Sara Momtaz1, Deborah Moncrieff2, Gavin M Bidelman3. 1. School of Communication Sciences & Disorders, University of Memphis, Memphis, TN, USA. Electronic address: smbkhrei@memphis.edu. 2. School of Communication Sciences & Disorders, University of Memphis, Memphis, TN, USA. 3. School of Communication Sciences & Disorders, University of Memphis, Memphis, TN, USA; Institute for Intelligent Systems, University of Memphis, Memphis, TN, USA; University of Tennessee Health Sciences Center, Department of Anatomy and Neurobiology, Memphis, TN, USA.
Abstract
OBJECTIVE: Children diagnosed with auditory processing disorder (APD) show deficits in processing complex sounds that are associated with difficulties in higher-order language, learning, cognitive, and communicative functions. Amblyaudia (AMB) is a subcategory of APD characterized by abnormally large ear asymmetries in dichotic listening tasks. METHODS: Here, we examined frequency-specific neural oscillations and functional connectivity via high-density electroencephalography (EEG) in children with and without AMB during passive listening of nonspeech stimuli. RESULTS: Time-frequency maps of these "brain rhythms" revealed stronger phase-locked beta-gamma (~35 Hz) oscillations in AMB participants within bilateral auditory cortex for sounds presented to the right ear, suggesting a hypersynchronization and imbalance of auditory neural activity. Brain-behavior correlations revealed neural asymmetries in cortical responses predicted the larger than normal right-ear advantage seen in participants with AMB. Additionally, we found weaker functional connectivity in the AMB group from right to left auditory cortex, despite their stronger neural responses overall. CONCLUSION: Our results reveal abnormally large auditory sensory encoding and an imbalance in communication between cerebral hemispheres (ipsi- to -contralateral signaling) in AMB. SIGNIFICANCE: These neurophysiological changes might lead to the functionally poorer behavioral capacity to integrate information between the two ears in children with AMB. Published by Elsevier B.V.
OBJECTIVE: Children diagnosed with auditory processing disorder (APD) show deficits in processing complex sounds that are associated with difficulties in higher-order language, learning, cognitive, and communicative functions. Amblyaudia (AMB) is a subcategory of APD characterized by abnormally large ear asymmetries in dichotic listening tasks. METHODS: Here, we examined frequency-specific neural oscillations and functional connectivity via high-density electroencephalography (EEG) in children with and without AMB during passive listening of nonspeech stimuli. RESULTS: Time-frequency maps of these "brain rhythms" revealed stronger phase-locked beta-gamma (~35 Hz) oscillations in AMB participants within bilateral auditory cortex for sounds presented to the right ear, suggesting a hypersynchronization and imbalance of auditory neural activity. Brain-behavior correlations revealed neural asymmetries in cortical responses predicted the larger than normal right-ear advantage seen in participants with AMB. Additionally, we found weaker functional connectivity in the AMB group from right to left auditory cortex, despite their stronger neural responses overall. CONCLUSION: Our results reveal abnormally large auditory sensory encoding and an imbalance in communication between cerebral hemispheres (ipsi- to -contralateral signaling) in AMB. SIGNIFICANCE: These neurophysiological changes might lead to the functionally poorer behavioral capacity to integrate information between the two ears in children with AMB. Published by Elsevier B.V.
Authors: William Sedley; Phillip E Gander; Sukhbinder Kumar; Christopher K Kovach; Hiroyuki Oya; Hiroto Kawasaki; Matthew A Howard; Timothy D Griffiths Journal: Elife Date: 2016-03-07 Impact factor: 8.140