Anomia as a marker of distinct semantic memory impairments in Alzheimer's disease and semantic dementia

Semantic Priming from Uncued Distractors in Alzheimer's Disease

RESEARCH QUESTION

Are semantic impairments in Alzheimer's disease (AD) partially due to deficits in spatial attention?

METHODS AND RESULTS

In a target detection task, both older adults (OAs) and AD individuals were facilitated by valid spatial cues, but only OAs were impaired by invalid cues compared to neutral. In a reading task, spatial cues validly or invalidly cued the location of pictures, which were related or unrelated to subsequent, centrally presented, words. OAs showed semantic priming only after valid cues, whereas AD individuals showed priming after valid and invalid cues.

DISCUSSION

Failure to inhibit uncued locations results in processing of potentially distracting semantic information in AD.

Cognitive decline assessment using semantic linguistic content and transformer deep learning architecture

BACKGROUND

Dementia is a cognitive decline that leads to the progressive deterioration of an individual's ability to perform daily activities independently. As a result, a considerable amount of time and resources are spent on caretaking. Early detection of dementia can significantly reduce the effort and resources needed for caretaking.

AIMS

This research proposes an approach for assessing cognitive decline by analysing speech data, specifically focusing on speech relevance as a crucial indicator for memory recall.

METHODS & PROCEDURES

This is a cross-sectional, online, self-administered. The proposed method used deep learning architecture based on transformers, with BERT (Bidirectional Encoder Representations from Transformers) and Sentence-Transformer to derive encoded representations of speech transcripts. These representations provide contextually descriptive information that is used to analyse the relevance of sentences in their respective contexts. The encoded information is then compared using cosine similarity metrics to measure the relevance of uttered sequences of sentences. The study uses the Pitt Corpus Dementia dataset for experimentation, which consists of speech data from individuals with and without dementia. The accuracy of the proposed multi-QA-MPNet (Multi-Query Maximum Inner Product Search Pretraining) model is compared with other pretrained transformer models of Sentence-Transformer.

OUTCOMES & RESULTS

The results show that the proposed approach outperforms the other models in capturing context level information, particularly semantic memory. Additionally, the study explores the suitability of different similarity measures to evaluate the relevance of uttered sequences of sentences. The experimentation reveals that cosine similarity is the most appropriate measure for this task.

CONCLUSIONS & IMPLICATIONS

This finding has significant implications for the early warning signs of dementia, as it suggests that cosine similarity metrics can effectively capture the semantic relevance of spoken language. The persistent cognitive decline over time acts as one of the indicators for prevalence of dementia. Additionally early dementia could be recognised by analysis on other modalities like speech and brain images.

WHAT THIS PAPER ADDS

What is already known on this subject It is already known that speech- and language-based detection methods can be useful for dementia diagnosis, as language difficulties are often early signs of the disease. Additionally, deep learning algorithms have shown promise in detecting and diagnosing dementia through analysing large datasets, particularly in speech- and language-based detection methods. However, further research is needed to validate the performance of these algorithms on larger and more diverse datasets and to address potential biases and limitations. What this paper adds to existing knowledge This study presents a unique and effective approach for cognitive decline assessment through analysing speech data. The study provides valuable insights into the importance of context and semantic memory in accurately detecting the potential in dementia and demonstrates the applicability of deep learning models for this purpose. The findings of this study have important clinical implications and can inform future research and development in the field of dementia detection and care. What are the potential or actual clinical implications of this work? The proposed approach for cognitive decline assessment using speech data and deep learning models has significant clinical implications. It has the potential to improve the accuracy and efficiency of dementia diagnosis, leading to earlier detection and more effective treatments, which can improve patient outcomes and quality of life.

Smartphone use as an efficient tool to improve anomia in primary progressive aphasia

Cognitive interventions are helpful in the non-pharmacological management of Primary progressive aphasia (PPA) and other neurodegenerative disorders of cognition, by helping patients to compensate for their cognitive deficits and improve their functional independence. In this study, we examined the effectiveness of cognitive rehabilitation based on the use of mobile device technology in PPA. The aim of this research study was to determine if BL, a patient with semantic variant PPA (svPPA) and severe anomia, was able to learn using specific smartphone functions and an application to reduce her word finding difficulties. She was trained during the intervention sessions on a list of target pictures to measure changes in picture naming performance. Errorless learning was applied during learning. BL quickly learned to use smartphone functions and the application over the course of the intervention. She significantly improved her anomia for trained pictures, and to a lesser extent for untrained semantically related pictures. Picture naming performance was maintained six months after the intervention, and she continued to use her smartphone regularly to communicate with family members and friends. This study confirms that smartphone use can be learned in PPA, which can help reduce the symptoms of anomia and improve communication skills.

Factor structure and clinical applicability of new semantic tasks in Alzheimer's disease and aphasia

Semantic tasks are frequently used when examining language functions in patients with acquired disorders such as Alzheimer's disease (AD) and aphasia. Little is known about the possible covariation between different types of tasks or their factor structure in healthy adults. Additionally, few studies have examined semantic task performances in different patient groups. The aims of this data-driven study were to examine the factor structure in a wide range of semantic tasks in healthy older adults, the possible differences in factor variables between healthy controls, patients with AD and patients with stroke aphasia, as well as the clinical applicability of tasks in differentiating the two patient groups from controls. Participants included 59 healthy older adults, 13 patients with AD and 14 patients with aphasia. The results indicated a four-factor solution for the semantic task variables: (1) the Semantic association factor, (2) the Time factor, (3) the Verbal factor and (4) the Synonym factor. The Verbal factor was the only distinguishing factor between the two patient groups. Three factors reliably discriminated between the controls and the AD patients, and the Verbal factor reliably discriminated between the controls and the aphasia patients. In addition, a few single task variables showed outstanding discrimination for both patient groups. This study supports the notions of semantic tasks tapping into more than one cognitive subcomponent and a more general semantic impairment in AD than in aphasia. In clinical assessment, choosing appropriate semantic tasks is crucial in order to reliably detect the characteristics of the impairment.

Guess What We Can Hear-Novel Voice Biomarkers for the Remote Detection of Disease

The advancement of digital biomarkers and the provision of remote health care greatly progressed during the coronavirus disease 2019 global pandemic. Combining voice/speech data with artificial intelligence and machine-based learning offers a novel solution to the growing demand for telemedicine. Voice biomarkers, obtained from the extraction of characteristic acoustic and linguistic features, are associated with a variety of diseases and even coronavirus disease 2019. In the current review, we (1) describe the basis on which digital voice biomarkers could facilitate "telemedicine," (2) discuss potential mechanisms that may explain the association between voice biomarkers and disease, (3) offer a novel classification system to conceptualize voice biomarkers depending on different methods for recording and analyzing voice/speech samples, (4) outline evidence revealing an association between voice biomarkers and a number of disease states, and (5) describe the process of developing a voice biomarker from recording, storing voice samples, and extracting acoustic and linguistic features relevant to training and testing deep and machine-based learning algorithms to detect disease. We further explore several important future considerations in this area of research, including the necessity for clinical trials and the importance of safeguarding data and individual privacy. To this end, we searched PubMed and Google Scholar to identify studies evaluating the relationship between voice/speech features and biomarkers and various diseases. Search terms included digital biomarker, telemedicine, voice features, voice biomarker, speech features, speech biomarkers, acoustics, linguistics, cardiovascular disease, neurologic disease, psychiatric disease, and infectious disease. The search was limited to studies published in English in peer-reviewed journals between 1980 and the present. To identify potential studies not captured by our database search strategy, we also searched studies listed in the bibliography of relevant publications and reviews.

