Penalty Kicks, Neural Networks, Brains and Neural Coding
(Studies in Human Motor Control)

Penalty Kicks:  Movement is a fundamental aspect of everyday life, we are constantly responding to and reacting with our environment. Many areas of the human nervous system are involved in controlling our actions.
 

Part of my research is concerned with the question of how we initiate, control and co-ordinate movements.

This is the field of Human Motor Control.

Francesco Toldo saves a Frank de Boer penalty
The importance of being co-ordinated: Italy's
Francesco Toldo saves a penalty during Euro 2000

Neural Networks:  How does the central nervous system generate the necessary signals to control and co-ordinate different muscles during voluntary movements?

Electrical  activity in the central nervous system can be recorded and analyzed to study how neural networks in different parts of the central nervous system communicate and interact during voluntary movements.

Analysis of simultaneous recordings of Electroencephalography (EEG) from the surface of the scalp over the motor cortex and Electromyograms (EMG) from the muscle body can be used to investigate how the brain and spinal cord interact when we move.
 

EEG and EMG records during wrist extension/flexion
Sample records of EEG and EMG from a subject making ramp and hold movements about the wrist joint

EEG provides a measure of the activity in a group of cells in a specific brain region. EMG is an indicator of the activity of motoneurone cells in the spinal cord.

The above signals are typical of those obtained in experimental neurophysiology. A ubiquitous feature of neural systems is the presence of noise at all levels. Analysis of such data requires some form of statistical framework to characterise these signals and their interaction.

I have developed a Fourier based Statistical Signal Processing framework for analysis of such stochastic neural data which can be used to characterise neural signals and their interactions.

Application of these Signal Processing techniques can be used to investigate how the brain and spinal cord interact during the above movement.
 
Coherence and Phase estimates between EEG and rectified EMG
Frequency (Hz)
Magnitude and Phase information obtained using a Statistical Analysis of the correlation between EEG and rectified EMG. Analysis of EEG and extensor EMG during periods of maintained position holding.

This analysis indicates the presence of 20-30 Hz phase locked oscillations between the neural networks of the brain and spinal cord during the position holding phase of the task.

Brains and Neural Coding
The question of how groups of cells communicate is central to our understanding of how the human brain represents and processes information.

Phase locked oscillations such as those illustrated above may play a role in transmitting information within and between the neural networks of the brain. 

Results from analysis of experiments, similar to that illustrated above, can be combined with Neural Modelling studies to provide insight into how information is represented and processed in the brain.

 

Human Brain

Need More Details?
For further details of the studies on oscillations in the human motor system see the Motor Control references and reprints on the publications page

Next: Multivariate Fourier analysis of neural data

Home Page

Last Modified 05 July 2002