Information Processing Mechanisms in the Mammalian Brain: Analysis of Spatio-temporal Neural Response in the Auditory Cortex

Abstract

The mammalian brain can be regarded as a huge and complicated dynamical information processing system composed of single units called neurons or nerve cells. The mechanisms of brain function have, traditionally, been elucidated with the aid of single microelectrodes to measure the responses in single neurons. This approach, however, seems to be insufficient for identifying the complex dynamical system as the brain. An optical recording method, on the other hand, has made possible real-time multipoint measurement of the evoked neural activities distributed in the brain. This new recording method can be used to explore new mechanisms responsible for the dynamical neural processing activities of the brain. Such neural activities always exhibit nonlinear and nonstationary characteristics, and so straight forward application of any system identification theory to the neural system is inappropriate. On the other hand, many industrial dynamical systems, which involve nonstationary and nonlinear dynamical phenomena, exquisitely are modeled and controlled by using the extensive linear theory regarding to system identification and control. From this fact, there is a possibility that a linear identification theory such as time series analysis could be used in exploring the functioning of a nonlinear and nonstationary brain.