Translational Research on Speech and Language may Lead to Improved Post-Stroke Aphasia Therapy
Sheila Blumstein, Ph.D.
Brown University, Providence, RI, Department of Cognitive and Linguistic Sciences
Clinical Neuroscience Research
December 2012, for 3 years
Translational research on speech and language may lead to improved post-stroke aphasia therapy
This pilot study will explore the potential efficacy of a targeted speech therapy program in improving speech sounds and ultimately communication by patients who developed aphasia as a result of a stroke.
Stroke-induced injuries to the brain can result in aphasia, creating deficits in producing and in comprehending speech and language. One of the residual clinical features in many patients is the inability to produce single words clearly, often distorting the sounds of speech or producing them incorrectly, or to string words together to form sentences. While current rehabilitation programs attempt to help patients improve in naming words and producing language, none focuses on phonetics—the quality of pronunciation sounds—to improve production of words and sentences to ultimately enhance communication. Patients with “non-fluent” aphasia typically have injury to anterior brain structures (inferior frontal gyrus, IFG); they not only have limited speech but also difficulty articulating language sounds, producing distorted and hard to understand language. Patients with injury to the supramarginal gyrus (SMG) usually are fluent but select the wrong sounds that comprise a word.
Basic research findings that have been translated into an experimental therapy to improve phonetic production (TIPP) may hold promise for both types of aphasia patients. TIPP is based on findings that delineate the functional architecture of normal language and of speech deficits in aphasia, and that are designed to harness aspects of speech and language that have been shown to be spared in aphasia. These aspects include preservation of phonological/lexical functional architecture, despite deficits in speech output; and the ability to select the appropriate target word, despite making sound errors. Investigators will undertake a pilot study of TIPP training in ten patients: five with IFG lesions and five with SMG lesions.
TIPP training will be given twice per week for ten weeks and consists of two parts that differ only by whether the therapist intones the target word or uses a normal tone. The therapist uses pairs of words having a “T” and “D” sounds; the word is imbedded in the phrase “speak (word) now” at a slow pace, either intoned or at a normal tone. Then, the therapist and patient produce the phrase together followed by the patient alone producing the phrase. Patients will be tested prior to therapy (baseline), immediately after TIPP training and again after two months to assess whether progress is sustained and generalized to words with b/p and g/k sounds. If the pilot data show promise, the investigators would apply for a second phase to test three hypotheses in patients and healthy volunteers that might explain how and why TIPP therapy works to improve speech sounds.
Significance: The pilot research may ultimately lead to improved speech rehabilitation for patients who develop aphasia following stroke.
Sheila Blumstein, Ph.D.
The goal of my research over the past 40+ years has been to understand the nature of language processing deficits in aphasia and to gain insight into the neural systems underlying language with a particular focus on speech processing, the mapping of sound structure on to the lexicon, and lexical processing. I have had extraordinary mentors in my career including Roman Jakobson, Harold Goodglass, and Ken Stevens, and I have been fortunate to have received continuous NIH funding for my research since 1976. This support has allowed me to do basic research on the acoustic properties of speech and to examine the acoustic properties that give rise to the phonetic categories of speech, to identify and characterize speech production, speech perception, and lexical processing deficits in aphasia, and more recently to begin to map out the neural systems underlying speech and lexical processing in normals using functional neuroimaging. I use a broad range of methodologies in my research including psychophysical, eyetracking, naming, lexical decision, discrimination and phonetic classification tasks, and have extensive experience doing acoustic analyses of phonetic properties of speech in both normal and aphasic participants. I now would like to take my funded research in a new direction, applying the work I have done on speech and lexical processing in aphasia to aphasia therapy and recovery. I believe my lab is well-positioned to take this next step translating my basic science work to the bedside.