Harold Burton, Ph.D.
We use functional magnetic resonance imaging (fMRI) to investigate brain changes to sensory deficits in different patient groups. In adult onset sensorineural unilateral hearing loss (UHL) we found alterations in auditory cortex such that inputs to the hemisphere on the side of the intact ear increased over a normal pattern of greater crossed auditory processing. These changes possibly underlie problems that patients with UHL experience with sound localization and understanding speech in noise. A current project examines cortical activity associated with processing intelligible speech in the presence of various levels of spectral degradation. We hypothesize that those with UHL will show altered activation of the normal speech recognition brain areas when processing degraded speech. We also found adaptive changes to blindness in prior studies that involved cross-modal activation of visual cortex and altered response dynamics in several non-visual cortical areas. Illustrative were instances of using visual cortex to process tactile information generally or specifically for Braille reading. Additionally in blind, semantic language tasks, like verb generation to a presented noun, activated visual cortex as did word recognition tasks based on learning through Braille or listening. These findings show that language information obtained through touch or sound engages visual cortex in blind people.
Our studies in these patient groups indicate that brain networks change in response to altered sensations. Some adaptations may be beneficial, as in the blind. With unilateral hearing loss the cortical changes do not compensate when listening in degraded auditory conditions.
Burton, H, Snyder, AZ, and Raichle, ME (2014) Resting state functional connectivity in early blind humans. Front Sys Neurosci 8:51. DOI: 10.3389/fnsys.2014.00051
Firszt, JB, Reeder, RM, Holden, TA, Burton, H, and Chole, RS (2013) Changes resulting from hearing recovery after extended congenital unilateral hearing loss. Front Sys Neurosci 7:108. DOI: 10.3389/fnsys.2013.00108.
Burton, H, Firszt, JB, and Holden, T (2013) Hearing thresholds and fMRI of auditory cortex following eighth cranial nerve surgery. Otolaryngol Head Neck Surg 149(3):492-499. DOI: 10.1177/0194599813495179.
Roland, JL, Hacker, CD, Breshears, JD, Gaona, CM, Hogan, RE, Burton, H, Corbetta, M, and Leuthardt, EC (2013) Brain mapping in a patient with congenital blindness ─ a case for multimodal approaches Front Hum Neurosci 7:431. DOI: 10.3389/fnhum.2013.00431
Burton H., Firszt J.B., Holden T., Agato, A., and Uchanski R. (2012). Activation lateralization in human core, belt, and parabelt auditory fields with unilateral deafness and normal hearing. Brain Research, 1454:33-47 DOI: 10.1016/j.brainres.2012.02.066.
Burton H., Sinclair, R.J. and Agato A. (2012). Recognition memory for Braille or spoken words: An fMRI study in early blind. Brain Research, 1438:22-34. DOI: 10.1016/j.brainres.2011.12.032
Last Updated: 8/15/2014 9:51:13 AM