This amazing video demonstrates the effect of deep brain stimulation (DBS), a surgical treatment of disorders like Parkinson’s where transmitters are implanted in the brain and operated via remote:
Essentially, DBS is a brain pacemaker. Its job is to ameliorate the abnormal firing of neurons that underlies Parkinson’s, essential tremor, and so on. In preparation for surgery, a neurologist uses imaging technology to locate the problematic brain structure, which in the case of Parkinson’s is the subthalamic nucleus (STN). A dime-sized hole is then drilled into the skull and an electrode is affixed to the appropriate target in the brain. The electrode is then connected to a wire that is threaded under the skin down towards the chest where a programmable battery is implanted. Once the two connect, it is possible to normalize neurological activity by delivering electrical impulses directly to the brain.
The whole setup can be controlled by the patient or doctor via a handheld remote. The remote can turn the DBS on and off, which is how you get the dramatic effects you see in Johnson’s clip.