Simona Brambati

Université de Montréal | UdeM · Department of Psychology

This article has been accepted for publication in the American Journal of Speech-Language Pathology (August 12th 2021) Abstract The main aim of the current study is to provide French-Canadian reference data for quantitative measures extracted from connected speech samples elicited by the Western Aphasia Battery-Revised (WAB-R) Picnic scene, a disc...

Older adults display impairments in accessing episodic, but not semantic details, when specifically requested to construct autobiographical events. How aging affects access to autobiographical information under conditions of low retrieval constraint remains unclear. We examined the production of episodic and “non-episodic” details in young (n = 25)...

A longitudinal study of narrative discourse in post-stroke aphasia

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Objective: The concepts of mild cognitive impairment (MCI) and subjective cognitive decline (SCD) have been proposed to identify individuals in the early stages of Alzheimer's disease (AD), or other neurodegenerative diseases. One approach to validate these concepts is to investigate the relationship between pathological brain markers and cognitio...

Background: Discourse analysis allows the examination of functional and ecological language impairment in post-stroke aphasia. Given its complexity, various methods of analysis have been developed to measure the multiple components of discourse. Clinical assessment usually includes discourse analysis, but how clinicians should assess recovery of di...

Background: The greatest degree of language recovery in post-stroke aphasia takes place within the first weeks. Aphasia severity and lesion measures have been shown to be good predictors of long-term outcomes. However, little is known about their implications in early spontaneous recovery. The present study sought to determine which factors better...

Background: Persons with Subjective Cognitive Decline (SCD) complain about their memory, but perform within normal ranges on standard neuropsychological tests. It has been proposed that these individuals might be in a very early phase of Alzheimer’s disease (AD). However, SCD is a recent classification and it represents a heterogeneous group of ind...

Posterior cortical atrophy (PCA) is a neurodegenerative disease affecting the posterior region of the brain. Little is known about both the impact of PCA on functioning and how to support patients on a daily basis. The purpose of this study was to describe the functional profile of DD, a woman diagnosed with PCA, as well as to explore a pilot cogni...

Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international tractography challenge, which resulted in 96 distinct su...

The aim of this study was to investigate the comprehension of concrete, abstract and abstract emotional words in semantic variant primary progressive aphasia (svPPA), Alzheimer’s disease (AD), and healthy elderly adults (HE) Three groups of participants (9 svPPA, 12 AD, 11 HE) underwent a general neuropsychological assessment, a similarity judgment...

Hippocampal atrophy is one of the anatomical hallmarks in Alzheimer’s disease (AD) patients and the substrate of their episodic memory deficits. However, its specificity has been questioned since semantic dementia (SD) patients also display an atrophy of the hippocampus, but the cognitive symptoms do not include episodic memory impairments, and the...

Idiopathic rapid eye movement sleep behavior disorder (iRBD) is a major risk factor for Parkinson's disease and dementia with Lewy bodies. Anatomical gray matter abnormalities in the motor cortico-subcortical loop areas remain under studied in iRBD patients. We acquired T1-weighted images and administrated quantitative motor tasks in 41 patients wi...

The anterior temporal lobes (ATLs) have been consistently associated with semantic processing which, in turn, has a key role in reading aloud single words. This study aimed to investigate (1) the reading abilities in patients with the semantic variant of primary progressive aphasia (svPPA), and (2) the relationship between gray matter (GM) volume o...

Primary progressive aphasia (PPA) is a heterogeneous neurodegenerative condition in which the most prominent clinical feature is language difficulties. Other cognitive domains have been described to remain unaffected at the early stages of the disease and, therefore, excluded from diagnostic criteria. However, we show in this article that executive...

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) tha...

Fiber tractography based on non-invasive diffusion imaging is at the heart of connectivity studies of the human brain. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain dataset with ground truth white matter tracts, we organized an open international tractography challenge, which r...

Poster presented in French for the JEV 2016

Cognitive and computational models of reading aloud agree on the existence of two procedures for reading. Pseudowords (e.g., atendier) are correctly read through subword processes only while exception words (e.g., pint) are only correctly read via whole-words processes. Regular words can be correctly read by means of either way. Previous behavioral...

Background/Objectives. Alzheimer’s disease (AD) and semantic dementia (SD) have distinct episodic memory profiles despite the hippocampal atrophy that characterizes both diseases. The aim of this study was to delineate the pattern of gray matter (GM) atrophy associated with AD and SD as well as any differences in these patterns by pooling together...

The ability to recognize a famous person occurs through semantic memory. Previous neuroimaging studies have shown that the anterior temporal lobes (ATLs) are involved in the recognition of famous people. However, it is still a matter of debate whether the semantic processing of names or pictures of famous people has an impact on the activation of A...

*The 3 first authors contributed equally to the work* La maladie d’Alzheimer (MA) est une maladie neurodégénérative, caractérisée par une atrophie au niveau de l’hippocampe, qui entraîne des altérations significatives et progressives de la mémoire épisodique. La MA affecte les fonctions cognitives, provocant des modifications comportementales affec...

