title: Gamma band pitch responses in human auditory cortex measured with magnetoencephalography.
abstract: We have previously used direct electrode recordings in two human subjects to identify neural correlates of the perception of pitch (Griffiths, Kumar, Sedley et al., Direct recordings of pitch responses from human auditory cortex, Curr. Biol. 22 (2010), pp. 1128-1132). The present study was carried out to assess virtual-electrode measures of pitch perception based on non-invasive magnetoencephalography (MEG). We recorded pitch responses in 13 healthy volunteers using a passive listening paradigm and the same pitch-evoking stimuli (regular interval noise; RIN) as in the previous study. Source activity was reconstructed using a beamformer approach, which was used to place virtual electrodes in auditory cortex. Time-frequency decomposition of these data revealed oscillatory responses to pitch in the gamma frequency band to occur, in Heschl's gyrus, from 60 Hz upwards. Direct comparison of these pitch responses to the previous depth electrode recordings shows a striking congruence in terms of spectrotemporal profile and anatomical distribution. These findings provide further support that auditory high gamma oscillations occur in association with RIN pitch stimuli, and validate the use of MEG to assess neural correlates of normal and abnormal pitch perception.
authors.affiliation: Auditory Group, Institute of Neuroscience, Newcastle University Medical School, Newcastle Upon Tyne, Tyne and Wear, NE2 4HH UK. willsedley@gmail.com
authors.forename: William
authors.initials: W
authors.lastname: Sedley
authors.forename: Sundeep
authors.initials: S
authors.lastname: Teki
authors.forename: Sukhbinder
authors.initials: S
authors.lastname: Kumar
authors.forename: Tobias
authors.initials: T
authors.lastname: Overath
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Barnes
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Griffiths
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology*; D055815:Young Adult