in identifying the age group using logistic regression models. We repeated the analysis with automatic transcription and segmentation using an automatic speech recognition (ASR) system.

RESULTS

Our multidimensional metric was successful in predicting age group (area under the curve [AUC] = 0.87), and it performed better than the other metrics. High AUCs were also achieved by the Yngve score (0.84) and sentence length (0.84). However, in a fully automated pipeline with ASR, the performance of these two metrics dropped (to 0.73 and 0.46, respectively), while the performance of the multidimensional metric remained relatively high (0.81).

CONCLUSIONS

Syntactic complexity in spontaneous speech can be quantified by directly assessing syntactic structures and considering them in a multivariable manner. It can be derived automatically, saving considerable time and effort compared to manually analyzing large-scale corpora, while maintaining high face validity and robustness.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24964179.

Handwriting Markers for the Onset of Alzheimer's Disease

INTRODUCTION

Alzheimer's disease has an impact on handwriting (AD). Numerous researchers reported that fact. Therefore, examining handwriting characteristics could be a useful way to screen for AD. The aim of the article is to present the reliability and effectiveness of the AD-HS tool.

METHODS

Most of the existing studies examine either linguistic manifestations of writing or certain motor functions. However, handwriting is a complex of cognitive and motor activities. Since the influence of AD on handwriting is individual, it is important to analyze the complete set of handwriting features. The AD-HS instrument is based on this principle. Validation of the AD-HS instrument for revealing cognitive impairment in AD-diagnosed persons in comparison to the control group. The study is based on the evaluation of free handwritten texts. AD-HS includes 40 handwriting and 2 linguistic features of handwritten texts. It is based on the standard protocol for handwriting analysis. The cumulative evaluation of all features builds a quantitative AD-Indicator (ADI) as a marker of possible AD conditions. The analyzed experiment includes 53 AD-diagnosed persons and a control group of 192 handwriting specimens from the existing database.

RESULTS

AD-HS shows a distinct difference in evaluated ADI for the participants (the mean value equals 0.49) and the control group (the mean value equals 0.28).

CONCLUSION

The handwriting marker of AD could be an effective supplement instrument for earlier screening. It is also useful when traditional biomarkers and neurological tests could not be applied. AD-HS can accompany therapy as an indication of its effect on a person.

Handwriting Changes in Alzheimer's Disease: A Systematic Review

BACKGROUND

Handwriting is a complex process involving fine motor skills, kinesthetic components, and several cognitive domains, often impaired by Alzheimer's disease (AD).

OBJECTIVE

Provide a systematic review of handwriting changes in AD, highlighting the effects on motor, visuospatial and linguistic features, and to identify new research topics.

METHODS

A search was conducted on PubMed, Scopus, and Web of Science to identify studies on AD and handwriting. The review followed PRISMA norms and analyzed 91 articles after screening and final selection.

RESULTS

Handwriting is impaired at all levels of the motor-cognitive hierarchy in AD, particularly in text, with higher preservation of signatures. Visuospatial and linguistic features were more affected. Established findings for motor features included higher variability in AD signatures, higher in-air/on-surface time ratio and longer duration in text, longer start time/reaction time, and lower fluency. There were conflicting findings for pressure and velocity in motor features, as well as size, legibility, and pen lifts in general features. For linguistic features, findings were contradictory for error patterns, as well as the association between agraphia and severity of cognitive deficits.

CONCLUSIONS

Further re-evaluation studies are needed to clarify the divergent results on motor, general, and linguistic features. There is also a lack of research on the influence of AD on signatures and the effect of AD variants on handwriting. Such research would have an impact on clinical management (e.g., for early detection and patient follow-up using handwriting tasks), or forensic examination aimed at signatory identification.

Investigating sentence processing and working memory in patients with mild Alzheimer and elderly people

INTRODUCTION

Linguistic disorders are one of the common problems in Alzheimer's disease, which in recent years has been considered as one of the key parameters in the diagnosis of Alzheimer (AD). Given that changes in sentence processing and working memory and the relationship between these two activities may be a diagnostic parameter in the early and preclinical stages of AD, the present study examines the comprehension and production of sentences and working memory in AD patients and healthy aged people.

METHODS

Twenty-five people with mild Alzheimer's and 25 healthy elderly people participated in the study. In this study, we used the digit span to evaluate working memory. Syntactic priming and sentence completion tasks in canonical and non-canonical conditions were used for evaluating sentence production. We administered sentence picture matching and cross-modal naming tasks to assess sentence comprehension.

RESULTS

The results of the present study revealed that healthy elderly people and patients with mild Alzheimer's disease have a significant difference in comprehension of relative clause sentences (P <0.05). There was no significant difference between the two groups in comprehension of simple active, simple active with noun phrase and passive sentences (P> 0.05). They had a significant difference in auditory and visual reaction time (P <0.05). Also there was a significant difference between the two groups in syntactic priming and sentence completion tasks. However, in non-canonical condition of sentence completion, the difference between the two groups was not significant (P> 0.05).

CONCLUSION

The results of the present study showed that the mean scores related to comprehension, production and working memory in people with mild Alzheimer's were lower than healthy aged people, which indicate sentence processing problems at this level of the disease. People with Alzheimer have difficulty comprehending and producing complex syntactic structures and have poorer performance in tasks that required more memory demands. It seems that the processing problems of these people are due to both working memory and language problems, which are not separate from each other and both are involved in.

The functional connectivity of language network across the life span: Disentangling the effects of typical aging from Alzheimer's disease

Language is usually characterized as the most preserved cognitive function during typical aging. Several neuroimaging studies have shown that healthy aging is characterized by inter-network compensation which correlates with better language performance. On the contrary, language deficits occur early in the course of Alzheimer's disease (AD). Therefore, this study compares young participants, healthy older participants, and prodromal AD participants, to characterize functional connectivity changes in language due to healthy aging or prodromal AD. We first compared measures of integrated local correlations (ILCs) and fractional amplitude of low-frequency oscillations (fALFFs) in language areas. We showed that both groups of older adults had lower connectivity values within frontal language-related areas. In the healthy older group, higher integrated local correlation (ILC) and fALFF values in frontal areas were positively correlated with fluency and naming tasks. We then performed seed-based analyses for more precise discrimination between healthy aging and prodromal AD. Healthy older adults showed no functional alterations at a seed-based level when the seed area was not or only slightly impaired compared to the young adults [i.e., inferior frontal gyrus (IFG)], while prodromal AD participants also showed decreased connectivity at a seed-based level. On the contrary, when the seed area was similarly impaired in healthy older adults and prodromal AD participants on ILC and fALFF measures, their connectivity maps were also similar during seed-to-voxel analyses [i.e., superior frontal gyrus (SFG)]. Current results show that functional connectivity measures at a voxel level (ILC and fALFF) are already impacted in healthy aging. These findings imply that the functional compensations observed in healthy aging depend on the functional integrity of brain areas at a voxel level.

