Various aspects are directed to systems and methods for assessing neural activity of a neural region having multiple subfields. In certain embodiments, a method includes evoking a cellular electrical response in at least one subfield due to neural activity in the neural region, capturing image data of the electrical response at a level sufficiently detailed in space and time to differentiate between polarization-based events of two respective portions of the subfield, and then assessing neural activity by correlating space and time information, from the captured data, for the two respective portions of the sub-field. Other more specific aspects of the invention involve different preparation and neural stimulation approaches which can vary depending on the application.