Neurocognitive Plasticity in Young Deaf Adults – Effects of Cochlear Implantation and Sign Language Exposure
- We are excited to announce a collaboration with Matt Dye, Ph.D. at the Rochester Institute of Technology/National Technical Institute for the Deaf (RIT/NTID), where we will be working on one of the first NIH-funded, large-scale studies to examine spoken language outcomes in the first generation of cochlear implant users who were implanted in childhood and are now young adults. This project aims to characterize the impact of cochlear implantation on cognitive function (sequence processing, executive function), language outcomes, central auditory development and cross-modal plasticity in this population. Given the unique sample of young deaf adults at RIT/NTID, this project will also allow us to examine the effects of early exposure to American Sign language (ASL) and other communication modes on sequence processing, executive control, and spoken language outcomes.
Hearing Aid Plasticity Intervention (HAPI) Project
- We are currently enrolling adults with normal hearing and adults with suspected age-related hearing loss to participate in an exciting new study funded by the Hearing Industry Research Consortium. The HAPI Project aims to examine the effects of well-fit amplification with hearing aids on cross-modal re-organization, cognitive function, and audio-visual integration in adults with early-stage, age-related hearing loss. Hearing loss adults will receive free, state-of-the art hearing aids for up to a year fit by an experience, licensed audiologist. Given a growing body of research linking untreated hearing loss to cognitive decline, including all-cause dementia, this research has the potential for immense impact.
Effectiveness of Therapy Via Telemedicine Following Cochlear Implants (TACIT)
- The goal of this NIH-funded study is to compare and contrast the ways in which children with unilateral or bilateral cochlear implants or hearing aids benefit from therapy when the treatment is provided via telemedicine technology and in person. While most speech therapies have typically been delivered in person, many patients live in rural areas and do not have access to therapy services. Therapy over the internet is also becoming more and more common in the field of medicine. In this study, we are using both behavioral and neurophysiologic outcome measures at various time points to investigate the development of speech, listening, and language, as well as the development of the auditory cortex in children receiving in-person vs. telehealth therapy services.
Cortical Neuroplasticity in Single-Sided Deafness (SSD)
- The extent to which sensory pathways reorganize in single-sided deafness (SSD) is not well understood. While cochlear implantation has proved beneficial in patients with bilateral severe-profound hearing loss, there is currently little evidence demonstrating the efficacy of cochlear implantation in adults or children with SSD. The purpose of this study is to examine changes in cortical neuroplasticity in adults and children with SSD before and after cochlear implantation. High-density 128-channel electroencephalography (EEG) is used collect cortical auditory, visual, and somatosensory evoked potentials (CAEP, CVEP, CSSEP) in adults and children with SSD and a sub-population of these participants after cochlear implantation. Behavioral correlates of auditory-visual speech perception and cognition are also measured. With further research, it is possible that neurophysiological biomarkers may help predict clinical outcomes SSD patients who receive audiological intervention or may help guide the rehabilitation process for these patients.
Neurodevelopment and Reading Ability in Hearing Loss
- Hearing loss in childhood can have a profound impact on speech and language development, and may affect other areas of academic achievement such as reading. The goal of this study is to examine the neurodevelopmental processes underlying reading ability using event related potentials (ERPs) (N170, N400, P600) in normal hearing children and children with hearing loss. We have partnered with Dr. Al Kim at CU and Dr. Francesco Pavani and his team at the University of Trento, Francesco in Italy to examine how differences in phonological transparency and morphology differences in English vs. Italian affects reading development. In addition, we are examining the brain-behavior relationship underlying reading deficits in children with hearing loss. Results from this study may help develop targeted interventions to improve reading outcomes in hearing impaired children.
Functional Correlations Between Auditory-Visual Integration and Visual Cross-Modal Plasticity in Hearing Loss
- There is a lack of clinically standardized tests to assess multi-modal, auditory-visual speech perception in clinical populations with hearing loss patients with hearing loss in naturalistic listening situations (e.g. background noise), despite compelling evidence of changes in cortical resource allocation including cross-modal cortical re-organization by vision in hearing loss. In addition, auditory rehabilitation training programs that cross-modally train both the auditory and visual systems to improve speech perception performance are critically lacking for this population. To this end, we have partnered with Dr. Michael Dorman’s Cochlear Implant Laboratory at Arizona State University, where they have developed an auditory-visual speech-in-noise measurement called the AzAv Sentences. In our laboratory, we use this test to assess auditory-visual integration and its correlation with visual cross-modal plasticity in clinical populations with hearing loss. In the future, the AzAv test may provide a clinical measure to assess auditory-visual speech perception, and may prove useful in predicting outcomes and guiding rehabilitation for clinical populations with hearing loss
Cortical Neuroplasticity in Long-term Hearing Aid Use
- The extent to which sensory pathways re-organized in long-term hearing aid users may help explain some of the variability in behavioral outcomes after amplification use in adults with hearing loss. In this study, we utilize high-density EEG to examine cortical auditory, visual, and somatosensory neuroplasticity in long-term hearing aid users and the relationship between cortical function and auditory-visual speech perception, cognitive function, and social-emotional status in long-term hearing aid users.
Visual Cross-Modal Neuroplasticity and Behavioral Outcomes in Amplification Use in Age-Related Hearing Loss
- Previous studies suggest that the auditory cortex may be recruited for visual processing in deafness and in lesser degrees of hearing loss, evidence of cortical cross-modal re-organization by vision. However, it is unknown to what extent cross-modal re-organization by vision is related to functional dependence on visual cues for speech perception in the early stages of adult-onset hearing loss. Further, it remains unknown to what extent amplification use in early-stage hearing loss may reverse visual cross-modal re-organization. The short-term goal of this study is to examine the relationship between cross-modal re-organization in mild-moderate hearing loss and speech perception, and whether these changes are reversed with amplification. The long-term goal of this study is to better understand the neural mechanisms contributing to variable outcomes following audiological intervention in adults with hearing loss, as well the impact of auditory deprivation-induced cortical brain changes within the context of healthy aging. High-density EEG and behavioral techniques are used to examine visual cross-modal plasticity, auditory- and auditory-visual speech perception in background noise, and global cognitive status in normal hearing adults and adults with bilateral mild-moderate sensorineural hearing loss before and after intervention with hearing aids. Results of this study may contribute to innovation in early screening, intervention and rehabilitation for aging adults with hearing loss, and may lead to the identification of clinical biomarkers of auditory deprivation and objective benefit from amplification.
Central Auditory Development in Special Pediatric Populations with Hearing Loss: Children with Hearing Aids and Cochlear Implants, ANSD, Cochlear Nerve Deficiency, and Multiple Disabilities
- The developing auditory cortex demonstrates a high level of neuroplasticity. As such, the auditory cortex is both primed to mature normally and at risk for re-organizing abnormally, depending upon numerous factors such as whether adequate auditory stimulation is provided to the auditory cortex and whether there is appropriate timing of this stimulation. We are continuing to investigate the use of non-invasive cortical auditory evoked potentials (CAEPs), particularly the P1 CAEP biomarker, in evaluating the developmental maturation of the central auditory pathways in special pediatric populations with hearing loss, including children with hearing aids and cochlear implants, children with auditory neuropathy spectrum disorder (ANSD), children with cochlear nerve deficiency, and children with multiple disabilities. From a clinical perspective, research in this area may lead to the development of more targeted and effective rehabilitation programs children with hearing impairment who receive audiological intervention, and the P1 CAEP biomarker may prove useful in providing objective measures of benefit after audiological intervention.