Automated analysis of propositional idea density in older adults

Previous research suggests oral and written language can act as barometers of an individual's cognitive function, potentially providing a screening tool for the earliest stages of Alzheimer's disease (AD) and other forms of dementia. Idea density is a measure of the rate at which ideas, or elementary predications, are expressed and may provide an ideal measure for early detection of deficits in language. Previous research has shown that when no restrictions are set on the topic of the idea, a decrease in propositional idea density (PID) is associated with an increased risk of developing AD. However, this has been limited by moderate sample sizes and manual transcribing. Technological advancement has enabled the automated calculation of PID from tools such as the Computerized Propositional Idea Density Rater (CPIDR). We delivered an online autobiographical writing task to older adult Australians from ISLAND (Island Study Linking Ageing and Neurodegenerative Disease). Linear regression models were fitted in R. We analysed text files (range 10-1180 words) using CPIDRv5 provided by 3316 (n = 853 males [25.7%], n = 2463 females [74.3%]) ISLAND participants. Over 358,957 words written in 3316 written autobiographical responses were analysed. Mean PID was higher in females (53.5 [±3.69]) than males (52.6 [±4.50]). Both advancing age and being male were significantly associated with a decrease in PID (p < .001). Automated methods of language analysis hold great promise for the early detection of subtle deficits in language capacity. Although our effect sizes were small, PID may be a sensitive measure of deficits in language in ageing individuals and is able to be collected at scale using online methods of data capture.

Language Decline Characterizes Amnestic Mild Cognitive Impairment Independent of Cognitive Decline

Purpose This research investigated the nature of cognitive decline in prodromal Alzheimer's disease (AD), particularly in mild cognitive impairment, amnestic type (aMCI). We assessed language in aMCI as compared with healthy aging (HA) and healthy young (HY) with new psycholinguistic assessment of complex sentences, and we tested the degree to which deficits on this language measure relate to performance in other general cognitive domains such as memory. Method Sixty-one individuals with aMCI were compared with 24 HA and 10 HY adults on a psycholinguistic measure of complex sentence production (relative clauses). In addition, HA, HY, and a subset of the aMCI participants (n = 22) were also tested on a multidomain cognitive screen, the Addenbrooke's Cognitive Examination-Revised (ACE-R), and on a verbal working memory Brown-Peterson (BP) test. General and generalized linear mixed models were used to test psycholinguistic results and to test whether ACE-R and BP performance predicted performance on the psycholinguistic test similarly in the aMCI and HA groups. Results On the psycholinguistic measure, sentence imitation was significantly deficited in aMCI in comparison with that in HA and HY. Experimental factorial designs revealed that individuals with aMCI had particular difficulty repeating sentences that especially challenged syntax-semantics integration. As expected, the aMCI group also performed significantly below the HY and HA groups on the ACE-R. Neither the ACE-R Memory subtest nor the BP total scores predicted performance on the psycholinguistic task for either the aMCI or the HA group. However, the ACE-R total score significantly predicted psycholinguistic task performance, with increased ACE-R performance predicting increased psycholinguistic task performance only for the HA group, not for the aMCI group. Conclusions Results suggest a selective deterioration in language in aMCI, specifically a weakening of syntax-semantics integration in complex sentence processing, and a general independence of this language deficit and memory decline. Results cohere with previous assessments of the nature of difficulty in complex sentence formation in aMCI. We argue that clinical screening for prodromal AD can be strengthened by supplementary testing of language, as well as memory, and extended evaluation of strength of their relation.

Tablet-Based Automatic Assessment for Early Detection of Alzheimer's Disease Using Speech Responses to Daily Life Questions

Health-monitoring technologies for automatically detecting the early signs of Alzheimer's disease (AD) have become increasingly important. Speech responses to neuropsychological tasks have been used for quantifying changes resulting from AD and differentiating AD and mild cognitive impairment (MCI) from cognitively normal (CN). However, whether and how other types of speech tasks with less burden on older adults could be used for detecting early signs of AD remains unexplored. In this study, we developed a tablet-based application and compared speech responses to daily life questions with those to neuropsychological tasks in terms of differentiating MCI from CN. We found that in daily life questions, around 80% of speech features showing significant differences between CN and MCI overlapped those showing significant differences in both our study and other studies using neuropsychological tasks, but the number of significantly different features as well as their effect sizes from life questions decreased compared with those from neuropsychological tasks. On the other hand, the results of classification models for detecting MCI by using the speech features showed that daily life questions could achieve high accuracy, i.e., 86.4%, comparable to neuropsychological tasks by using eight questions against all five neuropsychological tasks. Our results indicate that, while daily life questions may elicit weaker but statistically discernable differences in speech responses resulting from MCI than neuropsychological tasks, combining them could be useful for detecting MCI with comparable performance to using neuropsychological tasks, which could help develop health-monitoring technologies for early detection of AD in a less burdensome manner.

Using Automatic Assessment of Speech Production to Predict Current and Future Cognitive Function in Older Adults

Neurodegenerative conditions like Alzheimer disease affect millions and have no known cure, making early detection important. In addition to memory impairments, dementia causes substantial changes in speech production, particularly lexical-semantic characteristics. Existing clinical tools for detecting change often require considerable expertise or time, and efficient methods for identifying persons at risk are needed. This study examined whether early stages of cognitive decline can be identified using an automated calculation of lexical-semantic features of participants' spontaneous speech. Unimpaired or mildly impaired older adults (N = 39, mean 81 years old) produced several monologues (picture descriptions and expository descriptions) and completed a neuropsychological battery, including the Modified Mini-Mental State Exam. Most participants (N = 30) returned one year later for follow-up. Lexical-semantic features of participants' speech (particularly lexical frequency) were significantly correlated with cognitive status at the same visit and also with cognitive status one year in the future. Thus, automated analysis of speech production is closely associated with current and future cognitive test performance and could provide a novel, scalable method for longitudinal tracking of cognitive health.