The Dynamic Interplay between Loss of Semantic Memory and Semantic Learning Capacity: Insight from Neologisms Learning in Semantic Variant Primary Progressive Aphasia

Semantic Variant of Primary Progressive Aphasia (svPPA) has often been considered as a loss of knowledge stored in semantic memory, but might also be due to a general disruption of mechanisms allowing the acquisition, storage, and retrieval of semantic memories. In order to assess any parallelism in svPPA patients between loss of semantic knowledge and inability to acquire new semantic information, we administered a battery of semantic learning tasks to healthy individuals and svPPA patients, where they were requested to learn new conceptual representations and new word forms, and to associate the former with the latter. A strong relation was found between loss of semantic knowledge and disruption of semantic learning: (a) patients with severe svPPA had the lowest scores in the semantic learning tasks; (b) significant correlations were found between scores obtained in semantic learning tasks and scores obtained in semantic memory disorders in svPPA patients.

Distinguishing Semantic Variant Primary Progressive Aphasia from Alzheimer’s Disease

The differentiation of semantic variant primary progressive aphasia from dementia and Alzheimer’s disease can be difficult, particularly when the semantic anomia is pronounced. This report describes a patient who presented with complaints of memory loss and proved to have prominent semantic loss of all types of nouns, common and proper, concrete and abstract, yet continued to live independently and maintain his activities of daily living. The evaluation was consistent for semantic variant primary progressive aphasia with degradation of semantic knowledge and focal anterior temporal atrophy and hypometabolism. This report summarizes the literature and discusses the differential diagnosis of this disorder from Alzheimer’s disease and related dementias.

Baseline Conceptual-Semantic Impairment Predicts Longitudinal Treatment Effects for Anomia in Primary Progressive Aphasia and Alzheimer's Disease

Background

An individual's diagnostic subtype may fail to predict the efficacy of a given type of treatment for anomia. Classification by conceptual-semantic impairment may be more informative.

Aims

This study examined the effects of conceptual-semantic impairment and diagnostic subtype on anomia treatment effects in primary progressive aphasia (PPA) and Alzheimer's disease (AD).

Methods & Procedures

At baseline, the picture and word versions of the Pyramids and Palm Trees and Kissing and Dancing tests were used to measure conceptual-semantic processing. Based on norming that was conducted with unimpaired older adults, participants were classified as being impaired on both the picture and word versions (i.e., modality-general conceptual-semantic impairment), the picture version (Objects or Actions) only (i.e., visual-conceptual impairment), the word version (Nouns or Verbs) only (i.e., lexical-semantic impairment), or neither the picture nor the word version (i.e., no impairment). Following baseline testing, a lexical treatment and a semantic treatment were administered to all participants. The treatment stimuli consisted of nouns and verbs that were consistently named correctly at baseline (Prophylaxis items) and/or nouns and verbs that were consistently named incorrectly at baseline (Remediation items). Naming accuracy was measured at baseline, and it was measured at three, seven, eleven, fourteen, eighteen, and twenty-one months.

Outcomes & Results

Compared to baseline naming performance, lexical and semantic treatments both improved naming accuracy for treated Remediation nouns and verbs. For Prophylaxis items, lexical treatment was effective for both nouns and verbs, and semantic treatment was effective for verbs, but the pattern of results was different for nouns -- the effect of semantic treatment was initially nonsignificant or marginally significant, but it was significant beginning at 11 Months, suggesting that the effects of prophylactic semantic treatment may become more apparent as the disorder progresses. Furthermore, the interaction between baseline Conceptual-Semantic Impairment and the Treatment Condition (Lexical vs. Semantic) was significant for verb Prophylaxis items at 3 and 18 Months, and it was significant for noun Prophylaxis items at 14 and 18 Months.

Conclusions

The pattern of results suggested that individuals who have modality-general conceptual-semantic impairment at baseline are more likely to benefit from lexical treatment, while individuals who have unimpaired conceptual-semantic processing at baseline are more likely to benefit from semantic treatment as the disorder progresses. In contrast to conceptual-semantic impairment, diagnostic subtype did not typically predict the treatment effects.

SymCog: An open-source toolkit for assessing human symbolic cognition

Symbol systems have a profound influence on human behavior, spanning countless modalities such as natural language, clothing styles, monetary systems, and gestural conventions (e.g., handshaking). Selective impairments in understanding and manipulating symbols are collectively known as asymbolia. Here we address open questions about the nature of asymbolia in the context of both historical and contemporary approaches to human symbolic cognition. We describe a tripartite perspective on symbolic cognition premised upon (1) mental representation of a concept, (2) a stored pool of symbols segregated from their respective referents, and (3) fast and accurate mapping between concepts and symbols. We present an open-source toolkit for assessing symbolic knowledge premised upon matching animated video depictions of abstract concepts to their corresponding verbal and nonverbal symbols. Animations include simple geometric shapes (e.g., filled circles, squares) moving in semantically meaningful ways. For example, a rectangle bending under the implied weight of a large square denotes "heaviness." We report normative data for matching words and images to these target animations. In a second norming study, participants rated target animations across a range of semantic dimensions (e.g., valence, dominance). In a third study, we normed a set of concepts familiar to American English speakers but lacking verbal labels (e.g., the feeling of a Sunday evening). We describe how these tools may be used to assess human symbolic processing and identify asymbolic deficits across the span of human development.

Validation of and Normative Data of the DVAQ-30, a New Video-Naming Test for Assessing Verb Anomia

OBJECTIVE

Anomia is usually assessed using picture-naming tests. While many tests evaluate anomia for nouns, very few tests have been specifically designed for verb anomia. This article presents the DVAQ-30, a new naming test for detecting verb anomia in adults and elderly people.

METHOD

The article describes three studies. Study 1 focused on the DVAQ-30 development phase. In Study 2, healthy participants and individuals with post-stroke aphasia, mild cognitive impairment, Alzheimer's disease, or primary progressive aphasia were assessed using the DVAQ-30 to establish its convergent and discriminant validity, test-retest reliability, and internal consistency. In Study 3, a group of adults and elderly Quebec French-speaking adults were assessed to obtain normative data.

RESULTS

The DVAQ-30 had good convergent validity and distinguished the performance of healthy participants from that of participants with pathological conditions. The test also had good internal consistency, and the test-retest analysis showed that the scores had good temporal stability. Furthermore, normative data were collected on the performance of 244 participants aged 50 years old and over.

CONCLUSIONS

The DVAQ-30 fills an important gap and has the potential to help clinicians and researchers better detect verb anomia associated with pathological aging and post-stroke aphasia.

