A5022642288- Neurobiology of Language and Bilingualism
- EEG and Brain-Computer Interfaces
- Transcranial Magnetic Stimulation Studies
- Multisensory perception and integration
- Spatial Neglect and Hemispheric Dysfunction
- Advanced Neuroimaging Techniques and Applications
- Acute Ischemic Stroke Management
- Action Observation and Synchronization
- Neuroscience and Music Perception
- Functional Brain Connectivity Studies
- Dementia and Cognitive Impairment Research
- Reading and Literacy Development
- Hearing Loss and Rehabilitation
- Vestibular and auditory disorders
- Tactile and Sensory Interactions
- Stroke Rehabilitation and Recovery
- Migraine and Headache Studies
- Artificial Intelligence in Healthcare and Education
- Cerebrovascular and Carotid Artery Diseases
- S100 Proteins and Annexins
- Advanced MRI Techniques and Applications
- Alzheimer's disease research and treatments
- Plant-based Medicinal Research
University of South Carolina
2020-2025
University of Delaware
2023-2024
Johns Hopkins University
2019-2021
Johns Hopkins Medicine
2019-2021
Neurology, Inc
2020
The neural basis of language has been studied for centuries, yet the networks critically involved in simply identifying or understanding a spoken word remain elusive. Several functional-anatomical models critical substrates receptive speech have proposed, including (1) auditory-related regions left mid-posterior superior temporal lobe, (2) motor-related frontal lobe (in normal and/or noisy conditions), (3) anterior (4) bilateral areas. One difficulty comparing these is that they often focus...
Abstract We investigated the ability of 40 left-hemisphere brain-lesioned individuals with various diagnoses aphasia to temporally synchronize audio a spoken word its congruent video using maximum-likelihood adaptive psychophysical procedure. found statistically significant effect type, not explained by lesion volume, on measures audiovisual (AV) synchrony. Brain-lesioned no symptoms aphasia, and those conduction performed synchrony task more similarly age-matched neurotypical controls,...
To determine whether right ventral stream and limbic structures (including posterior superior temporal gyrus [STG], STG, pole, inferior frontal pars orbitalis, orbitofrontal cortex, amygdala, anterior cingulate, gyrus, the sagittal stratum) are implicated in emotional prosody identification.Patients with MRI scans within 48 hours of unilateral hemisphere ischemic stroke were enrolled. Participants presented 24 sentences neutral semantic content spoken happy, sad, angry, afraid, surprised, or...
Transcranial direct-current stimulation (tDCS) is a promising adjunct to therapy for chronic aphasia.
A clinical diagnosis of primary progressive aphasia relies on behavioral characteristics and patterns atrophy to determine a variant: logopenic; nonfluent/agrammatic; or semantic. The dual stream model (Hickok & Poeppel, 2000; 2004; 2007; 2015) is contemporary paradigm that has been applied widely understand brain-behavior relationships; however, applications neurodegenerative diseases like are limited.
While language characteristics of logopenic variant primary progressive aphasia (lvPPA) are well-defined, behavioral less understood. We investigated correlations between and scores across three variants (PPA) found performance disturbances correlated in lvPPA, but not other PPA subtypes. Results suggest that unlike variants, patients diagnosed with lvPPA do develop negative behaviors until deficits severe. This is consistent the underlying neuropathology Alzheimer's Disease. Such findings...
Background: It is estimated that ∼30% of stroke survivors have aphasia, a language disorder resulting from damage to left-hemisphere networks. In acute care settings, efficient identification aphasia critical, but there paucity bedside assessments. Objective: To determine whether objective measures on picture description task administered within 48 hours post (a) predict recovery, (b) estimate lesion volume and location, (c) correlate with other Method: Behavioral data were scored at chronic...
Speech entrainment (SE), the online mimicking of an audio-visual speech model, has been shown to increase fluency in individuals with non-fluent aphasia. One theory that may explain why SE improves output is it synchronizes functional connectivity between anterior and posterior language regions be more similar neurotypical speakers.The present study tested this by measuring 2 necessary for production, their right hemisphere homologues, 24 persons aphasia compared 20 controls during both free...