Preliminary assessment of connected speech and language as marker for cognitive change in late middle-aged Black/African American adults at risk for Alzheimer's disease

Background

Connected speech-language (CSL) has been a promising measure of assessing cognitive decline in populations at-risk for Alzheimer's disease and related dementias (ADRD) populations. A common way to obtain CSL is through using picture description tasks such as the most frequently used image Cookie Theft (CT). However, questions have been raised about using CT for diverse communities. Little is known about the CSL produced in response to this task in Black/African American (BAA) adults aged 48-74.

Goals

The present study's goals were to characterize CSL in BAA adults by sex and APOE-ε4 status from Milwaukee in the Wisconsin Registry for Alzheimer's Prevention (WRAP) study when presented with the CT picture description task and to identify differences in CSL output between BAAs and non-Hispanic Whites (NHW).

Methods and Procedures

We collected CSL samples from the CT picture from 48 BAA participants and 30 NHW participants from the WRAP participants in Milwaukee, WI group. CSL was analyzed using chi-square tests, T-tests, and ANCOVA. Linear mixed effect regression models were used to determine the association between cognitive status and longitudinal CSL in BAA participants with more than 1 timepoint.

Outcomes and Results

Declines in CSL of BAA participants were associated with subtle declines in cognition. Among BAA participants, we found no significant differences in speech measures in terms of sex and APOE-ε4 status. Our results showed no significant differences in speech measures between BAA and NHW groups.

Conclusions

CSL analysis provides an inexpensive way to evaluate preclinical changes in cognitive status that may not be as affected by other factors, such as ethnocultural background. Future studies with larger sample sizes and participants from other geographic locations can clarify these findings.

"More than words" - Longitudinal linguistic changes in the works of a writer diagnosed with semantic dementia

Leveraging recent advances in automated language analysis and anovel statistical approach utilizing an independent control group, we explored changes in lexical output across two published works of a man diagnosed with semantic dementia. We found significant increase in adverb usage and decline in familiarity, meaningfulness, age of acquisition and co-occurrence probability over 2 years. Collectively, these indices suggest that WR's narrative structure became progressively simpler, lexically less sophisticated, and that words commonly associated together no longer appeared in close proximity. Our study illustrates how degeneration of the semantic knowledge base impacts the production, content, and quality of literary works.

Language Network Connectivity Increases in Early Alzheimer's Disease

Background:

Language production deficits occur early in the course of Alzheimer’s disease (AD); however, only a few studies have focused on language network’s functional connectivity in mild cognitive impairment (MCI) due to AD.

Objective:

The current study aims to uncover the extent of language alteration at the MCI stage, at a behavioral and neural level, using univariate and multivariate analyses of structural MRI and resting-state fMRI.

Methods:

Twenty-four MCI due to AD participants and 24 matched healthy controls underwent a comprehensive language evaluation, a structural T1-3D MRI, and resting-state fMRI. We performed seed-based analyses, using the left inferior frontal gyrus and left posterior temporal gyrus as seeds. Then, we analyzed connectivity between executive control networks and language network in each group. Finally, we used multivariate pattern analyses to test whether the two groups could be distinguished based on the pattern of atrophy within the language network; within the executive control networks, as well as the pattern of functional connectivity within the language network and within the executive control networks.

Results:

MCI due to AD participants had language impairment during standardized language tasks and connected-speech production. Regarding functional connectivity, univariate analyses were not able to discriminate participants, while multivariate pattern analyses could significantly predict participants’ group. Language network’s functional connectivity could discriminate MCI due to AD participants better than executive control networks. Most notably, they revealed an increased connectivity at the MCI stage, positively correlated with language performance.

Conclusion:

Multivariate analyses represent a useful tool for investigating the functional and structural (re-)organization of the neural bases of language.

Using a Discourse Task to Explore Semantic Ability in Persons With Cognitive Impairment

This paper uses a discourse task to explore aspects of semantic production in persons with various degree of cognitive impairment and healthy controls. The purpose of the study was to test if an in-depth semantic analysis of a cognitive-linguistic challenging discourse task could differentiate persons with a cognitive decline from those with a stable cognitive impairment. Both quantitative measures of semantic ability, using tests of oral lexical retrieval, and qualitative analysis of a narrative were used to detect semantic difficulties. Besides group comparisons a classification experiment was performed to investigate if the discourse features could be used to improve classification of the participants who had a stable cognitive impairment from those who had cognitively declined. In sum, both types of assessment methods captured difficulties between the groups, but tests of oral lexical retrieval most successfully differentiated between the cognitively stable and the cognitively declined group. Discourse features improved classification accuracy and the best combination of features discriminated between participants with a stable cognitive impairment and those who had cognitively declined with an area under the curve (AUC) of 0.93.

Voice quality and speech fluency distinguish individuals with Mild Cognitive Impairment from Healthy Controls

Mild Cognitive Impairment (MCI) is a syndrome characterized by cognitive decline greater than expected for an individual's age and education level. This study aims to determine whether voice quality and speech fluency distinguish patients with MCI from healthy individuals to improve diagnosis of patients with MCI. We analyzed recordings of the Cookie Theft picture description task produced by 26 patients with MCI and 29 healthy controls from Sweden and calculated measures of voice quality and speech fluency. The results show that patients with MCI differ significantly from HC with respect to acoustic aspects of voice quality, namely H1-A3, cepstral peak prominence, center of gravity, and shimmer; and speech fluency, namely articulation rate and averaged speaking time. The method proposed along with the obtainability of connected speech productions can enable quick and easy analysis of speech fluency and voice quality, providing accessible and objective diagnostic markers of patients with MCI.

