Ongoing Studies

CI speech-recognition outcomes are influenced by various combinations of top-down and bottom-up factors. As such, there is substantial individual variability in CI outcomes. Assessment tools that go beyond traditional speech-recognition measures are required in order to characterize individual differences in the relative impact of top-down vs bottom-up influences on CI outcomes. Our projects combine behavioral measures of speech recognition and cognition with concurrent neuroimaging to investigate individual variability in speech processing. 

Currently, it is unclear how individual differences within the cortical auditory system, specifically in speech-evoked brain activity, contribute to individual variability in CI speech-recognition outcomes. One reason for this gap in knowledge is that the electromagnetic signals emitted from a CI can disrupt traditional neuroimaging methods. A new optical neuroimaging tool, functional near-infrared spectroscopy (fNIRS), offers a CI-compatible imaging option that is non-invasive and unaffected by electromagnetic artifact. The knowledge gained from recent fNIRS investigations has not yet translated into clinical practice because results are often only reported at the group level; the reliability of fNIRS measurements remains somewhat poor on the single-subject level. Our research addresses this issue of reliability by controlling for the interference from systemic physiological signals in single-subject fNIRS recordings.