Motor cortex and hand motor skills: Structural compliance in the human brain

Abstract

Recent studies in humans and nonhuman primates have shown that the functional organization of the human sensorimotor cortex changes following sensory stimulation or following the acquisition of motor skills. It is unknown whether functional plasticity in response to the acquisition of new motor skills and the continued performance of complicated bimanual movements for years is associated with structural changes in the organization of the motor cortex. Professional musicians, especially keyboard and string players, are a prototypical group for investigating these changes in the human brain. Using magnetic resonance images, we measured the length of the posterior wall of the precentral gyrus bordering the central sulcus (intrasulcal length of the precentral gyrus, ILPG) in horizontal sections through both hemispheres of right-handed keyboard players and of an age-and handedness-matched control group. Lacking a direct in vivo measurement of the primary motor cortex in humans, we assumed that the ILPG is a measure of the size of the primary motor cortex. Left-right asymmetry in the ILPG was analyzed and compared between both groups. Whereas controls exhibited a pronounced left-larger-than-right asymmetry , keyboard players had more symmetrical ILPG. The most pronounced differences in ILPG between keyboard players and controls were seen in the most dorsal part of the presumed cortical hand representation of both hemispheres. This was especially true in the nondominant right hemispheres. The size of the ILPG was negatively correlated with age of commencement of musical training in keyboard players, supporting our hypothesis that the human motor cortex can exhibit functionally induced and long-lasting structural adaptations.

Cerebral Asymmetry: A Quantitative, Multifactorial, and Plastic Brain Phenotype

“…Furthermore, given the relatively small sample size and diversity of age ranges in the cohorts of these studies (listed in Table 2), further investigation and replication may be needed in order to validate some of their conclusions. For instance, the greater symmetry of the central sulcus in professional keyboard players, originally reported by Amunts et al (1997) was independently replicated 13 years later in a group of Chinese musicians by Li et al (2010). Longitudinal studies and larger datasets will be crucial to shedding light on the mechanisms that mediate interhemispheric structural plasticity in the brain.…”

“…For instance, an analysis of the planum temporale in professional musicians with and without perfect pitch, and non-musician controls (Schlaug et al, 1995) found that musicians with perfect pitch displayed up to twice as much asymmetry compared with musicians without perfect pitch and controls, primarily due to a smaller volume on the right hemisphere (Keenan et al, 2001). A prior study had found that right-handed male professional keyboard players exhibited greater symmetry in the central sulcus, as compared to age-matched controls (Amunts et al, 1997). In addition, the depth of the sulcus was negatively correlated with the age at which musicians began bimanual training (Amunts et al, 1997).…”

The effects of musical training on movement pre-programming and re-programming abilities: An event-related potential investigation

“…Indeed, neuroimaging studies indicate that professional musicians exhibit larger grey matter volume in the primary motor cortex (Amunts et al, 1997;Gaser & Schlaug, 2003;Elbert et al, 1995) and cerebellum (Hutchinson et al, 2003), relative to non-musicians. Furthermore, structural enlargements in the primary motor cortex (M1) appear to correspond to the type of instrument that an individual specializes in (Elbert et al, 1995;Bangert & Schlaug, 2006).…”

Effect of mindfulness meditation on brain–computer interface performance

“…This population began their practice in childhood thereafter practiced intensely for many years. Researchers have suggested that the differences observed between musicians and nonmusicians were related to long-term and intensive practice on a musical instrument (Gaser & Schlaug, 2003;Norton et al, 2005) and early commencement of practice (Amunts et al, 1997;Watanabe, Savion-Lemieux, & Penhune, 2007).…”

“…Studies also found that musicians have performed better than non-musicians on auditory processing (Chartrand & Belin, 2006;Špajdel, Jariabková, & Riečanský, 2007;Strait, Kraus, Parbery-Clark, & Ashley, 2010) and fine motor abilities (Amunts et al, 1997;Hughes & Franz, 2007;Spilka, Steele, & Penhune, 2010).…”