Neural Systems Do Not Evenly Sample Signals
[I]t is standard practise in communications theory to assume that incoming signals are evenly sampled over the range of the signal. A number of optimal decoding strategies have been devised that take advantage of this particular kind of sampling. However, this kind of sampling is clearly not present in neural systems. Sampling densities often change over the range of the signal, and the particular sample points can be quite different even between two members of the same species. This is because neurons are diverse, unlike the typical components of artificial communication systems.
-- Chris Eliasmith , Charles H. Anderson
from "Neural Engineering: Computation, Representation, and Dynamics in Neurobiological Systems"
Quoted on Sat Dec 15th, 2012