Neural coupling limits independence of bimanual hand movements: Can this be overcome by learning?

This project is based on the knowledge that cooperative hand movements (e.g. opening a bottle) are based on a neural coupling (Dietz et al. 2015). Meanwhile we discovered that during bimanual movements the corrective reactions to a unilateral displacement induced by arm nerve stimulation appear on both sides with the same reflex amplitude (Thomas et al. 2018). These observations imply that a neural coupling determines bilateral hand movements and that not only the contralateral but also the ipsilateral hemisphere is involved in their control. Further studies indicated that most bimanual movements used during daily life activities are coupled, i.e. performed in synchrony. In an artificial task which requires independent and asynchronous hand movements (tracking a sinusoidal trajectory displayed on a screen by hand dorsiflexion movements with differing frequency between the left and right side) the movement errors were much larger than during synchronous movements. The performance accuracy will be related to the strength of neural coupling of the hands. In this project it is foreseen to further explore the influence of neural coupling on bilateral hand movements and to investigate the following research questions: 1. To what extent can the neural coupling be suppressed by training of asynchronous hand movements, i.e. can the movement error of asynchronous movements be reduced by attenuation of the neural coupling? 2. Is there a difference in the acquisition of independent hand movements between young and elderly subjects; and, 3. Can people who have trained independent hand movements early in their life, e.g. by playing piano or percussion instruments, more easily decrease the neural coupling between the two hands?

This project is based on the knowledge that cooperative hand movements (e.g. opening a bottle) are based on a neural coupling (Dietz et al. 2015). Meanwhile we discovered that during bimanual movements the corrective reactions to a unilateral displacement induced by arm nerve stimulation appear on both sides with the same reflex amplitude (Thomas et al. 2018). These observations imply that a neural coupling determines bilateral hand movements and that not only the contralateral but also the ipsilateral hemisphere is involved in their control. Further studies indicated that most bimanual movements used during daily life activities are coupled, i.e. performed in synchrony. In an artificial task which requires independent and asynchronous hand movements (tracking a sinusoidal trajectory displayed on a screen by hand dorsiflexion movements with differing frequency between the left and right side) the movement errors were much larger than during synchronous movements. The performance accuracy will be related to the strength of neural coupling of the hands.
In this project it is foreseen to further explore the influence of neural coupling on bilateral hand movements and to investigate the following research questions: 1. To what extent can the neural coupling be suppressed by training of asynchronous hand movements, i.e. can the movement error of asynchronous movements be reduced by attenuation of the neural coupling? 2. Is there a difference in the acquisition of independent hand movements between young and elderly subjects; and, 3. Can people who have trained independent hand movements early in their life, e.g. by playing piano or percussion instruments, more easily decrease the neural coupling between the two hands?

1. The aim of this project is to explore in how far the neural coupling between the hands is fixed and limits independent hand movements and which factors can influence this mechanism.

1. The aim of this project is to explore in how far the neural coupling between the hands is fixed and limits independent hand movements and which factors can influence this mechanism.

The technical task in this project consists of recordings of electrical muscle activity (electromyography) and reflex responses to non-noxious arm nerve stimulations by surface electrodes placed over the skin of both forearms during various synchronous and asynchronous hand movements. These recordings have to be evaluated and analyzed. The learning effects can be assessed by the calculation of a relationship between movement performance (kinematics) and strength of neural coupling.

The technical task in this project consists of recordings of electrical muscle activity (electromyography) and reflex responses to non-noxious arm nerve stimulations by surface electrodes placed over the skin of both forearms during various synchronous and asynchronous hand movements. These recordings have to be evaluated and analyzed. The learning effects can be assessed by the calculation of a relationship between movement performance (kinematics) and strength of neural coupling.

Master thesis project in Health Sciences and Technology

Master thesis project in Health Sciences and Technology

- Prof. em. Dr Volker Dietz, FRCP, FEAN University Hospital Balgrist, volker.dietz@balgrist.ch - Prof. Dr Roger Gassert roger.gassert@hest.ethz.ch, Advisor ETHZ

- Prof. em. Dr Volker Dietz, FRCP, FEAN University Hospital Balgrist, volker.dietz@balgrist.ch
- Prof. Dr Roger Gassert roger.gassert@hest.ethz.ch, Advisor ETHZ