Learning From Mistakes: Cognitive and Metabolic Correlates of Errors on Picture Naming in the Alzheimer’s Disease Spectrum

Background: Analysis of subtypes of picture naming errors produced by patients with Alzheimer’s disease (AD) have seldom been investigated yet may clarify the cognitive and neural underpinnings of naming in the AD spectrum. Objective: To elucidate the neurocognitive bases of picture naming in AD through a qualitative analysis of errors. Methods: Over 1000 naming errors produced by 70 patients with amnestic, visuospatial, linguistic, or frontal AD were correlated with general cognitive tests and with distribution of hypometabolism on FDG-PET. Results: Principal component analysis identified 1) a Visual processing factor clustering visuospatial tests and unrecognized stimuli, pure visual errors and visual-semantic errors, associated with right parieto-occipital hypometabolism; 2) a Concept-Lemma factor grouping language tests and anomias, circumlocutions, superordinates, and coordinates, correlated with left basal temporal hypometabolism; 3) a Lemma-Phonology factor including the digit span and phonological errors, linked with left temporo-parietal hypometabolism. Regression of brain metabolism on individual errors showed that errors due to impairment of basic and higher-order processing of object visual attributes or of their interaction with semantics, were related with bilateral occipital and left occipito-temporal dysfunction. Omissions and superordinates were linked to degradation of broad and basic concepts in the left basal temporal cortex. Semantic-lexical errors derived from faulty semantically- and phonologically-driven lexical retrieval in the left superior and middle temporal gyri. Generation of nonwords was underpinned by of phonological impairment within the left inferior parietal cortex. Conclusion: Analysis of individual naming errors allowed to outline a comprehensive anatomo-functional model of picture naming in classical and atypical AD.

Knowledge Representations Derived From Semantic Fluency Data

The semantic fluency task is commonly used as a measure of one’s ability to retrieve semantic concepts. While performance is typically scored by counting the total number of responses, the ordering of responses can be used to estimate how individuals or groups organize semantic concepts within a category. I provide an overview of this methodology, using Alzheimer’s disease as a case study for how the approach can help advance theoretical questions about the nature of semantic representation. However, many open questions surrounding the validity and reliability of this approach remain unresolved.

Dysfunctional Tissue Correlates of Unrelated Naming Errors in Acute Left Hemisphere Stroke

Most naming error lesion-symptom mapping (LSM) studies have focused on semantic and/or phonological errors. Anomic individuals also produce unrelated word errors, which may be linked to semantic or modality-independent lexical deficits. To investigate the neural underpinnings of rarely-studied unrelated errors, we conducted LSM analyses in 100 individuals hospitalized with a left hemisphere stroke who completed imaging protocols and language assessments. We used least absolute shrinkage and selection operator regression to capture relationships between naming errors and dysfunctional brain tissue metrics (regional damage or hypoperfusion in vascular territories) in two groups: participants with and without impaired single-word auditory comprehension. Hypoperfusion-particularly within the parietal lobe-was an important error predictor, especially for the unimpaired group. In both groups, higher unrelated error proportions were associated with primarily ventral stream damage, the language route critical for processing meaning. Nonetheless, brain metrics implicated in unrelated errors were distinct from semantic error correlates.

Language training for oral and written naming impairment in primary progressive aphasia: a review

BACKGROUND

Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by a gradual, insidious and progressive loss of language abilities, with naming difficulties being an early and persistent impairment common to all three variants. In the absence of effective pharmacological treatments and given the progressive nature of the disorder, in the past few decades, many studies have investigated the effectiveness of language training to minimize the functional impact of word-finding difficulties in daily life.

MAIN BODY

We review language treatments most commonly used in clinical practice among patients with different variants of PPA, with a focus on the enhancement of spoken and written naming abilities. Generalization of gains to the ability to name untrained stimuli or to other language abilities and the maintenance of these results over time are also discussed. Forty-eight studies were included in this literature review, identifying four main types of language treatment: a) lexical retrieval treatment, b) phonological and/or orthographic treatment, c) semantic treatment, and d) a multimodality approach treatment. Overall, language training is able to induce immediate improvements of naming abilities in all variants of PPA. Moreover, despite the large variability among results, generalization and long-term effects can be recorded after the training. The reviewed studies also suggest that one factor that determines the choice of a particular approach is the compromised components of the lexical/semantic processing system.

CONCLUSION

The majority of studies have demonstrated improvements of naming abilities following language treatments. Given the progressive nature of PPA, it is essential to apply language treatment in the early stages of the disease.

fMRI Investigation of Semantic Lexical Processing in Healthy Control and Alzheimer's Disease Subjects Using Naming Task: A Preliminary Study

For decades, scientists have been trying to solve the problem of dementia, with no cure currently available. Semantic-lexical impairment is well established as the early critical sign of dementia, although there are still gaps in knowledge that must be investigated. In this study, we used fMRI to observe the neural activity of 31 subjects, including 16 HC (Healthy Control) and 15 AD (Alzheimer's Disease), who participated in the naming task. The neuropsychology profile of HC (Healthy Control) and AD (Alzheimer's Disease) are discussed in this study. The involvement of FG (Fusiform Gyrus) and IFG (Inferior Frontal Gyrus) shows dominant activation in both of the groups. We observed a decrease in neural activity in the AD group, resulting in semantic deficit problems in this preliminary study. Furthermore, ROI analysis was performed and revealed both hyperactivation and hypoactivation in the AD group. The compensatory mechanism demonstrated during the task, due to the effort required to identify an animal's name, represents the character profile of AD.

Uniform data set language measures for bvFTD and PPA diagnosis and monitoring

INTRODUCTION

The Frontotemporal Lobar Degeneration Module (FTLD-MOD) includes a neuropsychological battery designed to assess the clinical features of FTLD, although much is unknown about its utility. We investigated FTLD-MOD and Uniform Data Set 3.0 (UDS) language tests for differential diagnosis and disease monitoring.

METHODS

Linear regressions compared baseline performances in 1655 National Alzheimer's Coordinating Center participants (behavioral variant frontotemporal dementia (bvFTD, n = 612), semantic variant primary progressive aphasia (svPPA, n = 168), non-fluent/agrammatic variant PPA (nfvPPA, n = 168), logopenic variant PPA (lvPPA, n = 109), and controls (n = 581)). Sample sizes to detect treatment effects were estimated using longitudinal data.

RESULTS

Among PPAs, the FTLD-MOD language tasks and UDS Multilingual Naming Test accurately discriminated svPPA. Number Span Forward best discriminated lvPPA; Phonemic:Semantic Fluency ratio was excellent for nfvPPA classification. UDS fluency and naming measures required the smallest sample size to detect meaningful change.

DISCUSSION

The FTLD-MOD and UDS differentiated among PPA subtypes. UDS 3.0 measures performed best for longitudinal monitoring.

Salivary cortisol is associated with cognitive changes in patients with fibromyalgia

Fibromyalgia (FM) is a stress-related chronic pain disorder with common cognitive complaints. This study characterized cognitive dysfunction in patients with FM and explored whether these changes are linked to altered cortisol levels. Consecutive 44 patients with FM and 48 healthy controls were enrolled for the assessments of subjective and objective cognitive functions and diurnal levels of salivary cortisol (sampled at awakening, 30 min after awakening, 3 pm, and bedtime). All measurements were compared between the groups and evaluated for clinical correlation. The FM group had more subjective cognitive complaints and performed poorer in objective cognitive testing in memory (delayed recall in Chinese Version Verbal Learning Test and Taylor Complex Figure Test), language (Boston Naming Test), and executive domains (Wisconsin Card Sorting Test) after adjustments for education. The diurnal cortisol levels of patients with FM tended to be lower, especially at 30 min after awakening and bedtime. Moreover, moderate positive correlations existed between the Chinese Version Verbal Learning Test, Boston Naming Test and the morning cortisol levels within the FM group. We suggested the altered cognitive function in FM may be linked to stress maladaptation. Future studies are warranted to elucidate whether stress management improves cognitive performance in patients with FM.

