THE THEORY OF CENTRAL NERVOUS SYSTEM RECORDING

A large number of biophysical models and quantitative methods are relevant to the design of Brain-Computer Interfaces and other neuroprosthetic devices that rely on recording neural activity in the CNS. These models describe different biological processes occurring across a range of scales. Here we focus on three that appear most relevant to the neural engineer. At the smallest scale we review models of extracellular potential spread around a spiking neuron as they relate to the sources of signal and noise encountered during microelectrode recordings. We overview a variety of signal detection and pattern recognition methods used in an attempt to reliably and automatically detect single unit activity from these recordings. Next, we look at the way the activity of very large populations of neurons aggregates to form the fields measured using far-field recordings from the skull or scalp. We conclude with a review of the representation of dynamic sensory and motor quantities in the activity of spiking neurons and small populations of neurons within the framework of encoding models and decoding methods.