Interhemispheric auditory connectivity requires normal access to sound in both ears during development

Publication date: Available online 10 December 2019Source: NeuroImageAuthor(s): Daniel Smieja, Benjamin T. Dunkley, Blake C. Papsin, Vijayalakshmi Easwar, Hiroshi Yamazaki, Michael Deighton, Karen A. GordonAbstractDespite early bilateral cochlear implantation, children with congenital deafness do not develop accurate spatial hearing; we thus asked whether auditory brain networks are disrupted in these children. EEG responses were evoked unilaterally and bilaterally in 13 children with normal hearing and 16 children receiving bilateral cochlear implants simultaneously. Active cortical areas were estimated by the Time Restricted Artifact and Coherent source Suppression (TRACS) beamformer and connected cortical areas were identified by measuring coherence between source responses. A whole-brain analysis of theta band coherence revealed the strongest connections between the temporal areas in all conditions at early latencies. Stronger imaginary coherence in activity between the two auditory cortices to bilateral than unilateral input was found in children with normal hearing reflecting facilitation in the auditory network during bilateral hearing. The opposite effect, depressed coherence, was found during bilateral stimulation in children using cochlear implants. Children with cochlear implants also showed a unique auditory network in response to bilateral stimulation which was marked by increased connectivity between occipital and frontal areas. These findings suggest that corti...
Source: NeuroImage - Category: Neuroscience Source Type: research