Episodic memory decline is associated with deficits in coherence of discourse

This study investigates coherence of discourse in the production of autobiographical narratives by individuals with aMCI. Autobiographical interviews were analyzed to determine whether reduced episodic recall was related to deficits in discourse coherence. A coherence rating scale was used to evaluate relatedness of the autobiographical details produced by participants to the topic of discourse. Interviews were transcribed, segmented into details, and divided into sets of episodic, semantic, or supplementary information, which were subsequently analysed with the coherence rating scale. We predicted that the known episodic deficits observed in aMCI could also affect the retrieval of coherent episodic information. The results revealed deficits in coherence could be found in both episodic and semantic information in the aMCI group. These results suggest that the cognitive deficits experienced by individuals with aMCI may go beyond their known difficulty in recalling episodic details, as they also affect the controlled retrieval of both episodic and semantic information.

Intact reversed language-dominance but exaggerated cognate effects in reading aloud of language switches in bilingual Alzheimer's disease

OBJECTIVE

The current study investigated how Alzheimer's disease (AD) affects production of speech errors in reading-aloud of mixed-language passages with language switches on cognates (e.g., family/familia), noncognates (e.g., people/gente), and function words (the/la).

METHOD

Twelve Spanish-English bilinguals with AD and 22 controls read-aloud 8 paragraphs in 4 conditions: (a) English-default content switches, (b) English-default function switches, (c) Spanish-default content switches, and (d) Spanish-default function switches.

RESULTS

Reading elicited language intrusions (e.g., saying la instead of the), and several types of within-language errors (e.g., saying their instead of the). Reversed language-dominance effects were intact in AD; both patients and controls produced many intrusions on dominant language targets, and relatively fewer intrusions on nondominant language targets. The opposite held for within-language errors, which were more common with nondominant than dominant targets. Patients produced the most intrusion errors with cognate switch words (which best distinguished patients from controls in ROC curves of all speech error types), while controls had equal difficulty switching on cognate and function word targets.

CONCLUSIONS

Reversed language-dominance effects appear to illustrate automatic inhibitory control over the dominant language, but could instead reflect limited resources available for monitoring when completing a task in the nondominant language. The greater sensitivity of intrusion errors with cognate than with function word targets for distinguishing patients from controls implies that language control may be aided by relatively intact knowledge of grammatical constraints over code-switching in bilinguals with AD. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Connected Speech Features from Picture Description in Alzheimer's Disease: A Systematic Review

The language changes that occur over the course of Alzheimer's disease (AD) can impact communication abilities and have profound functional consequences. Picture description tasks can be used to approximate everyday communication abilities of AD patients. As various methods and variables have been studied over the years, current knowledge about the most affected features of AD discourse in the context of picture descriptions is difficult to summarize. This systematic review aims to provide researchers with an overview of the most common areas of impairment in AD discourse as they appear in picture description tasks. Based on the 44 articles fulfilling inclusion criteria, our findings reflect a multidimensional pattern of changes in the production (speech rate), syntactic (length of utterance), lexical (word-frequency and use of pronouns), fluency (repetitions and word-finding difficulties), semantic (information units), and discourse (efficiency) domains. We discuss our findings in the light of current research and point to potential scientific and clinical uses of picture description tasks in the context of AD.

Discourse macrolinguistic impairment as a marker of linguistic and extralinguistic functions decline in early Alzheimer's disease

BACKGROUND

Alzheimer's disease is characterized by macrolinguistic changes. This decline is often analyzed with quantitative scales.

AIMS

To analyze discourse production in early Alzheimer's disease (AD) and to identify qualitative markers of macrolinguistic decline.

METHODS & PROCEDURES

We analyzed macrolinguistic features of a clinical narrative task along with patients' cognitive changes. To do so, 17 early AD participants and 17 healthy controls were recruited and given a full neuropsychological and language assessment. Narrative discourses produced during the language assessment were transcribed and macrolinguistic features were qualitatively analyzed (i.e., local and global coherence marks and discourse informativeness). Inter-group comparison was complemented by intra-group correlation. As some inter-group comparisons revealed the existence of subgroups of patients, permutation tests were used to investigate how these subgroups differed vis-à-vis cognitive measures.

OUTCOMES & RESULTS

Overall, the results indicate that AD participants presented declines in informativeness and global coherence, correlated with declines in memory and executive functions. Permutation tests showed that participants with AD producing referential errors or misinterpretations had a deeper lexical-executive decline and a lower Mini-Mental State Evaluation (MMSE).

CONCLUSIONS & IMPLICATIONS

This study shows that two clinically relevant, qualitative signs differ in discourse production between typical ageing and early AD, namely information units and modalizing discourse. It also shows that macrolinguistic assessment is a useful tool for revealing impaired communication and cognition in early AD. Although lexical processing decline probably contributes to patients' macrolinguistic impairment, implications of extralinguistic functioning should be further investigated.

Language in Amnestic Mild Cognitive Impairment and Dementia of Alzheimer’s Type: Quantitatively or Qualitatively Different?

Background/Aims: The purpose of this study was to explore language differences between individuals diagnosed with amnestic mild cognitive impairment multiple domain (aMCIm) and those with probable Alzheimer’s disease, with a goal of (i) characterizing the language profile of aMCIm and (ii) determining whether the profiles of dementia of Alzheimer’s type (DAT) and aMCIm individuals are on a continuum of one diagnostic entity or represent two distinct ­cognitive disorders. Methods: Language data from 28 patients with consensus diagnosis of aMCIm and DAT derived from a retrospective chart review were compared to that of healthy controls. Results: A non-parametric statistic established that there was no significant difference between groups in age, years of education or duration of symptoms and that expressive language was found to be relatively intact in both patient groups. In contrast, both groups exhibited significant impairments on receptive language tests and on linguistically complex tasks that rely on episodic memory and executive functions. Individuals with aMCIm and DAT present with configurations of language features that are largely in parallel to each other and reflect predominantly quantitative differences. Conclusion: Language tests provide an important contribution to the diagnostic process in their capacity to identify language impairments at an early stage. Understanding the nature of language decline is critically important to the intervention process as this information would inform cognitive intervention approaches aimed at promoting quality of life in people living with MCI and dementia.

