Using magnetoencephalography (MEG), we compared the processing of sinusoidal tones in the auditory cortex of 12 non-musicians, 12 professional musicians and 13 amateur musicians. We found neurophysiological and anatomical differences between groups. In professional musicians as compared to non-musicians, the activity evoked in primary auditory cortex 19-30 ms after stimulus onset was 102% larger, and the gray matter volume of the anteromedial portion of Heschl's gyrus was 130% larger. Both quantities were highly correlated with musical aptitude, as measured by psychometric evaluation. These results indicate that both the morphology and neurophysiology of Heschl's gyrus have an essential impact on musical aptitude.

IntroductionIn a series of earlier papers, ([ST1-4]) we began a systematic study of locally analytic representations of a locally L-analytic group G, where L ⊆ C p is a finite extension of Q p . Such a representation is given by a continuous action of G on a locally convex topological vector space V over a spherically complete extension field K ⊆ C p of L, such that the orbit maps g → gv are locally analytic functions on G. When G is the group of L-points of an algebraic group, the class of such representations includes many interesting examples, such as the principal series representations studied in [ST2], the finite dimensional algebraic representations, and the smooth representations of Langlands theory. A reasonable theory of such representations requires the identification of a finiteness condition that is broad enough to include the important examples and yet restrictive enough to rule out pathologies. In this paper we present such a finiteness condition that we call "admissibility" for locally analytic representations (provided the field K is discretely valued). The admissible locally analytic representations, among which are the examples mentioned above, form an abelian category.Our approach to the characterization of admissible representations is based on the algebraic approach to such representations begun in [ST2]. As in that paper, we require that the vector space V carrying the locally analytic representation be of compact type, a topological condition whose most important consequence is that V is reflexive. We focus our attention on the algebra D(G, K) of locally analytic distributions on G. This algebra is the continuous dual of the locally analytic, K-valued functions on G, with multiplication given by convolution. When G is compact, D(G, K) is a Fréchet algebra, but in general is neither noetherian nor commutative. If V is a locally analytic G-representation, then its continuous dual V ′ b , with its strong topology, becomes a module over D(G, K). We identify a subcategory of the module category of D(G, K) that we call the coadmissible modules. We show that any coadmissible module carries a canonical Fréchet topology. We say that V is admissible if V ′ b is topologically isomorphic to a coadmissible module. If G is not compact, we say that V is admissible if it is admissible as a representation for one (or equivalently any) compact open subgroup of G.

The relative pitch of harmonic complex sounds, such as instrumental sounds, may be perceived by decoding either the fundamental pitch (f0) or the spectral pitch (fSP) of the stimuli. We classified a large cohort of 420 subjects including symphony orchestra musicians to be either f0 or fSP listeners, depending on the dominant perceptual mode. In a subgroup of 87 subjects, MRI (magnetic resonance imaging) and magnetoencephalography studies demonstrated a strong neural basis for both types of pitch perception irrespective of musical aptitude. Compared with f0 listeners, fSP listeners possessed a pronounced rightward, rather than leftward, asymmetry of gray matter volume and P50m activity within the pitch-sensitive lateral Heschl's gyrus. Our data link relative hemispheric lateralization with perceptual stimulus properties, whereas the absolute size of the Heschl's gyrus depends on musical aptitude.

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Playing a musical instrument is associated with numerous neural processes that continuously modify the human brain and may facilitate characteristic auditory skills. In a longitudinal study, we investigated the auditory and neural plasticity of musical learning in 111 young children (aged 7-9 y) as a function of the intensity of instrumental practice and musical aptitude. Because of the frequent co-occurrence of central auditory processing disorders and attentional deficits, we also tested 21 children with attention deficit (

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Absolute pitch (AP) perception is the auditory ability to effortlessly recognize the pitch of any given tone without external reference. To study the neural substrates of this rare phenomenon, we developed a novel behavioral test, which excludes memory-based interval recognition and permits quantification of AP proficiency independently of relative pitch cues. AP- and non-AP-possessing musicians were studied with morphological and functional magnetic resonance imaging (fMRI) and magnetoencephalography. Gray matter volume of the right Heschl's gyrus (HG) was highly correlated with AP proficiency. Right-hemispheric auditory evoked fields were increased in the AP group. fMRI revealed an AP-dependent network of right planum temporale, secondary somatosensory, and premotor cortices, as well as left-hemispheric "Broca's" area. We propose the right HG as an anatomical marker of AP and suggest that a right-hemispheric network mediates AP "perception," whereas pitch "labeling" takes place in the left hemisphere.