The co-occurrence of semantic impairment and surface dyslexia in the semantic variant of primary progressive aphasia (svPPA) has often been taken as supporting evidence for the central role of semantics in visual word processing. According to connectionist models, semantic access is needed to accurately read irregular words. They also postulate tha...

Objectif: Cette étude évalue si des connaissances concrètes, abstraites, et émotionnelles sont atteintes de manière différente dans la démence sémantique. Méthodologie: 9 patients souffrant de démence sémantique (DS), 12 patients souffrant de la maladie d’Alzheimer (MA) et 11 personnes âgées contrôles ont complété une tâche d’appariement sémantiqu...

L’IRM de diffusion profite des caractéristiques de la diffusion des molécules d’eau dans le cerveau afin de déterminer les faisceaux de matière blanche. L’analyse de la matière blanche et des connexions entre les régions cérébrales devient un aspect essentiel en recherche clinique et fondamentale. Ce domaine émergeant reste néanmoins peu accessible...

Background Successful reading can be achieved by means of two different procedures: sub‐word processes for the pronunciation of words without semantics or pseudowords (PW) and whole‐word processes that recruit word‐specific information regarding the pronunciation of words with atypical orthography‐to‐phonology mappings (exception words, EW). Metho...

Clinical symptoms observed in Alzheimer's disease (AD) patients may reflect variations within specific large-scale brain networks, modeling AD as a disconnection syndrome. The present magnetic resonance imaging study aims to compare the organization of gray matter structural covariance networks between 109 cognitively unimpaired controls (CTRL) and...

The present study investigated the pattern of longitudinal changes in cognition and anatomy in three variants of primary progressive aphasia (PPA). Eight patients with the non-fluent variant of PPA (nfvPPA), 13 patients with the semantic variant (svPPA), seven patients with the logopenic variant (lvPPA), and 29 age-matched, neurologically healthy c...

Relying on procedural memory is a promising approach for interventions that address the cognitive difficulties found in semantic dementia. The aim of this study was to determine if procedural memory could be used to optimise learning of relevant smartphone functions in MH, a 55-year-old man with semantic dementia. The impact of learning to use spec...

We aimed to characterize difficulties in famous face naming in three poststroke aphasic patients with a lesion limited to the left mid-posterior temporal language regions, sparing the anterior temporal lobe. The patients did not present semantic deficits specific to known people. Nonetheless, they showed difficulties naming famous buildings in addi...

Introduction According to its classic definition, the morpheme is the smallest meaning unit of language. Accessing the meaning of derivational morphemes helps to understand new or unfamiliar words. The aim of this study was to explore the impact of semantic impairment on the comprehension of derivational morphemes in a group of individuals with sem...

Idiopathic rapid eye movement sleep behavior disorder is a parasomnia that is a risk factor for dementia with Lewy bodies and Parkinson's disease. Brain function impairments have been identified in this disorder, mainly in the frontal and posterior cortical regions. However, the anatomical support for these dysfunctions remains poorly understood. W...

Objective: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects the corpus callosum (CC), which plays a key role in interhemispheric coupling in high-demand conditions. Using 3D callosal measurements and a letter-matching paradigm, this 2-part study investigated the neural substrate of interhemispheric coupling in indiv...

Semantic deficits in Alzheimer's disease (AD) are often more severe for items that are characterized by a unique semantic and lexical association, such as famous people. Whether these deficits are due to the degradation of semantic information or a deficit in the ability to intentionally access semantic knowledge remains controversial. To assess th...

Previous anatomical volumetric studies have shown that healthy aging is associated with gray matter tissue loss in specific cerebral regions. However, these studies may have potentially missed critical elements of age-related brain changes, which largely exist within interrelationships among brain regions. This magnetic resonance imaging research a...

To compare music recognition in patients with frontotemporal dementia, semantic dementia, Alzheimer disease, and controls and to evaluate the relationship between music recognition and brain volume. Recognition of familiar music depends on several levels of processing. There are few studies about how patients with dementia recognize familiar music....

Growing evidence indicates that individuals with Mild Cognitive Impairment (MCI) manifest semantic deficits that are often more severe for items that are characterized by a unique semantic and lexical association, such as famous people and famous buildings, than common concepts, such as objects. However, it is still controversial whether the semant...

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke's aphasia (WA) due to stroke. We compared 10...

Neuroimaging studies on healthy subjects have reported the involvement of the bilateral anterior temporal lobes (ATL) in recognizing known people. While the role of the right ATL in the semantic processing of known people is accepted, it is still matter of debate whether left ATL is implicated in the name retrieval or in the access to semantic info...

Modern cognitive neuroscientific theories and empirical evidence suggest that brain structures involved in movement may be related to action-related semantic knowledge. To test this hypothesis, we examined the naming of environmental sounds in patients with corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP), two neurodegenerat...

Obsessive–compulsive disorder (OCD) is thought to involve large-scale brain systems but the anatomical connectivity via association fibers has not been specifically investigated yet.We evaluated organization and directionality of the major fiber bundles in a subpopulation of OCD, including washers and checkers who presented decision making deficits...