Identification of Mild Cognitive Impairment From Speech in Swedish Using Deep Sequential Neural Networks

While people with mild cognitive impairment (MCI) portray noticeably incipient memory difficulty in remembering events and situations along with problems in decision making, planning, and finding their way in familiar environments, detailed neuropsychological assessments also indicate deficits in language performance. To this day, there is no cure for dementia but early-stage treatment can delay the progression of MCI; thus, the development of valid tools for identifying early cognitive changes is of great importance. In this study, we provide an automated machine learning method, using Deep Neural Network Architectures, that aims to identify MCI. Speech materials were obtained using a reading task during evaluation sessions, as part of the Gothenburg MCI research study. Measures of vowel duration, vowel formants (F1 to F5), and fundamental frequency were calculated from speech signals. To learn the acoustic characteristics associated with MCI vs. healthy controls, we have trained and evaluated ten Deep Neural Network Architectures and measured how accurately they can diagnose participants that are unknown to the model. We evaluated the models using two evaluation tasks: a 5-fold crossvalidation and by splitting the data into 90% training and 10% evaluation set. The findings suggest first, that the acoustic features provide significant information for the identification of MCI; second, the best Deep Neural Network Architectures can classify MCI and healthy controls with high classification accuracy (M = 83%); and third, the model has the potential to offer higher accuracy than 84% if trained with more data (cf., SD≈15%). The Deep Neural Network Architecture proposed here constitutes a method that contributes to the early diagnosis of cognitive decline, quantify the progression of the condition, and enable suitable therapeutics.

Computer-based evaluation of Alzheimer's disease and mild cognitive impairment patients during a picture description task

Introduction

We present a methodology to automatically evaluate the performance of patients during picture description tasks.

Methods

Transcriptions and audio recordings of the Cookie Theft picture description task were used. With 25 healthy elderly control (HC) samples and an information coverage measure, we automatically generated a population-specific referent. We then assessed 517 transcriptions (257 Alzheimer's disease [AD], 217 HC, and 43 mild cognitively impaired samples) according to their informativeness and pertinence against this referent. We extracted linguistic and phonetic metrics which previous literature correlated to early-stage AD. We trained two learners to distinguish HCs from cognitively impaired individuals.

Results

Our measures significantly (P < .001) correlated with the severity of the cognitive impairment and the Mini–Mental State Examination score. The classification sensitivity was 81% (area under the curve of receiver operating characteristics = 0.79) and 85% (area under the curve of receiver operating characteristics = 0.76) between HCs and AD and between HCs and AD and mild cognitively impaired, respectively.

Discussion

An automated assessment of a picture description task could assist clinicians in the detection of early signs of cognitive impairment and AD.

Connected Language in Late Middle-Aged Adults at Risk for Alzheimer's Disease

Connected language is often impaired among people with Alzheimer's disease (AD), yet little is known about when language difficulties first emerge on the path to a clinical diagnosis. The objective of this study was to determine whether individuals with psychometric (preclinical) evidence of amnestic mild cognitive impairment (pMCI) showed deficits in connected language measures. Participants were 39 pMCI and 39 cognitively healthy (CH) adults drawn from the Wisconsin Registry for Alzheimer's Prevention, who were matched for age, literacy, and sex. Participants completed a connected language task in which they described the Cookie Theft picture from the Boston Diagnostic Aphasia Examination. Language samples were analyzed across three language domains: content, syntactic complexity, and speech fluency. Paired t-tests were used to compare CH and pMCI groups on all variables, and Cohen's d effect sizes were calculated for each comparison. The CH and pMCI groups differed significantly on measures of content (e.g., CH group produced more semantic units, more unique words and had larger idea density, on average, than the pMCI group). The picture description findings are consistent with previous retrospective studies showing semantic language differences in adults with autopsy-confirmed AD. Given that these comparisons are between cognitively healthy and pMCI individuals (before a clinical MCI diagnosis), these findings may represent subtle language difficulty in spontaneous speech, and may be predictive of larger language changes over time.

Internet Searches and Their Relationship to Cognitive Function in Older Adults: Cross-Sectional Analysis

BACKGROUND

Alzheimer disease (AD) is a very challenging experience for all those affected. Unfortunately, detection of Alzheimer disease in its early stages when clinical treatments may be most effective is challenging, as the clinical evaluations are time-consuming and costly. Recent studies have demonstrated a close relationship between cognitive function and everyday behavior, an avenue of research that holds great promise for the early detection of cognitive decline. One area of behavior that changes with cognitive decline is language use. Multiple groups have demonstrated a close relationship between cognitive function and vocabulary size, verbal fluency, and semantic ability, using conventional in-person cognitive testing. An alternative to this approach which is inherently ecologically valid may be to take advantage of automated computer monitoring software to continually capture and analyze language use while on the computer.

OBJECTIVE

The aim of this study was to understand the relationship between Internet searches as a measure of language and cognitive function in older adults. We hypothesize that individuals with poorer cognitive function will search using fewer unique terms, employ shorter words, and use less obscure words in their searches.

METHODS

Computer monitoring software (WorkTime, Nestersoft Inc) was used to continuously track the terms people entered while conducting searches in Google, Yahoo, Bing, and Ask.com. For all searches, punctuation, accents, and non-ASCII characters were removed, and the resulting search terms were spell-checked before any analysis. Cognitive function was evaluated as a z-normalized summary score capturing five unique cognitive domains. Linear regression was used to determine the relationship between cognitive function and Internet searches by controlling for variables such as age, sex, and education.

RESULTS

Over a 6-month monitoring period, 42 participants (mean age 81 years [SD 10.5], 83% [35/42] female) conducted 2915 searches using these top search engines. Participants averaged 3.08 words per search (SD 1.6) and 5.77 letters per word (SD 2.2). Individuals with higher cognitive function used more unique terms per search (beta=.39, P=.002) and employed less common terms in their searches (beta=1.39, P=.02). Cognitive function was not significantly associated with the length of the words used in the searches.

CONCLUSIONS

These results suggest that early decline in cognitive function may be detected from the terms people search for when they use the Internet. By continuously tracking basic aspects of Internet search terms, it may be possible to detect cognitive decline earlier than currently possible, thereby enabling proactive treatment and intervention.

Predicting mild cognitive impairment from spontaneous spoken utterances

INTRODUCTION

Trials in Alzheimer's disease are increasingly focusing on prevention in asymptomatic individuals. We hypothesized that indicators of mild cognitive impairment (MCI) may be present in the content of spoken language in older adults and be useful in distinguishing those with MCI from those who are cognitively intact. To test this hypothesis, we performed linguistic analyses of spoken words in participants with MCI and those with intact cognition participating in a clinical trial.

