A5031629360- Neurobiology of Language and Bilingualism
- Transcranial Magnetic Stimulation Studies
- Action Observation and Synchronization
- Stroke Rehabilitation and Recovery
- Vestibular and auditory disorders
- EEG and Brain-Computer Interfaces
- Neural and Behavioral Psychology Studies
- Reading and Literacy Development
- Spatial Neglect and Hemispheric Dysfunction
- Cerebrovascular and Carotid Artery Diseases
- Acute Ischemic Stroke Management
- Advanced Neuroimaging Techniques and Applications
- Functional Brain Connectivity Studies
- Migraine and Headache Studies
- Language Development and Disorders
- Interpreting and Communication in Healthcare
- Alzheimer's disease research and treatments
- Text Readability and Simplification
- Dementia and Cognitive Impairment Research
- Hemispheric Asymmetry in Neuroscience
- Language and cultural evolution
- Multisensory perception and integration
- Hearing Impairment and Communication
- Technology and Human Factors in Education and Health
- Motor Control and Adaptation
Johns Hopkins University
2016-2025
Johns Hopkins Medicine
2015-2024
Polymer Aging Concepts (United States)
2023
Google (United States)
2010-2022
Johns Hopkins Hospital
2017-2020
University College Dublin
2016
Calvert Memorial Hospital
2012
The University of Texas at Austin
2007-2011
Objective Many stroke patients show remarkable recovery of language after initial severe impairment, but it is difficult to predict which will good recovery. We aimed identify patient and lesion characteristics that together the best naming outcome in 4 studies. Methods report 2 longitudinal studies identified variables at onset were strongly associated with (the most common residual deficit aphasia) first 6 months stroke: damage left posterior superior temporal gyrus (pSTG) and/or...
ABSTRACT This study reports an activation likelihood estimation meta-analysis of published functional neuroimaging studies bilingualism. Four parallel meta-analyses were conducted by taking into account the proficiency participants reported in studies. The results suggest differences probabilities patterns between high and moderate/low bilinguals. Talairach coordinates first language processing very similar to that second proficient However, low group, clusters generally smaller distributed...
People with post-stroke aphasia may have some degree of chronic deficit for which current rehabilitative treatments are variably effective. Accumulating evidence suggests that transcranial direct stimulation (tDCS) be useful enhancing the effects behavioral treatment. However, it remains unclear brain regions should stimulated to optimize on language recovery. Here, we report therapeutic potential right cerebellar tDCS in augmenting recovery SMY, who sustained bilateral MCA infarct resulting...
Introduction: Aphasia is a debilitating language disorder and even mild forms of aphasia can negatively affect functional outcomes, mood, quality life, social participation, the ability to return work. Language deficits after post-stroke are heterogeneous. Areas covered: The first part this manuscript reviews traditional syndrome-based classification approach as well recent advances in that incorporate automatic speech recognition for classification. second behavioral approaches treatment...
Abstract Transcranial direct current stimulation has been shown to increase the efficiency of language therapy in chronic aphasia; however, date, an optimal site not identified. We investigated whether neuromodulation right cerebellum can improve naming skills aphasia. Using a randomized, double-blind, sham-controlled, within-subject crossover study design, participants received anodal cerebellar (n = 12) or cathodal + computerized aphasia then sham therapy, opposite order. There was no...
The "language network" is remarkably stable across language tasks but changes in response to injury specific components or "disconnection" of input one component. We investigated network during recovery, hypothesizing that recovery takes place through distinct mechanisms: (a) reperfusion; (b) from diaschisis; (c) structural disconnection; and (d) "reorganization" language, whereby various assume function a damaged also tested the hypothesis depends on: task, level performance, size site...
The National Institutes of Health Stroke Scale (NIHSS) includes minimal assessment cognitive function, particularly in right hemisphere (RH) stroke. Descriptions the Cookie Theft picture from NIHSS allow analyses that (1) correlate with aphasia severity and (2) identify communication deficits RH We hypothesized analysis description contributes valuable information about volume location acute stroke.We evaluated 67 patients ischemic stroke (34 left [LH]; 33 RH) NIHSS, picture, magnetic...
Abstract Lesion‐symptom mapping is an important method of identifying networks brain regions critical for functions. However, results might be influenced substantially by the imaging modality and timing assessment. We tested hypothesis that found to associated with acute language deficits depend on (1) behavioral measurement, (2) sequences utilized define “lesion” (structural abnormality only or structural plus perfusion abnormality), (3) power study. studied 191 individuals left hemisphere...
Purpose:The neural mechanisms that support aphasia recovery are not yet fully understood.Our goal was to evaluate longitudinal changes in naming participants with posterior cerebral artery (PCA) stroke using a case-by-case analysis.Methods: Using task based and resting state functional magnetic resonance imaging (fMRI) detailed language testing, we longitudinally studied the of network four PCA deficits at acute (0 week), sub (3-5 weeks), chronic time point (5-7 months) post...
