Specialization of the specialized in features of external human brain morphology.
Level 4 - case-series / case-control
Cross-sectional comparative study
PubMed 17004946 · doi:10.1111/j.1460-9568.2006.05031.x
What was done
Multiple raters, blinded to subject identity and hemisphere, evaluated the Omega Sign (OS)—an anatomical landmark of the precentral gyrus linked to hand movement representation—using gross visual inspection. The sample comprised 64 matched brains divided into 16 expert string players, 16 expert pianists, and 32 non-musicians. Inter- and intra-observer reliability was evaluated using kappa statistics.
What was found
Intra- and interobserver reliabilities were reported as high. Musicians had a more pronounced OS expression than non-musicians, with keyboard players showing a left-hemisphere advantage and string players showing a right-hemisphere advantage. The abstract reports no numerical values, kappa coefficients, or effect sizes.
Why it matters
This study shows that gross anatomical features of the motor cortex can differentiate not only musicians from non-musicians but also sub-specialties of musicians based on instrument-specific manual dominance demands.
Limits
The cross-sectional design cannot establish whether these morphological differences are driven by training-induced neuroplasticity or innate pre-existing anatomy. The sample size is modest (16 per musician group), and the abstract omits exact statistical scores, confidence intervals, and p-values.