METHODS

Data came from a randomized controlled behavioral clinical trial to examine the effect of unstructured conversation on cognitive function among older adults with either normal cognition or MCI (ClinicalTrials.gov: NCT01571427). Unstructured conversations (but with standardized preselected topics across subjects) were recorded between interviewers and interviewees during the intervention sessions of the trial from 14 MCI and 27 cognitively intact participants. From the transcription of interviewees recordings, we grouped spoken words using Linguistic Inquiry and Word Count (LIWC), a structured table of words, which categorizes 2500 words into 68 different word subcategories such as positive and negative words, fillers, and physical states. The number of words in each LIWC word subcategory constructed a vector of 68 dimensions representing the linguistic features of each subject. We used support vector machine and random forest classifiers to distinguish MCI from cognitively intact participants.

RESULTS

MCI participants were distinguished from those with intact cognition using linguistic features obtained by LIWC with 84% classification accuracy which is well above chance 60%.

DISCUSSION

Linguistic analyses of spoken language may be a powerful tool in distinguishing MCI subjects from those with intact cognition. Further studies to assess whether spoken language derived measures could detect changes in cognitive functions in clinical trials are warrented.

Connected Speech in Neurodegenerative Language Disorders: A Review

Language assessment has a crucial role in the clinical diagnosis of several neurodegenerative diseases. The analysis of extended speech production is a precious source of information encompassing the phonetic, phonological, lexico-semantic, morpho-syntactic, and pragmatic levels of language organization. The knowledge about the distinctive linguistic variables identifying language deficits associated to different neurodegenerative diseases has progressively improved in the last years. However, the heterogeneity of such variables and of the way they are measured and classified limits any generalization and makes the comparison among studies difficult. Here we present an exhaustive review of the studies focusing on the linguistic variables derived from the analysis of connected speech samples, with the aim of characterizing the language disorders of the most prevalent neurodegenerative diseases, including primary progressive aphasia, Alzheimer's disease, movement disorders, and amyotrophic lateral sclerosis. A total of 61 studies have been included, considering only those reporting group analysis and comparisons with a group of healthy persons. This review first analyzes the differences in the tasks used to elicit connected speech, namely picture description, story narration, and interview, considering the possible different contributions to the assessment of different linguistic domains. This is followed by an analysis of the terminologies and of the methods of measurements of the variables, indicating the need for harmonization and standardization. The final section reviews the linguistic domains affected by each different neurodegenerative disease, indicating the variables most consistently impaired at each level and suggesting the key variables helping in the differential diagnosis among diseases. While a large amount of valuable information is already available, the review highlights the need of further work, including the development of automated methods, to take advantage of the richness of connected speech analysis for both research and clinical purposes.

Propositional Density in Spoken and Written Language of Czech-Speaking Patients With Mild Cognitive Impairment

PURPOSE

Propositional density (PD) is a measure of content richness in language production that declines in normal aging and more profoundly in dementia. The present study aimed to develop a PD scoring system for Czech and use it to compare PD in language productions of older people with amnestic mild cognitive impairment (aMCI) and control participants matched on age, gender, and education.

METHOD

Groups of patients with aMCI and cognitively healthy control participants (N = 20 each) provided short spoken and written language samples. Two samples were elicited for each modality, 1 describing recent events and 1 describing childhood memories. Series of neuropsychological tests were administered. The groups were compared using t-tests and the relations between measures using correlation coefficients.

RESULTS

PD was lower in spoken productions of patients with aMCI, compared with control participants, but only in language samples using remote memories. PD in these samples was related to verbal fluency and education but not to working memory. PD in written samples did not differ between participants with aMCI and control participants.

CONCLUSIONS

PD in spoken language reflects the cognitive decline in people with aMCI, but the effect is relatively mild. The results support the existing findings that PD is related to verbal fluency.

Alzheimer's Disease: Prototype of Cognitive Deterioration, Valuable Lessons to Understand Human Cognition

It is important for neurologists to become more familiar with neuropsychological evaluation for Alzheimer disease. The growth of this method in research, as an available, inexpensive, and noninvasive diagnostic approach, which can be administered even by non-specialist-trained examiners, makes this knowledge more necessary than ever. Such knowledge has a basic role in planning national programs in primary health care systems for prevention and early detection of Alzheimer disease. This is more crucial in developing countries, which have higher rates of dementia prevalence along with cardiovascular risk factors, lack of public knowledge about dementia, and limited social support. In addition compared to the neurological hard signs which are tangible and measurable, the concept of cognition seems to be more difficult for the neurologists to evaluate and for the students to understand. Dementia in general and Alzheimer's disease as the prototype of cognitive disorders specifically, play an important role to explore all domains of human cognition through its symptomatology and neuropsychological deficits.

Effects of thalamic deep brain stimulation on spontaneous language production

The thalamus is thought to contribute to language-related processing, but specifications of this notion remain vague. An assessment of potential effects of thalamic deep brain stimulation (DBS) on spontaneous language may help to delineate respective functions. For this purpose, we analyzed spontaneous language samples from thirteen (six female / seven male) patients with essential tremor treated with DBS of the thalamic ventral intermediate nucleus (VIM) in their respective ON vs. OFF conditions. Samples were obtained from semi-structured interviews and examined on multidimensional linguistic levels. In the VIM-DBS ON condition, participants used a significantly higher proportion of paratactic as opposed to hypotactic sentence structures. This increase correlated negatively with the change in the more global cognitive score, which in itself did not change significantly. In conclusion, VIM-DBS appears to induce the use of a simplified syntactic structure. The findings are discussed in relation to concepts of thalamic roles in language-related cognitive behavior.

Writing Impairments in Japanese Patients with Mild Cognitive Impairment and with Mild Alzheimer's Disease

Background/Aims

We investigated writing abilities in patients with the amnestic type of mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD). To examine the earliest changes in writing function, we used writing tests for both words and sentences with different types of Japanese characters (Hiragana, Katakana, and Kanji).

Methods

A total of 25 aMCI patients, 38 AD patients, and 22 healthy controls performed writing to dictation for Kana and Kanji words, copied Kanji words, and wrote in response to a picture story task. Analysis of variance was used to test the subject group effects on the scores in the above writing tasks.

