Abstract: Cross-modal reorganization refers to the functional reassignment of cortex to process inputs from an intact sensory modality when sensory input from its preferred modality is reduced or absent. This study seeks to examine cross-modal reorganization in young deaf adults who have used a hearing aid or a cochlear implant or without devices compared to young adults without hearing loss. Cortical visually evoked potentials (CVEPs) were collected in response to a visual motion stimulus. The use of CVEPs allows us to compare cross-modal reorganization between groups. Preliminary results suggest similar CVEP waveforms between young deaf individuals with and without amplification.
Summary Rationale: Cross-modal reorganization refers to the functional reassignment of cortex to process inputs from an intact sensory modality when sensory input from its preferred modality is reduced or absent. Various publications and studies have documented cross-modal plasticity in children and adults with cochlear implants and hearing aids, finding areas of auditory cortex repurposed for the representation and/or processing of visual information. However, more research is needed regarding the developmental trajectory of cross-modal reorganization, in particular at the stage of early adulthood.
Objectives: This study examines cross-modal reorganization in young deaf adults who have used a hearing device (hearing aids and/or cochlear implants) compared to those who do not utilize amplification. The dataset used for this analysis is part of a larger project: Neurocognitive Plasticity in Young Deaf Adults: Effects of Cochlear Implantation and Sign Language Exposure NIH RO1 DC016346 (MPIs: Matthew Dye and Anu Sharma). Our aim for this poster is to examine cortical cross-modal reorganization of vision as a function of hearing loss and device use.
Design: Participants include 26 college students recruited at the National Technical College for the Deaf within the Rochester Institute of Technology (RIT). Of these, 10 participants used devices and 16 did not use hearing devices. Of those who had hearing devices, 8 used hearing aids and 2 used cochlear implants. Twenty-one college students with typical hearing were recruited at the University of Colorado Boulder as age-matched controls. To measure cortical responses, a 128-channel high-density EEG system was used to obtain cortical visually evoked potentials (CVEPs) in response to a visual motion stimulus. Cortical responses were averaged and examined across the following regions of interest: the right temporal cortex, left temporal cortex, occipital cortex, and frontal cortex.
Results: Preliminary results suggest that there is no difference in CVEP latencies, absolute amplitude, or peak-to-peak amplitudes for the P1, N1, and P2 components in the examined regions of interest for those with no devices compared to those with devices. This suggests that there are no differences in cross-modal reorganization between these two groups.
Conclusions: In this preliminary dataset, we see no difference in CVEP morphology, latency, and amplitudes between young deaf adults who have worn hearing aids and cochlear implants compared to those who have not. If CVEPs are considered markers of cross-modal plasticity, then these preliminary results may suggest that cross-modal reorganization may occur in these populations to a similar extent. Our results may have implications for better understanding the role of auditory input to the cortex in cross-modal reorganization.
Learning Objectives:
Upon completion, participants will be able to define cross-modal plasticity.
Upon completion, participants will be able to identify the sensory period for cortical auditory maturation.
Upon completion, participants will be able to describe cross-modal reorganization from vision in young adults who were implanted early or later in childhood.
.png)
