1. A method for assessing neural activity in a neural region having multiple subfields, the method comprising: evoking a cellular electrical response in at least one subfield due to neural activity in the neural region; capturing image data of the cellular electrical response at a level sufficiently detailed in space and time to differentiate between polarization-based events of two respective portions of the subfield; assessing neural activity by correlating space and time information, from the captured data, for the two respective portions of the sub-field.