Sci-Fi author Philip K. Dick wrote of a world in which people could select their moods every day on a “Penfield mood organ.” We're a long way from building that device, but there are already machines that can alter your brain.
One example is a transcranial magnetic stimulation (TMS) machine. When held to your head, it can affect areas of the brain within a few centimeters of the surface. TMS doesn't reach the deeper regions of the brain, but there are a lot of important and interesting areas in the cortex where TMS delivers its current. Clinicians use it to treat migraines and depression, among other things.
TMS has been around for barely 20 years, and shows enormous potential for certain types of neural conditions.
“Neuroengineering” raises a number of ethical issues, especially considering that scientists are already working on a version of a TMS machine that is an affordable, wearable unit. It could go into much wider use in regular therapy offices, or even at home, allowing people to “hack” their own brains.
For an in-depth look at this fascinating subject, click the link to the Wired Magazine article below.