In one embodiment, a system for stimulating neurons of a patient in vivo is provided herein. The system includes a first energy emitting component positioned external to the patient configured to generate a first energy stimulus, and a second energy emitting component positioned external to the patient configured to generate a second energy stimulus, wherein the first energy stimulus comprises an intensity level below a predetermined threshold required to stimulate the neurons, and wherein the second energy stimulus comprises an intensity level below a predetermined threshold required to stimulate the neurons; wherein a combination of the first and second energy stimuli at a target location in a target tissue of a patient comprises an intensity level at or above a predetermined threshold required to stimulate the neurons in the target tissue and prevent the stimulation of neurons outside the target location.