title: Intracranial evidence for differential encoding of frequency and duration discrimination responses.
abstract: OBJECTIVE
  To identify cortical areas involved in auditory detection and discrimination of frequency and duration stimuli in an awake child.
  
  
  METHODS
  Single case study recording intracranial auditory event-related potentials to auditory odd-ball stimuli varying in duration and/or frequency.
  
  
  RESULTS
  N1 wave to detection was recorded maximally just above the Sylvian fissure 1 cm posterior to the mismatch negativity (MMN) response to discrimination. Frequency MMN overlapped with the N1 whereas duration MMN appeared 100 msec later. MMN to both duration and frequency appeared as an additive bifid response.
  
  
  CONCLUSIONS
  It is suggested that feature-specific neuronal networks are activated after changes in sounds, which may underpin a fast parallel preattentive process (MMN).
authors.affiliation: Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Trust London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Liasis
authors.forename: A
authors.initials: A
authors.lastname: Towell
authors.forename: S
authors.initials: S
authors.lastname: Boyd
mesh_terms: D000293:Adolescent; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000473:pathology*; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis; D005072:Evoked Potentials, Auditory / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D009415:Nerve Net / Q000502:physiology*