Representations of Spectral Differences Between Vowels in Tonotopic Regions of Auditory Cortex
AuthorFisher, Julia Marie
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractThis work examines the link between low-level cortical acoustic processing and higher-level cortical phonemic processing. Specifically, using functional magnetic resonance imaging, it looks at 1) whether or not the vowels [ɑ] and [i] are distinguishable in regions of interest defined by the first two resonant frequencies (formants) of those vowels and 2) whether or not that neural discrimination ability changes based on anatomical region. The formant-frequency based regions of interest are found to respond differentially to [ɑ] and [i] with the response to [ɑ] statistically significantly greater than the response to [i] in the averaged [ɑ] formant-frequency based region. Unexpectedly, the response to [i] is numerically but not statistically significantly greater than the response to [ɑ] in the averaged [i] formant-frequency based region. Additionally, there is not a significant interaction of this pattern with anatomical region, although early cortical auditory regions appear to show the pattern while later ones do not. Further investigation into the results leads to the hypotheses that they could be due to task-specific neural processing strategies and that the link between lower and higher-level cortical auditory processing is more complex than originally hypothesized.
Degree ProgramGraduate College