Results

For the written Kanji words, the mild AD group performed worse than the aMCI group and the controls, but there was no difference between the aMCI group and the controls. For the picture story writing task, the mild AD and aMCI groups performed worse than the controls, but the difference between the AD and the aMCI groups was not significant.

Conclusions

The mild AD group showed defects in writing Kanji characters, and the aMCI group showed impairments in narrative writing. Our study suggests that narrative writing, which demands complex integration of multiple cognitive functions, can be used to detect the subtle writing deficits in aMCI patients.

Mobility and safety issues in drivers with dementia

Although automobiles remain the mobility method of choice for older adults, late-life cognitive impairment and progressive dementia will eventually impair the ability to meet transport needs of many. There is, however, no commonly utilized method of assessing dementia severity in relation to driving, no consensus on the specific types of assessments that should be applied to older drivers with cognitive impairment, and no gold standard for determining driving fitness or approaching loss of mobility and subsequent counseling. Yet, clinicians are often called upon by patients, their families, health professionals, and driver licensing authorities to assess their patients' fitness-to-drive and to make recommendations about driving privileges. We summarize the literature on dementia and driving, discuss evidenced-based assessments of fitness-to-drive, and outline the important ethical and legal concerns. We address the role of physician assessment, referral to neuropsychology, functional screens, dementia severity tools, driving evaluation clinics, and driver licensing authority referrals that may assist clinicians with an evaluation. Finally, we discuss mobility counseling (e.g. exploration of transportation alternatives) since health professionals need to address this important issue for older adults who lose the ability to drive. The application of a comprehensive, interdisciplinary approach to the older driver with cognitive impairment will have the best opportunity to enhance our patients' social connectedness and quality of life, while meeting their psychological and medical needs and maintaining personal and public safety.

Semantic and syntactic processing of mass and count nouns: data from dementia

In the present research, we investigated the processing of Italian mass and count nouns and of their semantic and morphosyntactic attributes in people with neurodegenerative disease. The performance of a group of 26 Italian participants with Alzheimer's disease was studied in a semantic judgment task and a syntactic judgment task. Results were analyzed by means of mixed-effect models, revealing an interaction between task and stimulus category: The probability for correct responses to mass stimuli was significantly lower than that for count stimuli, but only in the semantic task. These findings confirm the major semantic impairment in dementia and suggest that mass nouns have particular features that make them more prone to impairment than count nouns for a progressively degenerating brain.

Charting the decline in spontaneous writing in Alzheimer's disease: a longitudinal study

OBJECTIVE

This study aims to document the nature and progression of the spontaneous writing impairment observed in patients with Alzheimer's disease (AD) over a 12-month period using both a cross-sectional and prospective longitudinal design.

METHODS

Thirty-one minimal-moderate AD patients and 30 controls matched for age and socio-cultural background completed a simple and complex written description task at baseline. The AD patients then had follow-up assessments at 6 and 12 months.

RESULTS

Cross-sectional comparisons indicated that minimal-moderate AD patients produced more semantic paraphasias, phonological paraphasias, and empty and indefinite phrases, whilst producing fewer pictorial themes, repairing fewer errors, and producing shorter and less complex sentences than controls. The two groups could not be distinguished on visual paraphasias. Longitudinal follow-up, however, suggested that visual processing deteriorates over time, where the prevalence of visual errors increased over 12 months. Discussion The findings suggest that the deterioration of writing skills observed in the spontaneous writings of AD patients shows a pattern of impairment dominated by semantic errors with a secondary impairment in phonological processing, which is later joined by a disruption of visuospatial and graphomotor processing.

A rubric for extracting idea density from oral language samples

While past research has demonstrated that low idea density (ID) scores from natural language samples correlate with late life risk for cognitive decline and Alzheimer's disease pathology, there are no published rubrics for collecting and analyzing language samples for idea density to verify or extend these findings into new settings. This unit outlines the history of ID research and findings, discusses issues with past rubrics, and then presents an operationalized method for the systematic measurement of ID in language samples, with an extensive manual available as a supplement to this unit (Analysis of Idea Density, AID). Finally, reliability statistics for this rubric in the context of dementia research on aging populations and verification that AID can replicate the significant association between ID and late-life cognition are presented.

Spoken Language Derived Measures for Detecting Mild Cognitive Impairment

Spoken responses produced by subjects during neuropsychological exams can provide diagnostic markers beyond exam performance. In particular, characteristics of the spoken language itself can discriminate between subject groups. We present results on the utility of such markers in discriminating between healthy elderly subjects and subjects with mild cognitive impairment (MCI). Given the audio and transcript of a spoken narrative recall task, a range of markers are automatically derived. These markers include speech features such as pause frequency and duration, and many linguistic complexity measures. We examine measures calculated from manually annotated time alignments (of the transcript with the audio) and syntactic parse trees, as well as the same measures calculated from automatic (forced) time alignments and automatic parses. We show statistically significant differences between clinical subject groups for a number of measures. These differences are largely preserved with automation. We then present classification results, and demonstrate a statistically significant improvement in the area under the ROC curve (AUC) when using automatic spoken language derived features in addition to the neuropsychological test scores. Our results indicate that using multiple, complementary measures can aid in automatic detection of MCI.

Aging and the vulnerability of speech to dual task demands

Tracking a digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. Tracking performance by both groups was affected by dual task demands: time on target declined and tracking error increased as dual task demands increased from the baseline condition to a moderately demanding dual task condition to a more demanding dual task condition. When dual task demands were moderate, older adults' speech rate declined but their fluency, grammatical complexity, and content were unaffected. When the dual task was more demanding, older adults' speech, like young adults' speech, became highly fragmented, ungrammatical, and incoherent. Vocabulary, working memory, processing speed, and inhibition affected vulnerability to dual task costs: vocabulary provided some protection for sentence length and grammaticality, working memory conferred some protection for grammatical complexity, and processing speed provided some protection for speech rate, propositional density, coherence, and lexical diversity. Further, vocabulary and working memory capacity provided more protection for older adults than for young adults although the protective effect of processing speed was somewhat reduced for older adults as compared to the young adults.

