TY - JOUR T1 - Binaural Interactions Develop in the Auditory Brainstem of Children Who Are Deaf: Effects of Place and Level of Bilateral Electrical Stimulation JF - The Journal of Neuroscience JO - J. Neurosci. SP - 4212 LP - 4223 DO - 10.1523/JNEUROSCI.5741-11.2012 VL - 32 IS - 12 AU - Karen A. Gordon AU - Claire Salloum AU - Gurvinder S. Toor AU - Richard van Hoesel AU - Blake C. Papsin Y1 - 2012/03/21 UR - http://www.jneurosci.org/content/32/12/4212.abstract N2 - Bilateral cochlear implants (CIs) might promote development of binaural hearing required to localize sound sources and hear speech in noise for children who are deaf. These hearing skills improve in children implanted bilaterally but remain poorer than normal. We thus questioned whether the deaf and immature human auditory system is able to integrate input delivered from bilateral CIs. Using electrophysiological measures of brainstem activity that include the Binaural Difference (BD), a measure of binaural processing, we showed that a period of unilateral deprivation before bilateral CI use prolonged response latencies but that amplitudes were not significantly affected. Tonotopic organization was retained to some extent as evidenced by an elimination of the BD with large mismatches in place of stimulation between the two CIs. Smaller place mismatches did not affect BD latency or amplitude, indicating that the tonotopic organization of the auditory brainstem is underdeveloped and/or not well used by CI stimulation. Finally, BD amplitudes decreased when the intensity of bilateral stimulation became weighted to one side and this corresponded to a perceptual shift of sound away from midline toward the side of increased intensity. In summary, bilateral CI stimulation is processed by the developing human auditory brainstem leading to perceptual changes in sound location and potentially improving hearing for children who are deaf. ER -