We propose a simple theoretical structure of interacting integrate-and
-fire neurons that can handle fast information processing and may acco
unt for the fact that only a few neuronal spikes suffice to transmit i
nformation in the brain. Using integrate-and-fire neurons that are sub
jected to individual noise and to a common external input, we calculat
e their first passage time (FPT), or interspike interval. We suggest u
sing a population average for evaluating the FPT that represents the d
esired information. Instantaneous lateral excitation among these neuro
ns helps the analysis. By employing a second layer of neurons with var
iable connections to the first layer, we represent the strength of the
input by the number of output neurons that fire, thus decoding the te
mporal information. Such a model can easily lead to a logarithmic rela
tion as in Weber's law. The latter follows naturally from information
maximization if the input strength is statistically distributed accord
ing to an approximate inverse law.