Scientists at the Institute of Molecular Biotechnology of the Austrian Academy of Sciences used embryonic stem cells to grow a pea-sized miniature brain. The scientists used either embryonic stem cells or adult skin cells to produce the part of an embryo that develops into the brain and spinal cord - the neuroectoderm. They placed this mass of cells in a nutrient gel environment, and watched the cells grow into a structure similar to the brain of a nine-week old fetus.
Stories about this development mentioned that one day a technique such as this could be used to treat people with brain damage. But we may look ahead to more radical technical developments that could one day result from this type of scientific work.
One radical possibility is that we may one day be able to create small supplemental brains that people could use to add additional functionality to their existing brains. It's a simple idea: grow a small supplemental brain in the lab, and then somehow connect it to the existing brain.
Older readers may remember the days of big box personal computers with 8 plug in slots. You could make your computer smarter just by opening it up with a screwdriver, and then sliding in an electronic card into one of the slots.
One problem with human biology, however, is that the skull does not have any empty space in which you could put in a supplemental lab-grown miniature brain the size of a few walnuts. But there may be a way around that difficulty: put the supplemental miniature brains outside of the skull.
Below is a visualization of how this might look. The man of the future is wearing a Brain Band that has on its left and right two small plastic half spheres. Each half sphere has within it a miniature lab-grown brain. The brains are connected to a strong circular metal band that wraps around the man's forehead. The metal band has the sole purpose of providing structural support for the half spheres.
Each of the two miniature brains are connected to the man's main brain. To achieve such a connection it would be necessary to drill two holes in the skull, and to have wire-like nerves passing through these holes, to connect the central brain and the two supplemental brains. This would involve nothing particularly difficult from a technical standpoint. We already have nerves stretching much longer distances (such as the nerves that allow your brain to command your toes to wiggle). Presumably if scientists are able to lab-grow miniature brains, it would be relatively easy for them to grow nerves of a few centimeters that could stretch from just outside the forehead, through a hole in the skull, into the brain.
Giving a human these two supplemental brains would not involve any terribly complicated operation. After the two miniature brains were grown in the lab, they could each be fitted in a semi-spherical protective unit, and attached to a head band. Two small holes would be drilled in the skull, and some type of connecting nerve could be inserted to stretch the short distance from the miniature brains to the outer part of the interior brain, with the nerve passing through the holes.
I imagine that if a person woke up from such an operation, he would not immediately feel his brain was much different. It might take quite some while, perhaps months or years, for the person to be able to make use of the additional brain functionality. It might require a long period of brain training, and might also require quite a bit of time for additional nerve connections to form between the two supplemental brains and the person's main brain. The person who had such an operation might be given some drug or injections that would speed up the forming of such connections.
Would people act with revulsion upon seeing a man with two supplemental brains? Perhaps. But there would be advantages. When the person with two supplemental brains went in to interview for a job requiring heavy brain power (such as Wall Street derivative analyst job), the man's appearance would create a strong “super-Einstein” impression that would improve the odds of the person getting the job.