The neural correlates of bimanual motor learning: Neurometabolites, synaptic density, and effective premotor–motor connectivity

Abstract

Human movement, and particularly bimanual motor control, which involves coordinating both hands, is fundamental to our everyday lives, for example when getting dressed, driving a car, or playing a musical instrument. Acquiring new motor skills relies heavily on motor learning and neuroplasticity. Hence, understanding the neural mechanisms behind these processes is essential for ultimately optimizing training interventions and rehabilitation strategies. This PhD research aimed to enhance our understanding of the neural correlates underlying bimanual motor learning and neuroplasticity in the human brain. Through various techniques such as magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and dual-site transcranial magnetic stimulation (dsTMS), we explored changes in neurotransmitter levels, synaptic density, and connectivity between key brain regions involved in motor function. The findings have enhanced our understanding of the relationship between motor learning on the one hand, and neurotransmitters and synaptic density on the other hand. Furthermore, a novel dsTMS setup has been validated to study the effective connectivity between the motor-related brain regions with a focus on dorsal premotor cortex (PMd) and primary motor cortex (M1) in the context of motor learning.