Voice for Health: The Use of Vocal Biomarkers from Research to Clinical Practice

Diseases can affect organs such as the heart, lungs, brain, muscles, or vocal folds, which can then alter an individual's voice. Therefore, voice analysis using artificial intelligence opens new opportunities for healthcare. From using vocal biomarkers for diagnosis, risk prediction, and remote monitoring of various clinical outcomes and symptoms, we offer in this review an overview of the various applications of voice for health-related purposes. We discuss the potential of this rapidly evolving environment from a research, patient, and clinical perspective. We also discuss the key challenges to overcome in the near future for a substantial and efficient use of voice in healthcare.

Identification of digital voice biomarkers for cognitive health

AIM

Human voice contains rich information. Few longitudinal studies have been conducted to investigate the potential of voice to monitor cognitive health. The objective of this study is to identify voice biomarkers that are predictive of future dementia.

METHODS

Participants were recruited from the Framingham Heart Study. The vocal responses to neuropsychological tests were recorded, which were then diarized to identify participant voice segments. Acoustic features were extracted with the OpenSMILE toolkit (v2.1). The association of each acoustic feature with incident dementia was assessed by Cox proportional hazards models.

RESULTS

Our study included 6, 528 voice recordings from 4, 849 participants (mean age 63 ± 15 years old, 54.6% women). The majority of participants (71.2%) had one voice recording, 23.9% had two voice recordings, and the remaining participants (4.9%) had three or more voice recordings. Although all asymptomatic at the time of examination, participants who developed dementia tended to have shorter segments than those who were dementia free (P < 0.001). Additionally, 14 acoustic features were significantly associated with dementia after adjusting for multiple testing (P < 0.05/48 = 1 × 10-3). The most significant acoustic feature was jitterDDP_sma_de (P = 7.9 × 10-7), which represents the differential frame-to-frame Jitter. A voice based linear classifier was also built that was capable of predicting incident dementia with area under curve of 0.812.

CONCLUSIONS

Multiple acoustic and linguistic features are identified that are associated with incident dementia among asymptomatic participants, which could be used to build better prediction models for passive cognitive health monitoring.

Evaluating a Maintenance-Based Treatment Approach to Preventing Lexical Dropout in Progressive Anomia

Purpose Primary progressive aphasia (PPA) and the amnestic variant of Alzheimer's disease (AD) are neurodegenerative conditions characterized by a profound loss of functional communication abilities. Communicative impairment in AD and PPA is especially apparent in the domain of naming common objects and familiar faces. We evaluated the effectiveness of a language intervention targeting maintenance of an individualized core vocabulary in a longitudinal cohort of older adults experiencing either PPA or AD. Method PPA (n = 9) and AD (n = 1) patients were administered a semantically based language treatment for up to 2 years. Patients repeatedly named and generated semantic features for a personalized lexicon consisting of 100 words. We evaluated naming accuracy and off-line neuropsychological measures at four successive timepoints. Naming accuracy was assessed in patients (n = 7) who completed at least three recurrent evaluations. Off-line neuropsychological performance was assessed across timepoints in all patients. Results Patients demonstrated relative preservation of naming trained words relative to a steep decline for untrained (control) words. The greatest decrements were observed for naming people relative to objects. Conclusion These results suggest that consistent training of a finite set of words can protect a core lexicon composed of crucial target concepts (e.g., a spouse's name). We discuss potential benefits and clinical implications of maintenance-based approaches to promoting language functioning in the context of neurodegeneration.

Intensive naming training for low-educated demented and non-demented elderly

ABSTRACT. Complaints about naming difficulties may be common in the elderly. In dementia, anomia is the most frequent symptom of language disorders. Naming training can improve lexical access and promote better quality of communication for elderly with or without dementia. Objective: To analyze naming scores, response time and the generalization of responses for naming of neurotypical and demented low-educated older adults before and after receiving a naming training program, with and without oral comprehension stimulation. Method: Twenty elderly participants, 10 with dementia and 10 neurotypical, were included after interview, screening for cognition and functionality. The naming training was based on retrieval practice and carried out in 5 sessions. Half of the group underwent exclusive naming training, while the other half received naming training associated with oral comprehension stimulation. Results: Elderly people with dementia performed better after training for scores on oral naming and comprehension of oral words, except for object manipulation. The response time for naming trained and untrained stimuli was also better for elderly people with dementia. After the intervention, neurotypical individuals performed statistically better in comprehension time and in the score in oral naming, comprehension of oral words and object manipulation, for trained and untrained words. Conclusion: Naming training, exclusive or associated with oral comprehension, using the recovery technique benefits the language performance of neurotypical and demented elderly, and provides improvements even for untrained stimuli.

Eyetracking during picture naming predicts future vocabulary dropout in progressive anomia

The dynamic and unpredictable nature of expressive vocabulary dropout in progressive anomia presents a challenge for language intervention. We evaluated whether eye gaze patterns during naming could predict anomia for the same items in the near future. We tracked naming accuracy and gaze patterns as patients with semantic (n = 7) or logopenic (n = 2) variants of Primary Progressive Aphasia or amnestic Alzheimer's Disease (n = 1), named photographs of people and objects. Patients were tested three or more times spaced roughly evenly over an average duration of 19.1 months. Target words named accurately at baseline were retrospectively coded as either known (i.e., consistently named) or vulnerable (i.e., inaccurately or inconsistently named) based on naming accuracy over the study interval. We extracted gaze data corresponding to successful naming attempts and implemented logistic mixed effects models to determine whether common gaze measures could predict each word's naming status as known or vulnerable. More visual fixations and greater visual fixation dispersion predicted later anomia. These findings suggest that eye tracking may yield a biomarker of the robustness of particular target words to future expressive vocabulary dropout. We discuss the potential utility of this finding for optimizing treatment for progressive anomia.

Clinical Features of Late-onset Semantic Dementia

BACKGROUND

Semantic dementia (SD) is characterized by progressive semantic anomia extending to a multimodal loss of semantic knowledge. Although often considered an early-onset dementia, SD also occurs in later life, when it may be misdiagnosed as Alzheimer disease (AD).

OBJECTIVE

To evaluate late-onset SD in comparison to early-onset SD and to AD.

METHODS

We identified 74 individuals with SD and then compared those with late-onset SD (≥65 years of age) to those with early-onset SD (<65) on demographic and clinical features. We also compared a subgroup of 23 of the late-onset SD individuals with an equal number of individuals with clinically probable AD.

RESULTS

Twenty-six (35.1%) of the SD individuals were late onset, and 48 (64.9%) were early onset. There were no differences between the two groups on clinical measures, although greater asymmetry of temporal involvement trended to significance in the late-onset SD group. Compared to the 23 AD individuals, the subgroup of 23 late-onset SD individuals had worse performance on confrontational naming, irregular word reading, and face recognition; however, this subgroup displayed better verbal delayed recall and constructions. The late-onset SD individuals also experienced early personality changes at a time when most individuals with AD had not yet developed behavioral changes.

CONCLUSIONS

Approximately one-third of SD individuals may be late onset, and the differentiation of late-onset SD from AD can lead to better disease management, education, and prognosis. SD may be distinguished by screening for disproportionate changes in reading, face recognition, and personality.

