title: Hemispheric Asymmetry of Endogenous Neural Oscillations in Young Children: Implications for Hearing Speech In Noise.
abstract: Speech signals contain information in hierarchical time scales, ranging from short-duration (e.g., phonemes) to long-duration cues (e.g., syllables, prosody). A theoretical framework to understand how the brain processes this hierarchy suggests that hemispheric lateralization enables specialized tracking of acoustic cues at different time scales, with the left and right hemispheres sampling at short (25 ms; 40 Hz) and long (200 ms; 5 Hz) periods, respectively. In adults, both speech-evoked and endogenous cortical rhythms are asymmetrical: low-frequency rhythms predominate in right auditory cortex, and high-frequency rhythms in left auditory cortex. It is unknown, however, whether endogenous resting state oscillations are similarly lateralized in children. We investigated cortical oscillations in children (3-5 years; N = 65) at rest and tested our hypotheses that this temporal asymmetry is evident early in life and facilitates recognition of speech in noise. We found a systematic pattern of increasing leftward asymmetry for higher frequency oscillations; this pattern was more pronounced in children who better perceived words in noise. The observed connection between left-biased cortical oscillations in phoneme-relevant frequencies and speech-in-noise perception suggests hemispheric specialization of endogenous oscillatory activity may support speech processing in challenging listening environments, and that this infrastructure is present during early childhood.
authors.affiliation: Auditory Neuroscience Laboratory, Northwestern University, Evanston, Illinois 60208, USA.|Department of Communication Sciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Thompson
authors.affiliation: Auditory Neuroscience Laboratory, Northwestern University, Evanston, Illinois 60208, USA.|Department of Communication Sciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Kali
authors.initials: K
authors.lastname: Woodruff Carr
authors.affiliation: Auditory Neuroscience Laboratory, Northwestern University, Evanston, Illinois 60208, USA.|Department of Communication Sciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Travis
authors.initials: T
authors.lastname: White-Schwoch
authors.affiliation: Auditory Neuroscience Laboratory, Northwestern University, Evanston, Illinois 60208, USA.|Department of Communication Sciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Tierney
authors.affiliation: Auditory Neuroscience Laboratory, Northwestern University, Evanston, Illinois 60208, USA.|Department of Communication Sciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Trent
authors.initials: T
authors.lastname: Nicol
authors.affiliation: Auditory Neuroscience Laboratory, Northwestern University, Evanston, Illinois 60208, USA.|Department of Communication Sciences, Northwestern University, Evanston, Illinois 60208, USA.|Institute for Neuroscience, Northwestern University, Evanston, Illinois 60208, USA.|Department of Neurobiology &Physiology, Northwestern University, Evanston, Illinois 60208, USA.|Department of Otolaryngology, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Kraus
mesh_terms: D000161:Acoustic Stimulation; D001303:Auditory Cortex / Q000502:physiology*; D002675:Child, Preschool; D005072:Evoked Potentials, Auditory; D007839:Functional Laterality; D006801:Humans; D009622:Noise; D013067:Speech Perception