Current Research Projects
Current research activity by affiliated researchers of the Harold Goodglass Aphasia Research Center consists of 24 research projects including 14 R01s. A brief description of some of these projects follows.
Speech and Language Processing in Aphasia
Sheila Blumstein, Brown University
The broad goal of this research program is to provide a window into those aspects of the cognitive architecture of the lexical processing system that are impaired and those that are spared in aphasia and to examine the neural systems underlying such processing. Our focus is on lexical processing and the effects of competition on mapping from sound to meaning in auditory word recognition and on mapping from meaning to sound in spoken word production.The focus is on lexical processing and the effects of competition on mapping from sound to meaning in auditory word recognition and on mapping from meaning to sound in spoken word production. Please visit Dr. Blumstein's lab website.
Word Retrieval in Aphasia
Arthur Wingfield, Brandeis University
Dr. Wingfield’s project in the Brandeis University Memory and Cognition Laboratory examines questions relating to speech production and its implications for memory retrieval. In one approach to this question, they explore various types of naming deficits fololwing left hemisphere focal brain damage, primarily stroke. The ongoing projects are investigating the effect of different forms of brain injury on language comprehension and production. By examining language abilities in people with specific brain injuries, a better understanding of how these areas function in non-injured adults is gained.
Metaphor Training Project
Hiram Brownell, Boston College and Kristine Lundgren, Boston University
This project addresses an important gap in the clinical literature: the dearth of tools for remediation of the communication deficits associated with brain damage caused by stroke in the right cerebral hemisphere and by traumatic brain injury. Many patients with these types of injuries exhibit a range of communication impairments with non literal language that impact their lives in negative ways. The protocol is designed to evaluate and remediate: 1) difficulty generating appropriate associations to words; 2) difficulty evaluating connotative shared meaning; and 3) difficulty selecting from among alternative interpretations. The protocol examines what specifically changes during training and the impact of the intensity of training on the duration and generalizability of gains. In addition, the protocol assesses the fading of treatment gains over time and will explore approaches to slowing or preventing that decline.
Language in the Aging Brain
Martin Albert and Loraine Obler, Boston University
In our current research, we seek to explain changes in lexical retrieval and auditory comprehension - language domains we know to change in healthy older adults. Our principal research question is: To what extent do health and cognition account for age-related changes in language? For more information, please visit the website for the Language and Aging Brain project.
Transcranial Magnetic Stimulation to Improve Speech Project
Margaret Naeser, Boston VA Healthcare System and Boston University
This study investigates whether repetitive transcranial magnetic stimulation (rTMS) can be used to improve speech in chronic stroke patients with nonfluent aphasia. The rTMS procedure allows painless, non-invasive stimulation of human cortex (1 cm x 1 cm). Slow (1 Hz) rTMS appears to decrease excitability in the targeted cortical region of interest (ROI) leading to measurable behavioral effects. Data from functional neuroimaging studies suggest that impaired modulation of right (R) perisylvian homologous language areas may be a contributing factor to nonfluent speech in aphasia. Patients with nonfluent speech have excess blood flow (presumed abnormal increase in cortical excitability) in R perisylvian homologous language areas including in part, R Broca's area (pars triangularis, Brodmann area, BA 45, and pars opercularis, BA 44); R sensorimotor cortex-mouth and R Wernicke's (BA 22) (Belin et al., 1996; Lindfield et al., 1999; Rosen et al., 2000; Naeser et al., submitted). It is hypothesized that suppression of activity in the directly targeted ROI will have an overall modulating effect on functionally connected elements of the distributed neural network for naming (and propositional speech) and will result in a behavioral improvement.
Please visit Dr. Naeser’s lab website.
Neural Networks and Language Recovery in Aphasia from Stroke” FMRI Studies
Margaret Naeser, Boston VA Healthcare System and Boston University
The major goal of this four-year research project is to utilized functional magnetic resonance imagihg (FMRI)to investigate brain reorganization for language behavior in chronic stroke patients with aphasia. Patients are studies with fMRI paradigms for Overt Propositional Speech fMRI; and Nonverbal Semantic Decision FMRI before and after a series of real or sham TMS treatments.
Please visit Dr. Naeser’s lab website.
Cognitive Neuroscience of Visual Imagery: fMRI and TMS Studies
Stephen M. Kosslyn (UCLA)
Visual mental memory is used in memory, reasoning, and learning. A deeper understanding of the nature of imagery has practical implications for the diagnosis and treatment of a variety of neuropsychological conditions. The general goal of this research is to conduct functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies to investigate the representations and processes that underlie visual mental imagery.
Neural Modeling and Imaging of Speech and Sequencing and Initiation in Speech Production
Frank Guenther, Boston University
The primary goal of this research project is the continued development, testing, and a refinement of a comprehensive computational modeling framework addressing the neural processes underlying speech perception and production. This framework is defined using adaptive neural networks, allowing comparisons with data from imaging studies of brain function. Please visit Dr. Guenther's lab website.
Aphasic Comprehension of Raising and Passive Constructions
Ken Wexler, Massachusetts Institute of Technology
This project investigates the grammatical comprehension of passives and raising constructions in aphasic patients to better understand how language therapy should be designed. This research attempts to better characterize the linguistic difficulties stemming from neurological damage related to aphasia.
Please visit Dr. Wexler’s lab website.