Multimodal semantic battery to monitor progressive loss of concepts in the semantic variant of primary progressive aphasia (svPPA): an innovative proposal

Semantic variant primary progressive aphasia (svPPA) is a rare neurodegenerative disease characterized by a progressive loss of semantic knowledge. Patients with svPPA show anomia, impaired word comprehension, poor object recognition, and difficulties in retrieving semantic information. svPPA is also a unique "natural" model that allows clinicians and cognitive neuroscientists to study the organization of semantic memory because only semantic knowledge is affected in the initial period of the disease, with relative sparing of other cognitive domains. In the clinical practice, semantic memory is commonly tested only with verbal tests. The aim of the present study was to preliminary test a new Multimodal Semantic Battery developed in our laboratory, which comprised 11 subtests designed to assess the semantic knowledge of multiple items via all input modalities. The battery was administered twice, over four years, to a patient diagnosed with svPPA. We found that when extensively tested with multiple tests, in some cases, he was still able to recall semantic features of the items that otherwise would not have emerged with standard semantic tests. These results are discussed for the clinical practice: monitoring semantic memory through all modalities in a practical and reliable way could be useful for both clinicians and experimental researchers to better investigate the breakdown of semantic knowledge.

Neural Correlates of Verb Fluency Performance in Cognitively Healthy Older Adults and Individuals With Dementia: A Pilot fMRI Study

Currently there are ~6 million Americans who are affected by dementia. Verbal fluency tasks have been commonly and frequently utilized to document the disease progression in many forms of dementia. Verb fluency has been found to display substantial potential to detect and monitor the cognitive declines of individuals with dementia who have fronto-striatal involvement. The neural substrates underlying verb fluency task performance, however, have remained unclear so far, especially in individuals with dementia. Therefore, in the current study, brain activation patterns of seven individuals with dementia and nine healthy older adults were investigated using functional MRI. The participants performed in the scanner an overt, subject-paced verb fluency task, representative of fluency tasks used in clinical settings. The brain activation patterns during the verb fluency task were compared between the two groups, and a correlational analysis was conducted to determine the neural correlates of verb fluency performance. The results suggest that compared to healthy older adults, individuals with dementia demonstrated poorer verb fluency performance and showed higher activation in specific neural regions, such as the bilateral frontal lobe. In addition, the correlational analysis revealed that poorer verb fluency performance lead to increased activation in certain cortical and subcortical areas, including left hippocampus and right supramarginal gyrus. The current findings are consistent with previous neurophysiological findings related to semantic (noun) fluency performance in older adults and individuals with dementia and add to the empirical evidence that supports the role of the frontal lobe and hippocampus in verb retrieval and search. Declines in verb fluency performance cannot only be used as a cognitive marker, but also represent neuropathological changes due to the neurodegenerative disease.

Naming and Knowing Revisited: Eyetracking Correlates of Anomia in Progressive Aphasia

Progressive naming impairment (i.e., anomia) is a core diagnostic symptom of numerous pathologies that impact anterior and inferior portions of the temporal lobe. For patients who experience such regional temporal lobe degeneration, patterns of language loss often parallel the degradation of semantic memory, an etiology of naming impairment known as semantic anomia. Previous studies of semantic anomia have focused extensively on the output of naming attempts by contrasting errors, omissions, and distortions as a function of item-level characteristics (e.g., prototypicality, semantic category). An alternative approach involves evaluating visual confrontation naming as the naming process unfolds. Techniques with high temporal resolution (e.g., eyetracking) offer a potentially sensitive mode of delineating the locus of impairment during naming. For example, a lexical retrieval disorder would hypothetically elicit normal gaze patterns associated with successful visual object recognition regardless of naming accuracy. In contrast, we hypothesize that semantic anomia would be distinguished by aberrant gaze patterns as a function of reduced top-down conceptually guided search. Here we examined visual object recognition during picture confrontation naming by contrasting gaze patterns time locked to stimulus onset. Patients included a cohort of patients with anomia associated with either primary progressive aphasia (N = 9) or Alzheimer’s disease (N = 1) who attempted to name 200 pictures over the course of 18–24 months. We retrospectively isolated correct and incorrect naming attempts and contrasted gaze patterns for accurate vs. inaccurate attempts to discern whether gaze patterns are predictive of language forgetting. Patients tended to show a lower fixation count, higher saccade count, and slower saccade velocity for items that were named incorrectly. These results hold promise for the utility of eyetracking as a diagnostic and therapeutic index of language functioning.

A Prototype for the Voice Analysis Diagnosis of Alzheimer's Disease

BACKGROUND

Speech variations enable us to map the performance of cognitive processes of syntactic, semantic, phonological, and articulatory planning and execution. Speaking is one of the first functions to be affected by neurodegenerative complaints such as Alzheimer's disease (AD), which makes the speech a highly promising biomarker for detecting the illness before the first preclinical symptoms appear.

OBJECTIVE

This paper has sought to develop and validate a technological prototype that adopts an automated approach to speech analysis among older people.

METHODS

It uses a mathematical algorithm based on certain discriminatory variables to estimate the probability of developing AD.

RESULTS AND CONCLUSION

This device may be used at a preclinical stage by non-expert health professionals to determine the likelihood of the onset of AD.

Morphometric correlates of anomia in patients with small left temporopolar lesions

Visual object naming is a complex cognitive process that engages an interconnected network of cortical regions moving from occipitotemporal to anterior-inferior temporal cortices, and extending into the inferior frontal cortex. Naming can fail for diverse reasons, and different stages of the naming multi-step process appear to be reliant upon the integrity of different neuroanatomical locations. While the neural correlates of semantic errors have been extensively studied, the neural basis of omission errors remains relatively unspecified. Although a strong line of evidence supports an association between anterior temporal lobe damage and semantic errors, there are some studies suggesting that the anterior temporal lobe could be also associated with omissions. However, support for this hypothesis comes from studies with patients in whom damage affected extensive brain regions, sometimes bilaterally. Here, we availed of a group of 12 patients with epilepsy associated with a small lesion at the tip of the left temporal pole. Using an unbiased surface-based morphometry methodology, we correlated two morphological features with errors observed during visual naming. Analyses revealed a correlation between omission errors and reduced local gyrification index in three cortical clusters: one in the left anteromedial temporal lobe region (AMTL) and two in the left anterior cingulate cortex (ACC). Our findings support the view that regions in ACC and AMTL are critical structures within a network engaged in word selection from semantics.

Differential language network functional connectivity alterations in Alzheimer's disease and the semantic variant of primary progressive aphasia

Patients with Alzheimer's disease (AD) and semantic variant primary progressive aphasia (svPPA) can present with similar language impairments, mainly in naming. It has been hypothesized that these deficits are associated with different brain mechanisms in each disease, but no previous study has used a network approach to explore this hypothesis. The aim of this study was to compare resting-state functional magnetic resonance imaging (rs-fMRI) language network in AD, svPPA patients, and cognitively unimpaired elderly adults (CTRL). Therefore, 10 AD patients, 12 svPPA patients and 11 CTRL underwent rs-fMRI. Seed-based functional connectivity analyses were conducted using regions of interest in the left anterior temporal lobe (ATL), left posterior middle temporal gyrus (pMTG) and left inferior frontal gyrus (IFG), applying a voxelwise correction for gray matter volume. In AD patients, the left pMTG was the only key language region showing functional connectivity changes, mainly a reduced interhemispheric functional connectivity with its right-hemisphere counterpart, in comparison to CTRL. In svPPA patients, we observed a functional isolation of the left ATL, both decreases and increases in functional connectivity from the left pMTG and increased functional connectivity form the left IFG. Post-hoc analyses showed that naming impairments were overall associated with the functional disconnections observed across the language network. In conclusion, AD and svPPA patients present distinct language network functional connectivity profiles. In AD patients, functional connectivity changes were restricted to the left pMTG and were overall less severe in comparison to svPPA patients. Results in svPPA patients suggest decreased functional connectivity along the ventral language pathway and increased functional connectivity along the dorsal language pathway. Finally, the observed connectivity patterns are overall consistent with previously reported structural connectivity and language profiles in these patients.

