Important components of the Extracellular Field (EF) can be caused by a sequential or moving depolarization generated by some cell-groups at specific sub-regions. These depolarizations can be sensed not only by man-made techniques -as electroencephalography (EEG) and electrocardiography (ECG) - but also by some physiological processes associated to ephaptic interactions. METHODS: Based on principles of electromagnetism we implement two computer simulations where this can be studied: 1. Bilateral waves, where subregions can have up to 3 mesoscopic states: activated, resting or sleeping (hyperpolarized) and 2. Stochastic propagation without deactivation. RESULTS: Biphasic, Gaussian and Mexican hat functions can be generated by these models. CONCLUSIONS: (i) Mesoscopic minimalistic models can explain in a simple way some electrophysiological signals. (ii) We suggest an analogy between mechanisms used in animal and robots to detect visual motion and engineering techniques to detect moving depolarizations in the nervous system. Similarly, such mechanisms might exist in cell-groups. (iii) Distorted waves can cause pathologies and their modulation by electric or magnetic stimulation can be potentially beneficial.