Abstract Auditory stream segregation and informational masking were investigated in brain-lesioned individuals, age-matched controls with no neurological disease, young college-age students. A psychophysical paradigm known as rhythmic release (RMR) was used to examine the ability of participants identify a change sequence 20-ms Gaussian noise bursts presented through headphones filtered generalized head-related transfer functions produce percept an externalized auditory image (i.e., 3D...
Background: The rate of decline in language primary progressive aphasia (PPA) is highly variable and difficult to predict at baseline. severity diffuse white matter disease (leukoaraiosis), a marker overall brain health, may substantially influence the decline.Aims: To test hypothesis that leukoaraiosis associated with steeper naming PPA.Methods procedures: In this longitudinal, observational study, 29 individuals PPA (all variants) were administered Boston Naming Test (BNT) baseline 1 year...
Purpose The objectives of this study are to (a) identify speech-language pathologists' (SLPs') familiarity with transcranial direct current stimulation (tDCS), (b) quantify what SLPs consider necessary tDCS-related improvement in aphasia severity (i.e., tDCS enhancement; desired above and beyond traditional behavioral therapy) implement adjuvant therapy for the clinical management aphasia, (c) concerns that could potentially hinder adoption tDCS. Method A brief (14-question) survey was...
Abstract The neural basis of language has been studied for centuries, yet the networks critically involved in simply identifying or understanding a spoken word remain elusive. Several functional-anatomical models critical substrates receptive speech have proposed, including (1) auditory-related regions left mid-posterior superior temporal lobe, (2) motor -related frontal lobe (in normal and/or noisy conditions), anterior (4) bilateral areas. One difficulty comparing these is that they often...
Altered functional connectivity is related to severity of language impairment in poststroke aphasia. However, it not clear whether this finding specifically reflects loss coherence, or more generally, decreased structural due cortical necrosis. The aim the current study was investigate issue by factoring out from measures and then relating residual data performance poststroke. Ninety-seven participants with a history stroke were assessed using (Auditory Verbal Comprehension Spontaneous...
Background Transcranial direct current stimulation (tDCS) has emerged as a possible neuromodulatory tool to augment language therapy in post-stroke aphasia. However, there is limited information on whether tDCS may help improve everyday functional communication.
The dual-stream model of speech processing describes a cortical network involved in processing. However, it is not yet known if the represents actual intrinsic functional brain networks. Furthermore, unclear how disruptions after stroke to connectivity model's regions are related production and comprehension impairments seen aphasia. To address these questions, present study, we examined two independent resting-state fMRI data sets: (1) 28 neurotypical matched controls (2) chronic...
Event Abstract Back to Cookie Theft Picture Description: Linguistic and Neural Correlates Lynsey M. Keator1*, Shannon Sheppard1, Andreia V. Faria2, Kevin Kim1, Sadhvi Saxena1, Amy Wright1 Argye E. Hillis1, 2, 3, 4 1 Johns Hopkins Medicine, Neurology, United States 2 University, The Russell H Morgan Department of Radiology Radiological Science, 3 Physical Medicine Rehabilitation, Cognitive Problem/Hypothesis: Expressive language deficits, such as word finding, are common following a stroke...
The dual-stream model of speech processing has been proposed to represent the cortical networks involved in comprehension and production. Although it is arguably prominent neuroanatomical processing, not yet known if represents actual intrinsic functional brain networks. Furthermore, unclear how disruptions after a stroke connectivity model's regions are related specific types production impairments seen aphasia. To address these questions, present study, we examined two independent...
Event Abstract Back to Neural Correlates of Sentence Comprehension Recovery – A Longitudinal Study Shannon M. Sheppard1*, Kevin Kim1, Lynsey Keator1, Bonnie L. Breining1, Donna C. Tippett1, 2, 3 and Argye E. Hillis1, 4 1 Johns Hopkins Medicine, Department Neurology, United States 2 Physical Medicine & Rehabilitation, University, Otolaryngology—Head Neck Surgery, Cognitive Science, Introduction Left-hemisphere (LH) damage following stroke often results in sentence comprehension impairments....