spatial resolution of electrical source localization depends on inter-electrode spacing and signal-to-noise ratio

Extracellular recordings of electrical neuronal sources with non-planar multichannel microelectrodes promise a high spatio-temporal resolution. We have developed signal-based algorithms, simulations and models to inversely estimate neuronal source positions and electrical properties by using multi-sensor recorded extracellular action potentials (EAP). Here, we analyse the dependence of electrode configurations on the position estimation by simulations. Estimations were simulated for various inter-electrode spacings, electrode-source distances and signal-to-noise ratios. The results show that inverse estimation depends on the electrode size or rather on the inter-electrode spacing. We find, as a rule, the larger the spacing, the larger the eligible source location area, but estimation quality of sources which are in the proximity of an electrode contact decreases. In addition, noise worsen the estimation and decreases the assessable distance between source and electrode. Thus, multichannel micro-electrodes should be selected towards signal and spatial sensitivity requirements.