title: Representation of pitch chroma by multi-peak spectral tuning in human auditory cortex.
abstract: Musical notes played at octave intervals (i.e., having the same pitch chroma) are perceived as similar. This well-known perceptual phenomenon lays at the foundation of melody recognition and music perception, yet its neural underpinnings remain largely unknown to date. Using fMRI with high sensitivity and spatial resolution, we examined the contribution of multi-peak spectral tuning to the neural representation of pitch chroma in human auditory cortex in two experiments. In experiment 1, our estimation of population spectral tuning curves from the responses to natural sounds confirmed--with new data--our recent results on the existence of cortical ensemble responses finely tuned to multiple frequencies at one octave distance (Moerel et al., 2013). In experiment 2, we fitted a mathematical model consisting of a pitch chroma and height component to explain the measured fMRI responses to piano notes. This analysis revealed that the octave-tuned populations-but not other cortical populations-harbored a neural representation of musical notes according to their pitch chroma. These results indicate that responses of auditory cortical populations selectively tuned to multiple frequencies at one octave distance predict well the perceptual similarity of musical notes with the same chroma, beyond the physical (frequency) distance of notes.
authors.affiliation: Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address: mlmoerel@umn.edu.
authors.forename: Michelle
authors.initials: M
authors.lastname: Moerel
authors.affiliation: Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University, Maastricht, 6200 MD, the Netherlands; Maastricht Brain Imaging Center (MBIC), Maastricht University, Maastricht, 6229 EV, the Netherlands.
authors.forename: Federico
authors.initials: F
authors.lastname: De Martino
authors.affiliation: Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University, Maastricht, 6200 MD, the Netherlands; Maastricht Brain Imaging Center (MBIC), Maastricht University, Maastricht, 6229 EV, the Netherlands.
authors.forename: Roberta
authors.initials: R
authors.lastname: Santoro
authors.affiliation: Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Essa
authors.initials: E
authors.lastname: Yacoub
authors.affiliation: Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University, Maastricht, 6200 MD, the Netherlands; Maastricht Brain Imaging Center (MBIC), Maastricht University, Maastricht, 6229 EV, the Netherlands.
authors.forename: Elia
authors.initials: E
authors.lastname: Formisano
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009146:Music; D009415:Nerve Net / Q000502:physiology*; D010897:Pitch Discrimination / Q000502:physiology*
keywords: High field functional MRI; Human auditory cortex; Music; Octave percept; Pitch chroma; fMRI encoding