Do Alzheimer's Disease Patients Benefit From Prior-Knowledge in Associative Recognition Memory?

OBJECTIVES

Although the influence of prior knowledge on associative memory in healthy aging has received great attention, it has never been studied in Alzheimer's disease (AD). This study aimed at assessing whether AD patients could benefit from prior knowledge in associative memory and whether such benefit would be related to the integrity of their semantic memory.

METHODS

Twenty-one AD patients and 21 healthy older adults took part in an associative memory task using semantically related and unrelated word pairs and were also submitted to an evaluation of their semantic memory.

RESULTS

While participants of both groups benefited from semantic relatedness in associative discrimination, related pairs recognition was significantly predicted by semantic memory integrity in healthy older adults only.

CONCLUSIONS

We suggest that patients benefitted from semantic knowledge to improve their performance in the associative memory task, but that such performance is not related to semantic knowledge integrity evaluation measures because the two tasks differ in the way semantic information is accessed: in an automatic manner for the associative memory task, with automatic processes thought to be relatively preserved in AD, and in a controlled manner for the semantic knowledge evaluation, with controlled processes thought to be impaired in AD. (JINS, 2019, 25, 443-452).

Exploring supported conversation with familial caregivers of persons with dementia: a pilot study

Background

Dementia can lead to difficulties in communication between caregivers and patients. Teaching conversational strategies has been effective for a wide array of clients with acquired neurologic disorders and their caregivers. Research indicates positive results for Supported Conversation for adults with Aphasia (SCA) secondary to stroke. Applying this method to work with caregivers of individuals with dementia could prove to be a valid intervention tool. This investigation examined the applicability of SCA with individuals with dementia and their familial caregivers.

Method

Four dyads (caregiver and individual with dementia) participated in the SCA program with some adaptation for dementia. The program was 4 weeks with a pre-training and post training assessment. The Measure of Skill in Supported Conversation (MSC) and Measure of Level of Participation in Conversation (MPC) were given to measure the overall effectiveness of SCA at teaching and improving communication, respectively. A qualitative analysis of unproductive coping mechanisms also occurred. The Zarit Burden Interview (ZBI) was given to gauge caregiver burden from pre- to post-training.

Results

MSC and MPC scores were significantly improved from baseline to post training, and a significant reduction in unproductive coping behaviors also occured. ZBI scores were variable across participants.

Conclusions

Results suggest that the SCA has the potential to be used to improve communication between persons with dementia and their caregivers. Findings suggest that further research is warranted into the effectiveness of SCA in dementia.

Trial registration

Retrospectively registered 9/5/2018 ISRCTN17622451.

Clinical, Anatomical, and Pathological Features in the Three Variants of Primary Progressive Aphasia: A Review

Primary progressive aphasias (PPA) are neurodegenerative diseases clinically characterized by an early and relatively isolated language impairment. Three main clinical variants, namely the nonfluent/agrammatic variant (nfvPPA), the semantic variant (svPPA), and the logopenic variant (lvPPA) have been described, each with specific linguistic/cognitive deficits, corresponding anatomical and most probable pathological features. Since the discovery and the development of diagnostic criteria for the PPA variants by the experts in the field, significant progress has been made in the understanding of these diseases. This review aims to provide an overview of the literature on each of the PPA variant in terms of their clinical, anatomical and pathological features, with a specific focus on recent findings. In terms of clinical advancements, recent studies have allowed a better characterization and differentiation of PPA patients based on both their linguistic and non-linguistic profiles. In terms of neuroimaging, techniques such as diffusion imaging and resting-state fMRI have allowed a deeper understanding of the impact of PPA on structural and functional connectivity alterations beyond the well-defined pattern of regional gray matter atrophy. Finally, in terms of pathology, despite significant advances, clinico-pathological correspondence in PPA remains far from absolute. Nonetheless, the improved characterization of PPA has the potential to have a positive impact on the management of patients. Improved reliability of diagnoses and the development of reliable in vivo biomarkers for underlying neuropathology will also be increasingly important in the future as trials for etiology-specific treatments become available.

Frontotemporal stimulation modulates semantically-guided visual search during confrontation naming: A combined tDCS and eye tracking investigation

Transcranial direct current stimulation (tDCS) was paired with eye tracking to elucidate contributions of frontal, temporoparietal and anterior temporal cortex to early visual search patterns during picture naming (e.g., rapid visual scanning to diagnostic semantic features). Neurotypical adults named line drawings of objects prior to and following tDCS in three separate sessions, each employing a unique electrode montage. The gaze data revealed montage by stimulation (pre/post) interaction effects characterized by longer initial visual fixations (mean difference = 89 ms; Cohen's d = .8) and cumulative fixation durations (mean difference = 98 ms; Cohen's d = .9) on key semantic features (e.g., the head of an animal) after cathodal frontotemporal stimulation relative to the pre-stimulation baseline. We interpret these findings as reflecting a tDCS-induced modulation of semantic contributions of the anterior temporal lobe(s) to top-down influences on object recognition. Further, we discuss implications for the optimization of tDCS for the treatment of anomia in aphasia.

Semantic Feature Disturbance in Alzheimer Disease: Evidence from an Object Decision Task

BACKGROUND AND OBJECTIVE

It is widely held that semantic disturbance in Alzheimer disease (AD) involves the loss of distinctive features but the relative sparing of nondistinctive features. Many previous studies of semantic feature disturbance have used cognitively challenging tasks with verbal stimuli that allow for potential cognitive confounds. Our objective was to use a task with lower memory demands to investigate distinctive feature disturbance in AD.

METHODS

We used an object decision task to compare the processing of distinctive and nondistinctive semantic features in people with AD and age-matched controls. The task included six conditions based on the relationship between each prime and target object. We tested the processing of distinctive and nondistinctive features by selectively altering distinctive and nondistinctive semantic features between prime and target pairs.

RESULTS

Performance accuracy was significantly lower for participants with AD than for age-matched controls when distinctive features were manipulated, but no difference was found when nondistinctive features were manipulated.

CONCLUSIONS

Our results provide evidence of semantic content disturbance in AD in the context of a task with low cognitive demands.

Naming and verbal learning in adults with Alzheimer's disease, mild cognitive impairment and in healthy aging, with low educational levels

Language assessment seems to be an effective tool to differentiate healthy and cognitively impaired aging groups. This article discusses the impact of educational level on a naming task, on a verbal learning with semantic cues task and on the MMSE in healthy aging adults at three educational levels (very low, low and high) as well as comparing two clinical groups of very low (0-3 years) and low education (4-7 years) patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) with healthy controls. The participants comprised 101 healthy controls, 17 patients with MCI and 19 with AD. Comparisons between the healthy groups showed an education effect on the MMSE, but not on naming and verbal learning. However, the clinical groups were differentiated in both the naming and verbal learning assessment. The results support the assumption that the verbal learning with semantic cues task is a valid tool to diagnose MCI and AD patients, with no influence from education.

Lexical Retrieval or Semantic Knowledge? Which One Causes Naming Errors in Patients with Mild and Moderate Alzheimer's Disease?

Background

The purpose of the study was to analyze naming errors in patients with Alz­heimer's disease in comparison to healthy subjects and determine the underlying cause of naming errors in these patients.

