Background: Simultaneous bilateral cochlear implantation promotes symmetric development of bilateral auditory pathways but binaural hearing remains abnormal. To evaluate whether bilateral cortical processing remains impaired in such children, cortical activity to unilateral and bilateral stimuli was assessed in a unique cohort of 16 children who received bilateralcochlear implants (CIs) simultaneously at 1.970.86 years of age and had similar to 4years of CI experience, providing the first opportunity to assess electrically driven cortical development in the absence of reorganized asymmetries from sequential implantation. Methods: Cortical activity to unilateral and bilateral stimuli was measured using multichannel electro-encephalography. Cortical processing in children with bilateral CIs was compared with click-elicited activity in 13 normal hearing children matched for time-in-sound. Source activity was localized using the Time Restricted, Artefact and Coherence source Suppression (TRACS) beamformer method. Results: Consistent with dominant crossed auditory pathways, normal P1 activity (similar to 100ms) was weaker to ipsilateral stimuli relative to contralateral and bilateral stimuli and both auditory cortices preferentially responded to the contralateral ear. Right hemisphere dominance was evident overall. Children with bilateral CIs maintained the expected right dominance but differences from normal included: (i) minimal changes between ipsilateral, contralateral and bilateral stimuli, (ii) weaker than normal contralateral stimulus preference, (iii) symmetric activity to bilateral stimuli, and (iv) increased occipital lobe recruitment during bilateral relative to unilateral stimulation. Between-group contrasts demonstrated lower than normal activity in the inferior parieto-occipital lobe (suggesting deficits in sensory integration) and greater than normal left frontal lobe activity (suggesting increased attention), even during passive listening. Conclusions: Together, findings suggest that early simultaneous bilateral cochlear implantation promotes normal-like auditory symmetry but that abnormalities in cortical processing consequent to deafness and/or electrical stimulation through two independent speech processors persist.
机构:
Baycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
Univ Toronto, Toronto, ON, CanadaBaycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
Alain, Claude
;
He, Yu
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Baycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, CanadaBaycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
He, Yu
;
Grady, Cheryl
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机构:
Baycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
Univ Toronto, Toronto, ON, CanadaBaycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
机构:
Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Ceponiene, R.
;
Torki, M.
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Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Torki, M.
;
Alku, P.
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Aalto Univ, FIN-02150 Espoo, FinlandUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Alku, P.
;
Koyama, A.
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Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Koyama, A.
;
Townsend, J.
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机构:
Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Univ Calif San Diego, Dept Neurosci, San Diego, CA 92103 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
机构:
Univ Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USAUniv Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USA
Dalal, Sarang S.
;
Sekihara, Kensuke
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机构:Univ Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USA
Sekihara, Kensuke
;
Nagarajan, Srikantan S.
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机构:Univ Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USA
机构:
Baycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
Univ Toronto, Toronto, ON, CanadaBaycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
Alain, Claude
;
He, Yu
论文数: 0引用数: 0
h-index: 0
机构:
Baycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, CanadaBaycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
He, Yu
;
Grady, Cheryl
论文数: 0引用数: 0
h-index: 0
机构:
Baycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
Univ Toronto, Toronto, ON, CanadaBaycrest Ctr Geriatr Care, Rotman Res Inst, Toronto, ON M6A 2E1, Canada
机构:
Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Ceponiene, R.
;
Torki, M.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Torki, M.
;
Alku, P.
论文数: 0引用数: 0
h-index: 0
机构:
Aalto Univ, FIN-02150 Espoo, FinlandUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Alku, P.
;
Koyama, A.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Koyama, A.
;
Townsend, J.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
Univ Calif San Diego, Dept Neurosci, San Diego, CA 92103 USAUniv Calif San Diego, Ctr Res Language, Project Neural & Cognit Dev, La Jolla, CA 92093 USA
机构:
Univ Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USAUniv Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USA
Dalal, Sarang S.
;
Sekihara, Kensuke
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USA
Sekihara, Kensuke
;
Nagarajan, Srikantan S.
论文数: 0引用数: 0
h-index: 0
机构:Univ Calif San Francisco, Joint Grad Grp Bioengn, San Francisco, CA 94143 USA