Brain Structures Differ between Musicians and Non-Musicians

Christian Gaser and Gottfried Schlaug

Su Kyung (Irene) Kim

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Introduction• Musicians -> Complex motor, auditory, somatosensory

skills • Skill acquisition -> functional enlargement of the

representative area that underlies that particular skill• Whole brain space for structural differences b/w

musicians and non-musicians• Unclear: continued practice or repetition of skills over a

long period of time -> structural changes/regional enlargement?

• Strong association b/w structural differences, musician status, and practice intensity

• Structural adaptations in response to long-term skill acquisition and the repetitive rehearsal of those skills

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Terms/definitions• Voxel: a volume element, representing a value on

a regular grid in 3D space

• VBM: Voxel-Based Morphometry -analysis of differences in local gray and white matter volume

across the whole brain

• Morphometrics: field concerned with studying variation and change in the form of organisms or objects; detecting changes in the shape of organisms

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Materials & MethodsSubjects:

• 20 male professional musicians (performing artists, full-time music teachers, full-time

conservatory students) =high-practicing group

• 20 male amateur musicians (play musical instrument regularly but profession outside

the field of music) =low-practicing group

• 40 male non-musicians (never played a musical instrument)

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Materials & Methods• 18 - 40 years

• Right-handed males

• ALL Keyboard players & formal training

• Verbal Intelligence Quotient (IQ) – Shipley Hartford Vocabulary and Abstraction test

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Materials & MethodsData acquisition and analysis :

• High-resolution anatomical images (voxel size, 1mm³) of the whole brain – 1.5T Siemens Vision whole-body scanner

• Image analysis -> VBM, a fully automatic technique for computational analysis of differences in local gray matter volume

• Voxel-by-voxel t tests / general linear model7

Results• Significant (+) correlation: musician status ↔ increase in gray matter volume

Musician status Gray matter volume

Professional Highest

Amateur Intermediate

None Lowest

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Relative differences in gray matter volume

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• Perirolandic regions: -1⁰ motor, somatosensory areas -premotor areas -anterior superior parietal areas -inferior temporal gyrus (bilaterally)• Additional (+) correlation in: -left cerebellum -left Heschl’s gyrus -left inferior frontal gyrus

• No significant effects in Planum Temporale (PT) =>Absolute Pitch (AP)

• No significant correlations b/w white matter volume & musician status

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Discussion• Premotor & cerebellar cortex (motor) -planning, preparation, execution, and control -cerebellum: cognitive skill learning & music processing

• Left Heschl’s gyrus (auditory) -neurophysiological source activity differences -listening to tones

• Superior parietal region/lobe (visual-spatial) -1) integrate multimodal sensory info -2) provide guidance for motor operations -sight-reading

• Inferior temporal gyrus (visual) -ventral visual stream 12

Discussion• Lack of a finding in white matter -1) plastic changes occur in the cerebral gray matter -2) VBM method insensitive to white matter differences -Diffusion Tensor Imaging (DTI)

• One gender -1) gender interaction -2) huge gender effects; histological differences -3) microstructural changes ↔ menstrual cycle

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Discussion• Monotonic relationship b/w musician status

and gray matter volume• Strong links b/w specialized skills & particular

brain structures

• Anatomical variability -> extraordinary abilities & self-selection for musicianship

VS.

• Adaptations to long-term musical training -> volumetric structural differences 14

My opinion• Comprehensive Intro&discussion section• Two different analyses• Causal relationships b/w long-term training and

related structural changes in specific brain regions

• Future experiments: relative contribution of predisposition and practice

• Different instruments (eg. flute, violin, drum)• Female musicians

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