Method

In this study, we included 35 healthy elderly subjects, 23 patients with mild Alzheimer's disease, and 23 with moderate Alzheimer's disease. Forty-five images were used to determine the type of naming errors, and to identify the underlying cause of errors, matching an image with a written word was used.

Results

Patients with Alz­heimer's disease had more naming errors compared with the group of healthy elderly, and patients with moderate Alzheimer's disease showed a slower reaction in matching an image with a written word.

Conclusion

Anomia in the initial phase of Alzheimer's disease is due to problems in lexical retrieval; however, as the disease advances, in addition to lexical retrieval problems, conceptual knowledge causes naming problems.

Lexical access in semantic variant PPA: Evidence for a post-semantic contribution to naming deficits

The most salient clinical symptom of semantic variant primary progressive aphasia (PPA) is a profound and pervasive anomia. These patients' naming impairments have been shown to reflect in large part a domain-general deterioration of conceptual knowledge that impacts both linguistic and non-linguistic processing. However, it is possible that post-semantic stages of lexical access may also contribute to naming deficits. To clarify the stages at which lexical access breaks down in semantic variant PPA, eleven French-speaking patients were asked to name objects, and were then queried for semantic, lexical-syntactic, and word form information pertaining to the items they could not name. Specifically, our goal was to determine whether patients can access intermediate representations known as lemmas, which mediate the arbitrary mapping between semantic representations and word forms (phonological and orthographic forms). The French language was chosen for this study because nouns in French are marked for grammatical gender, a prototypical type of lexical-syntactic information, represented at the level of the lemma. Access to word form information is also dependent on lemma access under some theoretical views. We found that six of the eleven patients showed partial access to either lexical-syntactic properties of unnamed items (grammatical gender), word form information (initial letter), or both. Access to these types of information suggests that a lemma has been retrieved, implying a breakdown at the post-semantic stage of word form retrieval. Our results suggest that although degraded conceptual knowledge is the main cause of naming deficits in semantic variant PPA, in some patients, a post-semantic component also contributes to the impairment.

Semantic Feature Training in Combination with Transcranial Direct Current Stimulation (tDCS) for Progressive Anomia

We examined the effectiveness of a 2-week regimen of a semantic feature training in combination with transcranial direct current stimulation (tDCS) for progressive naming impairment associated with primary progressive aphasia (N = 4) or early onset Alzheimer's Disease (N = 1). Patients received a 2-week regimen (10 sessions) of anodal tDCS delivered over the left temporoparietal cortex while completing a language therapy that consisted of repeated naming and semantic feature generation. Therapy targets consisted of familiar people, household items, clothes, foods, places, hygiene implements, and activities. Untrained items from each semantic category provided item level controls. We analyzed naming accuracies at multiple timepoints (i.e., pre-, post-, 6-month follow-up) via a mixed effects logistic regression and individual differences in treatment responsiveness using a series of non-parametric McNemar tests. Patients showed advantages for naming trained over untrained items. These gains were evident immediately post tDCS. Trained items also showed a shallower rate of decline over 6-months relative to untrained items that showed continued progressive decline. Patients tolerated stimulation well, and sustained improvements in naming accuracy suggest that the current intervention approach is viable. Future implementation of a sham control condition will be crucial toward ascertaining whether neurostimulation and behavioral treatment act synergistically or alternatively whether treatment gains are exclusively attributable to either tDCS or the behavioral intervention.

Naming unique entities in the semantic variant of primary progressive aphasia and Alzheimer's disease: Towards a better understanding of the semantic impairment

While the semantic variant of primary progressive aphasia (svPPA) is characterized by a predominant semantic memory impairment, episodic memory impairments are the clinical hallmark of Alzheimer's disease (AD). However, AD patients also present with semantic deficits, which are more severe for semantically unique entities (e.g. a famous person) than for common concepts (e.g. a beaver). Previous studies in these patient populations have largely focused on famous-person naming. Therefore, we aimed to evaluate if these impairments also extend to other semantically unique entities such as famous places and famous logos. In this study, 13 AD patients, 9 svPPA patients, and 12 cognitively unimpaired elderly subjects (CTRL) were tested with a picture-naming test of non-unique entities (Boston Naming Test) and three experimental tests of semantically unique entities assessing naming of famous persons, places, and logos. Both clinical groups were overall more impaired at naming semantically unique entities than non-unique entities. Naming impairments in AD and svPPA extended to the other types of semantically unique entities, since a CTRL>AD>svPPA pattern was found on the performance of all naming tests. Naming famous places and famous persons appeared to be most impaired in svPPA, and both specific and general semantic knowledge for these entities were affected in these patients. Although AD patients were most significantly impaired on famous-person naming, only their specific semantic knowledge was impaired, while general knowledge was preserved. Post-hoc neuroimaging analyses also showed that famous-person naming impairments in AD correlated with atrophy in the temporo-parietal junction, a region functionally associated with lexical access. In line with previous studies, svPPA patients' impairment in both naming and semantic knowledge suggest a more profound semantic impairment, while naming impairments in AD may arise to a greater extent from impaired lexical access, even though semantic impairment for specific knowledge is also present. These results highlight the critical importance of developing and using a variety of semantically-unique-entity naming tests in neuropsychological assessments of patients with neurodegenerative diseases, which may unveil different patterns of lexical-semantic deficits.

A Neuropsychological Perspective on Abstract Word Representation: From Theory to Treatment of Acquired Language Disorders

Natural languages are rife with words that describe feelings, introspective states, and social constructs (e.g., liberty, persuasion) that cannot be directly observed through the senses. Effective communication demands linguistic competence with such abstract words. In clinical neurological settings, abstract words are especially vulnerable to the effects of stroke and neurodegenerative conditions such as Alzheimer's disease. A parallel literature in cognitive neuroscience suggests that abstract and concrete words are at least partially neuroanatomically dissociable. Much remains to be learned about the nature of lexical-semantic deficits of abstract words and how best to promote their recovery. Here, we review contemporary theoretical approaches to abstract-concrete word representation with an aim toward contextualizing patient-based dissociations for abstract words. We then describe a burgeoning treatment approach for targeting abstract words and suggest a number of potential strategies for future interventions. We argue that a deeper understanding of is essential for informing language rehabilitation.

The neural correlates of anomia in the conversion from mild cognitive impairment to Alzheimer's disease

INTRODUCTION

Language impairment is frequently observed in patients with Alzheimer's disease (AD): in this study, we investigated the extent and distribution of brain atrophy in subjects with conversion from mild cognitive impairment (MCI) to AD with and without naming difficulties.

METHODS

This study was approved by the institutional review board and was HIPAA compliant. All subjects or their legal representatives gave informed consent for participation. Ninety-one subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) with (N = 51) and without (N = 40) naming impairment as per the Boston Naming Test (BNT), underwent brain magnetic resonance (MR) imaging 12 months before, at AD diagnosis, and 12 months after. Structural MR images were processed using voxel-based morphometry. Cross-sectional comparisons and mixed ANOVA models for assessing regional gray matter (GM) volume differences were performed.

RESULTS

As from 12 months prior to AD diagnosis, patients with naming difficulties showed distinct areas of greater GM loss in the left fusiform gyrus (Brodmann area 20) than patients without naming difficulties. Differences in the GM atrophy extended to the left hemisphere in the subsequent 12 months.