Background: Individuals with primary progressive aphasia (PPA) and their caregivers want to know what expect so that they can plan support appropriately. The ability predict decline in naming semantic knowledge, advise individuals PPA regarding future planning, would be invaluable clinically.Aims: aims of this study were investigate patterns knowledge each the clinical variants (logopenic variant PPA, lvPPA; nonfluent agrammatic nfaPPA; svPPA) examine effects other variables on rate decline....
<h3>Objective</h3> To test the hypothesis that severity of leukoaraiosis in noninfarcted hemisphere at onset is associated with poorer language outcome after poststroke aphasia independently volume infarct, damage to 3 critical areas (left inferior frontal gyrus, superior longitudinal fasciculus, and temporal gyrus), comorbid conditions, time since stroke. <h3>Methods</h3> In this cross-sectional study, we evaluated naming (>3 months stroke) 42 individuals who initially had We rated right...
Transcranial direct-current stimulation (tDCS) is a promising adjunct to therapy for chronic aphasia.
We evaluated the hypothesis that Brodmann's area (BA) 37 within left occipitotemporal cortex has at least two important functions in lexical processing. One role is computation of case-, font-, location-, and orientation-independent grapheme descriptions for written word recognition production (reading spelling). This may depend on medial part BA 37, midfusiform gyrus. The second accessing modality-independent representations output, naming reading spelling irregular or exception words....
Although aphasia and hemispatial neglect are classically labeled as cortical deficits, language deficits or following lesions to subcortical regions have been reported in many studies. However, whether not can be caused by alone has a matter of controversy. It previously shown that most cases due acute non-thalamic infarcts accounted for concurrent hypoperfusion arterial stenosis occlusion, reversible restoring blood flow the cortex. In this study we evaluated occur after thalamic infarct...
Background and Purpose— Stroke is the leading cause of disability in United States, aphasia a common sequela after left hemisphere stroke. Functional imaging brain stimulation studies show that right structures are detrimental to recovery but evidence from diffusion tensor lacking. We investigated role homologous language pathways naming hemispheric Methods— Patients with stroke underwent assessment using Boston Naming Test at acute chronic time points. analyzed arcuate fasciculus frontal...
Naming impairment is commonly noted in individuals with aphasia. However, object naming receives more attention than action naming. Furthermore, most studies include participants aphasia due to only one aetiology, stroke. We developed a new assessment, the Hopkins Action Assessment (HANA), evaluate impairments.Our aims were show that HANA useful tool can (1) identify impairments and (2) be used investigate neural substrates underlying paired Boston Test (BNT) compare considered primary...
Purpose Kiran and colleagues (Kiran, 2007, 2008; & Johnson, Thompson, 2003) previously suggested that training atypical examples within a semantic category is more efficient treatment approach to facilitating generalization the than typical examples. In present study, authors extended previous work examining notion of complexity goal-derived (ad hoc) categories in individuals with aphasia. Methods Six fluent aphasia (age range = 39–84 years) varying degrees naming deficits impairments...
Background: Neuroimaging research on language recovery in patients with aphasia due to left hemisphere damage has generated some intriguing results. However, it is still not clear what role the right plays supporting recovered functions chronic phase for different site and size of lesion when tasks are used. Aims: The present study aimed at exploring perilesional, ipsilesional, contralesional activation participants using two tasks. All were stage well- or significant improvements functions....
The insula has been implicated in many sequelae of stroke. It is the area most commonly infarcted people with post-stroke arrhythmias, loss thermal sensation, hospital acquired pneumonia, and apraxia speech. We hypothesized that some these results reflect fact that: (1) ischemic strokes involve are larger than exclude (and therefore associated more common persistent deficits); (2) insular involvement a marker middle cerebral artery (MCA) occlusion. analyzed MRI scans 861 patients acute...
Background: Previous studies utilized lesion-centric approaches to study the role of thalamus in language. In this study, we tested hypotheses that non-lesioned dorsomedial and ventral anterior nuclei (DMVAC) pulvinar lateral posterior complexes (PLC) their projections left hemisphere show secondary effects strokes, microstructural integrity is closely related language-related functions. Methods: Subjects with language impairments after a left-hemispheric cortical and/or subcortical, early...
Background: Three variants of primary progressive aphasia (PPA), distinguished by language performance and supportive patterns atrophy on imaging, have different clinical courses the prognoses for specific functions. For example, semantic variant PPA alone is impaired word comprehension. However, sometimes individuals with high education show normal word-comprehension tests early on, making classification difficult. Furthermore, as condition progresses, other develop deficits behavioural...