Application of Graph Theory to Both Resting-state and Task-based fMRI Data to Uncover Brain-behavior Relationships Related to Therapy Outcomes in Aphasia

Aphasia is a loss of language due to stroke or other brain injury. Word-finding in conversation is a universal and persistent difficulty in aphasia. While several techniques exist to improve word-finding in aphasia, it is unclear how the brain changes in response to behavioral therapy. In this study, persons with aphasia will receive behavioral therapy aimed at helping them to be more successful at finding words. Twenty therapy sessions will be provided in a 10-week period. Each therapy session will last about 2 hours and will include a variety of language tasks. Prior to beginning word-finding therapy, each participant will receive two fMRI scans, spaced 10 weeks apart. After finishing therapy, each participant will receive two additional fMRI scans, spaced 10 weeks apart. For a portion of the MRI scan, participants will complete language tasks. The purpose of these fMRI scans is to measure brain changes that may occur due to successful behavioral therapy. The hypotheses are as follows: First, that the behavioral therapy will improve word-finding as it has been shown to do in the past. Second, that the brain will change in a couple of different ways. It is expected that the network of regions that support word-finding will be more connected and work together more efficiently after therapy. It is also expected that the networks of regions that support other aspects of cognitive function, such as attention and executive function, will also be more connected and work together more efficiently.