Background and motivation

We begin by briefly outlining the background and motivation for this book, before giving an overview of each chapter, and pointing out the most significant questions addressed.

Although the methodology used is firmly within the fields of signal processing and mathematical physics, the motivation is interdisciplinary in nature.

The initial open questions that inspired this direction were:

1. (i) How might neurons make use of a phenomenon known as stochastic resonance?

2. (ii) How might a path towards engineering applications inspired by these studies be initiated?

Stochastic resonance and sensory neural coding

Stochastic resonance (SR) is a counter-intuitive phenomenon where the presence of noise in a nonlinear system is essential for optimal system performance. It is not a technique. Instead, it is an effect that might be observed and potentially exploited or induced. It has been observed to occur in many systems, including in both neurons and electronic circuits.

A motivating idea is that since we know the brain is far better at many tasks compared to electronic and computing devices, then maybe we can learn something from the brain. If we can ultimately better understand the possible exploitation of SR in the brain and nervous system, we may also be able to improve aspects of electronic systems.

Although it is important to have an overall vision, in practical terms it is necessary to consider a concrete starting point. This book is particularly focused on an exciting new development in the field of SR, known as suprathreshold stochastic resonance (SSR) (Stocks 2000c). Suprathreshold stochastic resonance occurs in a parallel array of simple threshold devices.