Idiopathic Parkinson's disease (PD) is a neurodegenerative disorder characterized by the dysfunction of dopaminergic dependent cortico-basal ganglia loops and diagnosed on the basis of motor symptoms (tremors and/or rigidity and bradykinesia). Post-mortem studies tend to show that the destruction of dopaminergic neurons in the substantia nigra cons...

Amnestic mild cognitive impairment (aMCI) is considered a transition stage between normal aging and Alzheimer's disease (AD). Two main clinical subtypes of aMCI have been identified: (1) single-domain aMCI (aMCI-SD), with isolated episodic memory impairments, and (2) multiple-domain aMCI (aMCI-MD), with episodic memory impairments and deficits in o...

Semantic deficits in Alzheimer's disease have been widely documented, but little is known about the integrity of semantic memory in the prodromal stage of the illness. The aims of the present study were to: (i) investigate naming abilities and semantic memory in amnestic mild cognitive impairment (aMCI), early Alzheimer's disease (AD) compared to h...

Cognitive deficits in semantic dementia have been attributed to anterior temporal lobe grey matter damage; however, key aspects of the syndrome could be due to altered anatomical connectivity between language pathways involving the temporal lobe. The aim of this study was to investigate the left language-related cerebral pathways in semantic dement...

Previous neuropsychological studies on acquired dyslexia revealed a double dissociation in reading impairments. Patients with phonological dyslexia have selective difficulty in reading pseudo-words, while those with surface dyslexia misread exception words. This double dissociation in reading abilities has often been reported in brain-damaged patie...

To investigate the neural correlates of verbal and nonverbal semantic processing in neurodegenerative disease. Semantic memory is often impaired in neurodegenerative disease. Neuropsychologic and functional neuroimaging studies suggest that the semantic processing of verbal and nonverbal stimuli may depend on partially distinct brain networks. We e...

Good cognitive performance requires adherence to rules specific to the task at hand. Patients with neurological disease often make rule violation (RV) errors, but the anatomical basis for RV during cognitive testing remains debated. The present study examined the neuroanatomical correlates of RV errors made on tests of executive functioning in 166...

Though neuroimaging, pathology and pathophysiology suggest a subcortical and deep cortical involvement in Frontotemporal Lobar Degeneration (FTLD), no studies have comprehensively assessed the associated gray matter (GM) volume changes. We measured caudate, putamen, thalamus, and amygdala GM volume using probabilistic a-priori regions of interest (...

Semantic dementia (SD) is a neurodegenerative disease characterized by atrophy of anterior temporal regions and progressive loss of semantic memory. SD patients often present with surface dyslexia, a relatively selective impairment in reading low-frequency words with exceptional or atypical spelling-to-sound correspondences. Exception words are typ...

Primary progressive aphasia (PPA) is characterized by isolated decline in language functions. Semantic dementia and progressive nonfluent aphasia are accepted PPA variants. A "logopenic" variant (LPA) has also been proposed, but its cognitive and anatomic profile is less defined. The aim of this study was to establish the cognitive and anatomic fea...

Data on white matter changes in corticobasal degeneration syndrome (CBDS) are not yet available, whereas cortical gray matter loss is a feature of this condition. The structural abnormalities related to a key feature of CBDS (limb apraxia) are unknown. To measure selective structural changes in early CBDS using diffusion tensor imaging and voxel-ba...

Patterns of language impairment have long been used clinically to localize brain damage in stroke patients. The same approach might be useful in the differential diagnosis of progressive aphasia owing to neurodegenerative disease. To investigate whether scores on 4 widely used language tasks correlate with regional gray matter loss in 51 patients w...

One of the most remarkable abilities of bilinguals is to produce and/or to perceive a switch from one language to the other without any apparent difficulty. However, several psycholinguistic studies indicate that producing, recognizing, and integrating a linguistic code different from the one in current use may entail a processing cost for the spea...

Progressive nonfluent aphasia (PNFA) is a clinical syndrome characterized by motor speech impairment and agrammatism, with relative sparing of single word comprehension and semantic memory. PNFA has been associated with the characteristic pattern of left anterior insular and posterior frontal atrophy, including the motor and premotor regions and Br...

This study investigates whether sentence comprehension and nonsyntactic verbal working memory (vWM) are sustained by the same or by different neural systems. Scores in a sentence-picture matching task and in digits backward (DB) were correlated with magnetic resonance imaging voxelwise gray matter volumes using voxel-based morphometry in 58 patient...

We performed a longitudinal anatomical study to map the progression of gray matter atrophy in anatomically defined predominantly left (LTLV) and right (RTLV) temporal lobe variants of semantic dementia (SD). T1-weighted MRI scans were obtained at presentation and one-year follow-up from 13 LTLV, 6 RTLV, and 25 control subjects. Tensor-based morphom...

Frontotemporal dementia (FTD) is a neurodegenerative disease characterized by progressive behavioural abnormalities and frontotemporal atrophy. Here we used tensor based morphometry (TBM) to identify regions of longitudinal progression of gray matter atrophy in FTD compared to controls. T1-weighted MRI images were acquired at presentation and 1-yea...