Disadvantages of rate coding

For rate coding that counts is firing frequency, therefore a single action potential (AP) carries no information. A minimum of two APs is essential as instantaneous frequency can then be derived from the interspike interval, the time between two consecutive APs. Given that the noise and inherent variability of neurons, two or three APs might not precisely encode information about stimulus intensity. For precision sufficient time should elapse to sample a reasonable number of APs. Therefore for neural systems making quick decisions, that is, brief integration times, the precision of stimulus intensity encoding is sacrificed. This problem is partially solved by the population coding that temporarily samples simultaneous output of many neurons carrying the similar information.

Additionally, separate neurons are temporal integrators therfeore cannot convey information about the exact timing of events. Accurate timing needs temporal coding in ensembles of the neurons.