Models for Cooperative Neuronal Dynamics underlying Planning and Execution of Movements

The control of motor behavior in primates is based on multiple representations of motor actions in several areas of the central nervous system. Despite a wealth of physiological and anatomical data no clear concept has emerged yet how the distributed neuronal networks of the motor system dynamically organize and coordinate their activity in space and time during the planning and execution of movements.

In fact, a number of different neuronal coding schemes based on different types of network dynamics are currently discussed in the literature [1, 2, 3]. The modeling of neuronal dynamics on different levels of abstraction is, therefore, an important research tool to explore the potential of the various candidate codes for motor control and to gain insight into the possible interaction of different coexisting schemes.

The principal research goal of this theoretical project [4] is to gain insight into the fundamental properties of dynamic cooperative activity across all major stations of the cortico-spinal motor pathway. On the basis of electrophysiological recordings from multiple single neurons in the motor system of monkeys performing a complex movement task, models will be constructed and analyzed for their dynamic properties with mathematical tools and computer simulations. The types of models range from biology-oriented neuronal networks to more abstract dynamical systems describing certain functional submodules. By critically testing the models against experimental findings this project will explore the potential of the various candidate neuronal coding schemes for motor control and gain insight into the interaction of coexisting schemes within and across different parts of the motor system.

It is our goal to contribute to the answers of the following important questions: What are the specific properties of neuronal cooperativity in the central motor system ? What could be the use of synchronized activity in diverging-converging groups of neurons for the planning and execution of movements ? What is the role of feedback for the dynamics of motor networks ? Does the concept of a functional module make sense in the motor system at all or can its dynamics only be understood as that of a distributed cooperative network ?
Model predictions which go beyond the experimental findings will be evaluated for the planning of new experiments and eventually contribute to the further refinement of the models.

This project is supported by a PhD scholarship from the Boehringer Ingelheim Fonds.