CONCLUSION

This study provided evidence of distinct patterns and dynamics of brain atrophy in AD patients with naming difficulties when compared to those with intact language, as early as 12 months prior to AD diagnosis and in the subsequent 12 months.

Verbal fluency, naming and verbal comprehension: three aspects of language as predictors of cognitive impairment

OBJECTIVES

To establish the possible relationship among three components of language (verbal fluency, naming and comprehension) and cognitive impairment as well as to determine the usefulness of language assessment tests to predict or monitor the development of cognitive impairment.

METHOD

A comparative, descriptive and cross-sectional study was performed on 82 subjects ≥ 65 years of age who were cognitively assessed with the Mini Mental State Examination and were divided into two groups: Group A comprised of subjects classified as levels 1, 2 and 3 on the Reisberg's Global Deterioration Scale (GDS) and group B comprised of subjects at levels 4 and 5 of the GDS. Language skills were assessed by the Verbal Fluency Test, Boston Naming Test and Token Test.

RESULTS

An inverse relationship between performance on language tests and cognitive impairment level was observed with a more pronounced effect observed on fluency and comprehension tests.

CONCLUSION

Language assessments, especially fluency and comprehension, were good indicators of cognitive impairment. The use of these assessments as predictors of the degree of cognitive impairment is discussed in-depth.

Frequency and severity of semantic deficits in a consecutive memory clinic cohort

BACKGROUND/AIM

Semantic memory deficits have been shown in dementia and mild cognitive impairment (MCI) by group comparisons. The aim of this study is to investigate the frequency of impairments on tests with semantic content in patients with dementia, MCI (amnestic and non-amnestic) and affective disorders.

METHODS

A Famous faces test, Boston Naming Test and Category fluency were applied in 114 consecutive memory clinic patients and 95 healthy participants (all participants were 60 years old or older; dementia/MCI patients had Mini-Mental State Examination scores ≥20).

RESULTS

Fifty-three patients were classified with dementia, 36 with MCI (14 amnestic, 22 non-amnestic) and 25 with affective disorders. Dementia and MCI patients differed significantly from the control group on all tests. Patients with dementia and MCI had impairments in about 40% of the cases (on the most sensitive tests). However, patients with affective disorders also had mild impairments on tests tapping semantic memory (25% were impaired on the most sensitive tests). Impairments on the Famous faces test were more frequently found in dementia and MCI as compared to patients with affective disorders.

CONCLUSION

Short tests with semantic memory content are sensitive to changes in dementia and MCI, but impairments on such tests may also be found in other diseases, e.g. affective disorders.

Automatic speech analysis for the assessment of patients with predementia and Alzheimer's disease

Background

To evaluate the interest of using automatic speech analyses for the assessment of mild cognitive impairment (MCI) and early-stage Alzheimer's disease (AD).

Methods

Healthy elderly control (HC) subjects and patients with MCI or AD were recorded while performing several short cognitive vocal tasks. The voice recordings were processed, and the first vocal markers were extracted using speech signal processing techniques. Second, the vocal markers were tested to assess their “power” to distinguish among HC, MCI, and AD. The second step included training automatic classifiers for detecting MCI and AD, using machine learning methods and testing the detection accuracy.

Results

The classification accuracy of automatic audio analyses were as follows: between HCs and those with MCI, 79% ± 5%; between HCs and those with AD, 87% ± 3%; and between those with MCI and those with AD, 80% ± 5%, demonstrating its assessment utility.

Conclusion

Automatic speech analyses could be an additional objective assessment tool for elderly with cognitive decline.

Impairment of homonymous processing in Alzheimer's disease

An important issue in research on language is how concepts are represented and associated with each other in the brain. Many investigations have focused on language ambiguity and the phenomenon of homonymy in which a single lexical item, presenting the same form, is related to different meanings. Our study aims to test the hypothesis that weak association of meaning characterizing homonyms may be especially prone to brain damage. To verify this hypothesis a test of attribution of the meaning of homonymous words, the Humpty Dumpty (HD) test, was applied to 50 patients with Alzheimer's disease (AD) and 50 healthy subjects. Results show that AD patients are impaired in the HD test in an early phase of disease and that performance correlates with naming ability and phonological fluency. The data are in keeping with a growing body of literature that supports dual impairment to the semantic system in AD, i.e., to semantic knowledge and active processing and access to the semantic field. The evaluation of the ability to resolve homonymous ambiguity, using the HD test, may provide a useful and quick clinical tool to detect the anomalies of the semantic network linked to either a loss of the core system where meaning of words is stored or an impairment of the access to an intact semantic representation.

How to constrain and maintain a lexicon for the treatment of progressive semantic naming deficits: Principles of item selection for formal semantic therapy

The progressive degradation of semantic memory is a common feature of many forms of dementia, including Alzheimer's disease and the semantic variant of primary progressive aphasia (svPPA). One of the most functionally debilitating effects of this semantic impairment is the inability to name common people and objects (i.e., anomia). Clinical management of a progressive, semantically based anomia presents extraordinary challenges for neurorehabilitation. Techniques such as errorless learning and spaced-retrieval training show promise for retraining forgotten words. However, we lack complementary detail about what to train (i.e., item selection) and how to flexibly adapt the training to a declining cognitive system. This position paper weighs the relative merits of several treatment rationales (e.g., restore vs. compensate) and advocates for maintenance of known words over reacquisition of forgotten knowledge in the context of semantic treatment paradigms. I propose a system for generating an item pool and outline a set of core principles for training and sustaining a micro-lexicon consisting of approximately 100 words. These principles are informed by lessons learned over the course of a Phase I treatment study targeting language maintenance over a 5-year span in Alzheimer's disease and SvPPA. Finally, I propose a semantic training approach that capitalises on lexical frequency and repeated training on conceptual structure to offset the loss of key vocabulary as disease severity worsens.

Abnormal dynamics of activation of object use information in apraxia: evidence from eyetracking

Action representations associated with object use may be incidentally activated during visual object processing, and the time course of such activations may be influenced by lexical-semantic context (e.g., Lee, Middleton, Mirman, Kalénine, & Buxbaum (2012). Journal of Experimental Psychology: Human Perception and Performance, 39(1), 257-270). In this study we used the "visual world" eye-tracking paradigm to examine whether a deficit in producing skilled object-use actions (apraxia) is associated with abnormalities in incidental activation of action information, and assessed the neuroanatomical substrates of any such deficits. Twenty left hemisphere stroke patients, ten of whom were apraxic, performed a task requiring identification of a named object in a visual display containing manipulation-related and unrelated distractor objects. Manipulation relationships among objects were not relevant to the identification task. Objects were cued with neutral ("S/he saw the…."), or action-relevant ("S/he used the….") sentences. Non-apraxic participants looked at use-related non-target objects significantly more than at unrelated non-target objects when cued both by neutral and action-relevant sentences, indicating that action information is incidentally activated. In contrast, apraxic participants showed delayed activation of manipulation-based action information during object identification when cued by neutral sentences. The magnitude of delayed activation in the neutral sentence condition was reliably predicted by lower scores on a test of gesture production to viewed objects, as well as by lesion loci in the inferior parietal and posterior temporal lobes. However, when cued by a sentence containing an action verb, apraxic participants showed fixation patterns that were statistically indistinguishable from non-apraxic controls. In support of grounded theories of cognition, these results suggest that apraxia and temporal-parietal lesions may be associated with abnormalities in incidental activation of action information from objects. Further, they suggest that the previously-observed facilitative role of action verbs in the retrieval of object-related action information extends to participants with apraxia.