Well, that's a cool thought: current DBS leads do have multiple contacts. However, the main reason for this is that exact placement of the leads is not possible

Well, that's a cool thought: current DBS leads do have multiple contacts. However, the main reason for this is that exact placement of the leads is not possible. Even with structural MRI and CT scans and so on, the placement is only approximate. So, surgeons have the patient awake and talking etc. to make sure they are not hitting the internal capsule (which would be bad for movement etc.) and then have access to multiple leads which they activate in turn to see which leads are best at mitigating symptoms (i.e. are activating/deactivating the appropriate structure) What I am very excited about is the concept of neurotrophic chemicals on electrode leads. These chemicals encourage neurons to grow processes towards them, thereby making a better and longer lasting connection with the electrode. If we ever get to a Neuromancer/Matrix like future where we 'jack in' our brains, I think neurotrophic electrodes with very fine spacing will be part of the technology, so that we can activate many neurons in many different patterns in a well controlled manner.