Daniel Senkowski and Ulrich Pomper contributed equally to the article.
Beta-band activity in auditory pathways reflects speech localization and recognition in bilateral cochlear implant users
Article first published online: 7 OCT 2013
Copyright © 2013 Wiley Periodicals, Inc.
Human Brain Mapping
Volume 35, Issue 7, pages 3107–3121, July 2014
How to Cite
Senkowski, D., Pomper, U., Fitzner, I., Engel, A. K. and Kral, A. (2014), Beta-band activity in auditory pathways reflects speech localization and recognition in bilateral cochlear implant users. Hum. Brain Mapp., 35: 3107–3121. doi: 10.1002/hbm.22388
- Issue published online: 11 JUN 2014
- Article first published online: 7 OCT 2013
- Manuscript Accepted: 22 JUL 2013
- Manuscript Revised: 12 JUL 2013
- Manuscript Received: 14 MAR 2013
- EU. Grant Numbers: ERC-2010-StG_20091209, IST-2005-27268, NEST-PATH-043457, HEALTH-F2–2008-200728, ERC-2010-AdG-269716
- Young Investigator Support Grant of the University Medical Center Hamburg-Eppendorf. Grant Number: NWF-10/12
- Deutsche Forschungsgemeinschaft. Grant Number: Cluster of Excellence 1077 (Hearing4all)
- oscillatory activity;
- cortical plasticity;
- beta-band responses
In normal-hearing listeners, localization of auditory speech involves stimulus processing in the postero-dorsal pathway of the auditory system. In quiet environments, bilateral cochlear implant (CI) users show high speech recognition performance, but localization of auditory speech is poor, especially when discriminating stimuli from the same hemifield. Whether this difficulty relates to the inability of the auditory system to translate binaural electrical cues into neural signals, or to a functional reorganization of auditory cortical pathways following long periods of binaural deprivation is unknown. In this electroencephalography study, we examined the processing of auditory syllables in postlingually deaf adults with bilateral CIs and in normal-hearing adults. Participants were instructed to either recognize (“recognition” task) or localize (“localization” task) the syllables. The analysis focused on event-related potentials and oscillatory brain responses. N1 amplitudes in CI users were larger in the localization compared with recognition task, suggesting an enhanced stimulus processing effort in the localization task. Linear beamforming of oscillatory activity in CI users revealed stronger suppression of beta-band activity after 200 ms in the postero-dorsal auditory pathway for the localization compared with the recognition task. In normal-hearing adults, effects for longer latency event-related potentials were found, but no effects were observed for N1 amplitudes or beta-band responses. Our study suggests that difficulties in speech localization in bilateral CI users are not reflected in a functional reorganization of cortical auditory pathways. New signal processing strategies of cochlear devices preserving unambiguous binaural cues may improve auditory localization performance in bilateral CI users. Hum Brain Mapp 35:3107–3121, 2014. © 2013 Wiley Periodicals, Inc.