CIF: Small: Advanced Ion Channel Models for Neurological Signal Processing -- Theory and Application to Brain-Computer Interfacing

The University Of Central Florida Board Of Trustees, Orlando FL

Investigators

Abstract

The investigators are studying the scientific theory and engineering consequences of the electrical noise signals generated by neurons inside the brain. They are developing a deeper understanding of this neuronal noise primarily to improve brain-computer interfaces (BCIs), which enhance the quality of life of patients with various paralyzing disabilities such as Lou Gehrig?s disease. By understanding the statistical characteristics of the background noise, they are able to reduce its interference with the conscious signal generated by the brain of the paralyzed patient. This creates a much more reliable control signal for wheelchairs, customized internet browsers, and the home environment. In addition, the investigators are applying their advanced neuron models to gain insight into non-diseased brain tissue and the processes by which it creates and transmits information. This promises to have significant implications for understanding the functioning of both natural and synthetic neural networks. Specifically, the investigators have developed a novel mathematical and stochastic model for neuronal ion channels that takes into account quantum mechanical and thermodynamic considerations. The principle of entropy maximization applied to a population of these quantum ion channels in thermal equilibrium explains the ubiquitous presence of the so-called 1/f-noise in neural and electroencephalographic (EEG) recordings. The parameters derived from these models are combined with a new signal processing paradigm called octave-averaged spectral rectification to dramatically reduce the interfering effect of 1/f-noise on EEG signals. As a result, the stimulus frequencies of an experimental type of brain interface called steady-state visual evoked potential (SSVEP) BCIs can be increased into the high-gamma band above 30Hz. This dramatically reduces the negative side effects of these SSVEP BCIs and makes them of practical use for the first time to paralyzed patients as well as heads-up displays for pilots and surgeons, and high-performance game control.