Mirror-symmetric tonotopic maps in human primary auditory cortex.
Understanding the functional organization of the human primary auditory cortex (PAC) is an essential step in elucidating the neural mechanisms underlying the perception of sound, including speech and music. Based on invasive research in animals, it is believed that neurons in human PAC that respond selectively with respect to the spectral content of a sound form one or more maps in which neighboring patches on the cortical surface respond to similar frequencies (tonotopic maps). The number and the cortical layout of such tonotopic maps in the human brain, however, remain unknown. Here we use silent, event-related functional magnetic resonance imaging at 7 Tesla and a cortex-based analysis of functional data to delineate with high spatial resolution the detailed topography of two tonotopic maps in two adjacent subdivisions of PAC. These maps share a low-frequency border, are mirror symmetric, and clearly resemble those of presumably homologous fields in the macaque monkey.
Formisano
Elia
E
Department of Cognitive Neuroscience, Faculty of Psychology, Universiteit Maastricht, Postbus 616, 6200MD Maastricht, The Netherlands.
Kim
Dae Shik
DS
Di Salle
Francesco
F
van de Moortele
Pierre Francois
PF
Ugurbil
Kamil
K
Goebel
Rainer
R
D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D014644:Genetic Variation / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male