Neurobiological systems operate at power levels that are unattainable by modern electronic systems while exhibiting broader information processing capabilities for a number of important tasks. A variety of engineered systems designed for energy efficiency or hardware simplicity use time-based signal representations, which share similar mathematical principles with those that arise naturally in biology. In general, time-based signal representations refer to embedding information into the timing, density, or duration of a predetermined, and often bipolar, waveform. In mammalian nervous systems, it is generally accepted that neurons embed information into the timing and firing density of the sudden changes in their membrane potential, or spikes. Similarly, many low-power electronic systems use signal representations that embed information in the timing, repetition frequency, or duration of simple pulse waveforms. Despite their apparent similarities, such signal representations are often studied in different contexts.