  An expression for the group delay of the FitzHugh-Nagumo model in response to
low amplitude input is obtained by linearisation of the cubic term of the
voltage equation around its stable fixed-point. It is found that a negative
group delay exists for low frequencies, indicating that the evolution of slowly
fluctuating signals are anticipated by the voltage dynamics. The effects of the
group delay for different types of signals are shown numerically for the
non-linearised FitzHugh-Nagumo model, and some observations on the signal
aspects that are anticipated are stated.
