Project Descriptions
Sentence processing and production
This work examines normal and disordered processing and production of (primarily) complex sentences, using a variety of techniques, including eye-tracking while listening and speeded sentence verification. Of particular interest is the speed and accuracy with which normal and aphasic individuals resolve filler-gap (movement) dependencies, and referential pronouns. Work in progress examines processing of different classes of movement dependencies.
We also study recovery of language in (primarily) agrammatic aphasia. Findings have shown that recovery follows a “path of linguistic knowledge”: (a) sentences with shared linguistic properties recover together, and (b) training more complex structures (using Treatment of Underlying Forms (TUF)) results in recovery of less complex, linguistically related, structures (the Complexity Account of Treatment Efficacy (CATE) (Thompson et al., 2003). Work in progress is concerned with the neurobiology of improved language using this approach. This work is supported by the NIH: 4 R01 DC01948-01-19.
Sentactics® is a recently developed computer-automated version of TUF. Click for sample Sentactics Beta version, developed in collaboration with Dr. Ron Cole at The Center for Spoken Language Research (CSLR) at the University of Colorado. Studies examining its effects are underway. This work is supported by the NIH SBIR: R43-DC009926-01.
Verb processing and production
In this work we investigate the effects of form class (i.e., noun vs. verb) on single word comprehension and production in individuals with aphasia, primary progressive aphasia (PPA), and other neurological impairments. In addition, production of various verb types (based on argument structure properties) is examined in both single word and sentence production, using both off-line and on-line (eye tracking) tasks. Results have shown not only that nouns and verbs may be selectively impaired in aphasic people, but also that selective impairments across types of verbs is common. Verbs with a greater complexity in terms of both number and type of participant roles are more difficult to produce - both in single word and sentence production tasks - than verbs with less complex argument structure. Treatment studies examining the functional relation between verbs across types and the neural mechanism of verb and verb argument structure are presently being conducted. This work is supported by the NIH: 4 R01 DC01948-01-19.
fMRI investigations of language processing
This work uses functional magnetic resonance imaging (fMRI) to examine the brain mechanism involved in aspects of word and sentence processing in healthy young and older volunteers and to examine the neurobiology of language recovery in aphasia. This work is supported by the NIH (R01-DC007213-01-05) and formerly by the McDonnell-Pew Foundation Program in Cognitive Neuroscience and is conducted in collaboration with the Cognitive Brain Mapping Group at Northwestern University.
Studies of functional categories
Deficits in production of functional categories (grammatical morphology) are common in Broca’s aphasia with agrammatism. Studies in this area examine production, comprehension, and grammaticality judgment of functional categories and use neuroimaging (fMRI) to study the neural correlates of grammatical morpheme production and recovery in aphasia
Primary progressive aphasia
This work examines the decline of lexical and morphosyntactic aspects of production in individuals with Primary Progressive Aphasia (PPA). Studies are conducted in collaboration with Drs. M-Marsel Mesulam, Ken Paller, and Sandy Weintraub and supported by the NIH (RO1-DC008551-05)