Language performance in Alzheimer's disease and mild cognitive impairment: a comparative review

Mild cognitive impairment (MCI) manifests as memory impairment in the absence of dementia and progresses to Alzheimer's disease (AD) at a rate of around 15% per annum, versus 1-2% in the general population. It thus constitutes a primary target for investigation of early markers of AD. Language deficits occur early in AD, and performance on verbal tasks is an important diagnostic criterion for both AD and MCI. We review language performance in MCI, compare these findings to those seen in AD, and identify the primary issues in understanding language performance in MCI and selecting tasks with diagnostic and prognostic value.

Language and Dementia: Neuropsychological Aspects

This article reviews recent evidence for the relationship between extralinguistic cognitive and language abilities in dementia. A survey of data from investigations of three dementia syndromes (Alzheimer's disease, semantic dementia and progressive nonfluent aphasia) reveals that, more often than not, deterioration of conceptual organization appears associated with lexical impairments, whereas impairments in executive function are associated with sentence- and discourse-level deficits. These connections between extralinguistic functions and language ability also emerge from the literature on cognitive reserve and bilingualism that investigates factors that delay the onset and possibly the progression of neuropsychological manifestation of dementia.

Verb acquisition and representation in Alzheimer's disease

We examined the implicit acquisition and mental representation of a novel verb in patients with probable Alzheimer's disease (AD). Patients were exposed to the new verb in a naturalistic manner as part of a simple picture story. We probed grammatical, semantic and thematic matrix knowledge of the verb soon after presentation and again 1 week later. We found partial verb acquisition that was retained over 1 week. AD patients did not differ from controls in their acquisition and retention of a new verb's major grammatical subcategory, although they acquired little of its semantic properties and displayed minimal acquisition of the new word's thematic matrix. Moreover, AD patients appeared to maintain their acquired grammatical knowledge over 1 week. We discuss the implications of these findings from several perspectives, including the modularity of the language processing system, the relationship between episodic memory and semantic memory, and the role of the preserved implicit memory system in AD patients' partially successful lexical acquisition.

Dysgraphia in Alzheimer's disease: a review for clinical and research purposes

PURPOSE

This article presents a critical review of literature on dysgraphia associated with Alzheimer's disease (AD). Research presented includes discussions of central and peripheral spelling impairments as well as the impact of general, nonlinguistic cognitive functions on dysgraphia associated with AD.

METHOD

The studies critically reviewed were from a variety of disciplines, with emphasis on seminal work, recent literature, and the first author's research.

CONCLUSIONS

Studies have shown that writing impairment is heterogeneous within the AD population; however, there are certain aspects of the writing process that are more vulnerable than others and may serve as diagnostic signs. Identifying patterns of writing impairment at different stages of AD may help to chart disease progression and assist in the development of appropriate interventions.

Handwriting Process Variables Discriminating Mild Alzheimer's Disease and Mild Cognitive Impairment

This study's aims were (a) to examine kinematically the handwriting process of persons with mild cognitive impairment (MCI), compared with those with mild Alzheimer's disease and healthy controls; (b) to assess the importance of these measures for the differentiation of the groups; and (c) to assess characteristics of the handwriting process across different functional tasks. Thirty-one persons with MCI, 22 with mild Alzheimer's disease, and 41 healthy controls performed functional tasks while using a computerized system. We found significant differences between the groups in almost all measures, with the MCI group assuming a position between the other groups. Temporal measures were higher and pressure was lower in more cognitively deteriorated groups. Information gathered about kinematic measures, together with cognitive functioning, allowed us to classify 69% to 72% of the participants correctly, although the classification for the MCI group was relatively poor.

A comparison of verbal and written language in Alzheimer's disease

Few studies have examined characteristics of both verbal and written language of individuals with Alzheimer's disease (AD). This study used parallel measures (picture description, word fluency, spelling to dictation, and confrontational naming) to compare verbal and written language of individuals with mild AD, moderate AD, and normal controls (14 participants per group). Goals were to determine whether verbal/written differences would be exhibited within groups, and to identify measures sensitive to the effects of mild AD. Results showed that increasing AD severity led to decline in performance for most tasks, but only word fluency differentiated subjects with mild AD from normal controls. Confrontational naming was the only task to identify a difference in verbal and written performance for an AD group but not controls; moderate AD subjects performed worse in written naming. Similar verbal and written performance for the spelling to dictation task indicates impairment to central spelling processes in AD.

LEARNING OUTCOMES

As a result of this activity, participants will be able to: (1) identify verbal and written language measures which are sensitive to the effects of mild AD; (2) describe similarities and differences in verbal and written language performance among mild AD subjects, moderate AD subjects, and controls; (3) describe how findings may inform clinical practice for individuals with mild AD.

Verb deficits in Alzheimer's disease and agrammatism: implications for lexical organization

This study examined the nature of verb deficits in 14 individuals with probable Alzheimer's Disease (PrAD) and nine with agrammatic aphasia. Production was tested, controlling both semantic and syntactic features of verbs, using noun and verb naming, sentence completion, and narrative tasks. Noun and verb comprehension and a grammaticality judgment task also were administered. Results showed that while both PrAD and agrammatic subjects showed impaired verb naming, the syntactic features of verbs (i.e., argument structure) influenced agrammatic, but not Alzheimer's disease patients' verb production ability. That is, agrammatic patients showed progressively greater difficulty with verbs associated with more arguments, as has been shown in previous studies (e.g., Kim & Thompson, 2000; Thompson, 2003; Thompson, Lange, Schneider, & Shapiro, 1997), and suggest a syntactic basis for verb production deficits in agrammatism. Conversely, the semantic complexity of verbs affected PrAD, but not agrammatic, patients' performance, suggesting "bottom-up" breakdown in their verb lexicon, paralleling that of nouns, resulting from the degradation or loss of semantic features of verbs.

Oral and written language in late adulthood: findings from the Nun Study

As a part of the Nun Study, a longitudinal investigation of aging and Alzheimer's disease, oral and written autobiographies from 118 older women were analyzed to examine the relationship between spoken and written language. The written language samples were more complex than the oral samples, both conceptually and grammatically. The relationship between the linguistic measures and participant characteristics was also examined. The results suggest that the grammatical and conceptual characteristics of oral and written language are affected by participant differences in education, cognitive status, and physical function and that written language samples have greater power than oral language samples to differentiate between high- and low-ability older adults.