Our research program proposes to chart the unfolding of language comprehension in unimpaired adults as well as in adults with aphasia secondary to stroke. We begin with the position that sentence comprehension is rooted in cognitive and neurobiological architectures that are likely to be constrained by various real-time processing demands under 'normal'operations. In this revised proposal we focus on lexical and structural processing routines with the major comparison of interest being between regular and slowed rates of speech. We slow rate of speech input to a rate just outside the normal range of 4 to 6 syllables per second and examine how the language comprehension process is modified in neurologically intact and compromised individuals. Our purpose in doing so is to uncover properties of language comprehension that might not be apparent under normal time constraints, and to reveal the intricacies of the comprehension deficit, in particular, in Broca's aphasia. For example, we hypothesize that the functional deficit observed under normal input conditions may be reduced under slow input conditions. We combine evidence from lesion-behavior analyses, functional neuroimaging and functional connectivity to better define which regions are actively recruited during sentence processing as well as to shed light on the functional commitment of specific brain regions to aspects of sentence comprehension. We anticipate that our work will have important implications for rehabilitation efforts in aphasia.
: Aphasia, a language disorder caused by stroke, has enormous physical, emotional, and financial consequences for those individuals and families affected. It is estimated that there are approximately 1,000,000 individuals in the United States who have aphasia. This project seeks to uncover the details of the language deficit in aphasia through behavioral and brain mapping techniques, with implications for rehabilitation.
|Ferrill, Michelle; Love, Tracy; Walenski, Matthew et al. (2012) The time-course of lexical activation during sentence comprehension in people with aphasia. Am J Speech Lang Pathol 21:S179-89|
|Brumm, Kathleen P; Perthen, Joanna E; Liu, Thomas T et al. (2010) An arterial spin labeling investigation of cerebral blood flow deficits in chronic stroke survivors. Neuroimage 51:995-1005|