Sensing millimeter-scale dynamics in cortical surface potentials for neural prosthetics

A brain signal sensor consisting of an array of millimeter-spaced platinum microwire electrodes was characterized as a recording medium for a brain-machine interface. The small physical size of the electrodes and tight grid spacing constitute a novel approach for applications which depend on the ability to accurately capture the spatiotemporal dynamics of neural activity. Because their geometry approaches the scale of the underlying structures of cortical information processing, microwire grids offer high signal fidelity for the inherent implantation risks. Characterization of the recording properties of these electrodes and of data recorded from multiple functional areas of human neocortex support the claim that millimeter-scale dynamics are present in cortical surface potentials and may be important to the performance of brain-computer interface applications.