title: Asymmetry of temporal auditory T-complex: right ear-left hemisphere advantage in Tb timing in children.
abstract: OBJECTIVE
  To investigate brain asymmetry of the temporal auditory evoked potentials (T-complex) in response to monaural stimulation in children compared to adults.
  
  
  METHODS
  Ten children (7 to 9 years) and ten young adults participated in the study. All were right-handed. The auditory stimuli used were tones (1100 Hz, 70 dB SPL, 50 ms duration) delivered monaurally (right, left ear) at four different levels of stimulus onset asynchrony (700-1100-1500-3000 ms). Latency and amplitude of responses were measured at left and right temporal sites according to the ear stimulated.
  
  
  RESULTS
  Peaks of the three successive deflections (Na-Ta-Tb) of the T-complex were greater in amplitude and better defined in children than in adults. Amplitude measurements in children indicated that Na culminates on the left hemisphere whatever the ear stimulated whereas Ta and Tb culminate on the right hemisphere but for left ear stimuli only. Peak latency displayed different patterns of asymmetry. Na and Ta displayed shorter latencies for contralateral stimulation. The original finding was that Tb peak latency was the shortest at the left temporal site for right ear stimulation in children. Amplitude increased and/or peak latency decreased with increasing SOA, however no interaction effect was found with recording site or with ear stimulated.
  
  
  CONCLUSIONS
  Our main original result indicates a right ear-left hemisphere timing advantage for Tb peak in children. The Tb peak would therefore be a good candidate as an electrophysiological marker of ear advantage effects during dichotic stimulation and of functional inter-hemisphere interactions and connectivity in children.
authors.affiliation: UMR U930, INSERM, Tours, France; Université François-Rabelais de Tours, France. Electronic address: nicole.bruneau@univ-tours.fr.
authors.forename: Nicole
authors.initials: N
authors.lastname: Bruneau
authors.affiliation: INSERM, U1028, CNRS, UMR5292, Lyon Neuroscience Research Center, Brain Dynamics and Cognition Team, Lyon F-69500, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bidet-Caulet
authors.affiliation: UMR U930, INSERM, Tours, France; Université François-Rabelais de Tours, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Roux
authors.affiliation: UMR U930, INSERM, Tours, France; Université François-Rabelais de Tours, France; CHRU de Tours, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Bonnet-Brilhault
authors.affiliation: UMR U930, INSERM, Tours, France; Université François-Rabelais de Tours, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Gomot
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D002648:Child; D004423:Ear / Q000502:physiology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: Auditory; Children; Event-related potentials (ERPs); Interhemispheric asymmetry; Right ear–left hemisphere advantage; Stimulation rate; T-complex; Tones