Brain Responses to Musical Feature Changes in Adolescent Cochlear Implant Users

Abstract

Cochlear implants (CIs) are primarily designed to assist deaf individuals in perception of speech, although possibilities for music fruition have also been documented. Previous studies have indicated the existence of neural correlates of residual music skills in postlingually deaf adults and children. However, little is known about the behavioral and neural correlates of music perception in the new generation of prelingually deaf adolescents who grew up with CIs. With electroencephalography (EEG), we recorded the mismatch negativity (MMN) of the auditory event-related potential to changes in musical features in adolescent CI users and in normal-hearing (NH) age mates. EEG recordings and behavioral testing were carried out before (T1) and after (T2) a 2-week music training program for the CI users and in two sessions equally separated in time for NH controls. We found significant MMNs in adolescent CI users for deviations in timbre, intensity, and rhythm, indicating residual neural prerequisites for musical feature processing. By contrast, only one of the two pitch deviants elicited an MMN in CI users. This pitch discrimination deficit was supported by behavioral measures, in which CI users scored significantly below the NH level. Overall, MMN amplitudes were significantly smaller in CI users than in NH controls, suggesting poorer music discrimination ability. Despite compliance from the CI participants, we found no effect of the music training, likely resulting from the brevity of the program. This is the first study showing significant brain responses to musical feature changes in prelingually deaf adolescent CI users and their associations with behavioral measures, implying neural predispositions for at least some aspects of music processing. Future studies should test any beneficial effects of a longer lasting music intervention in adolescent CI users.

Music-based training for pediatric CI recipients: A systematic analysis of published studies

“…Across studies, participants ranged in age from 4 to 18 years of age. Within some individual studies [16, 21, 22], the age range for participants encompassed three different stages of Piagetian development. As is the case with speech and language, music perception and performance are influenced by cognitive, behavioral, and social maturation.…”

“…As is the case with speech and language, music perception and performance are influenced by cognitive, behavioral, and social maturation. Consequently, chronological and hearing age at the time of the study can influence successful engagement in music training and outcomes [3, 21]. …”

“…Table 2 indicates which studies reported age at testing [17, 18] and implantation [17, 18, 23] or duration of CI use [21]; which variables were integrated into analyses; and whether these factors had significant impact. Some studies [19, 21] enrolled children within a relatively narrow age range, which is likely to result in less maturational variability across participants.…”

The Effects of Musical Experience and Hearing Loss on Solving an Audio-Based Gaming Task

“…Effects of the training were found in linguistic identification tests after controlled training of combining the acoustic information of a hearing aid with the electric information from a cochlear implant [47]. Some of these results are related to brain development [1,46].…”

“…Various experiments have investigated possible long-term effects of informal music activities provided to participants at schools [1], and measured the effectiveness of long-term music lessons for improving the perception of environmental sounds [45]. In short-term training for cochlear implant users, little progress was found in terms of music skills [46]. Effects of the training were found in linguistic identification tests after controlled training of combining the acoustic information of a hearing aid with the electric information from a cochlear implant [47].…”