Early this April, when researchers at Washington University in St. Louis reported that a woman with a host of electrodes temporarily positioned over the speech center of her brain was able to move a computer cursor on a screen simply by thinking but not pronouncing certain sounds, it seemed like the Singularity—the long-standing science fiction dream of melding man and machine to create a better species—might have arrived. At Brown University around the same time, scientists successfully tested a different kind of brain–computer interface (BCI) called BrainGate, which allowed a paralyzed woman to move a cursor, again just by thinking. Meanwhile, at USC, a team of biomedical engineers announced that they had successfully used carbon nanotubes to build a functioning synapse—the junction at which signals pass from one nerve cell to another—which marked the first step in their long march to construct a synthetic brain. On the same campus, Dr. Theodore Berger, who has been on his own path to make a neural prosthetic for more than three decades, has begun to implant a device into rats that bypasses a damaged hippocampus in the brain and works in its place.

The hippocampus is crucial to memory formation, and Berger’s invention holds the promise of overcoming problems related to both normal memory loss that comes from aging and pathological memory loss associated with diseases like Alzheimer’s. Similarly, the work being done at Brown and Washington University suggests the possibility of restoring mobility to those who are paralyzed and giving voice to those who have been robbed by illness or injury of the ability to communicate. If this is the Singularity, it looks not just benign but beneficent.

Michael Chorost is a man who has benefited from a brain–computer interface, though the kind of BCI implanted in his head after he went deaf in 2001, a cochlear implant, was not inserted directly into his brain, but into each of his inner ears. The result, after a lifetime of first being hard of hearing and then shut in complete auditory solitude, as he recounted in his memoir, Rebuilt: How Becoming Part Computer Made Me More Human (2005), was dramatic and life-changing. As his new, oddly jejune book, World Wide Mind: The Coming Integration of Humanity, Machines, and the Internet, makes clear, he is now a cheerleader for the rest of us getting kitted out with our own, truly personal, in-brain computers. In Chorost’s ideal world, which he lays out with the unequivocal zeal of a convert, we will all be connected directly to the Internet via a neural implant, so that the Internet “would become seamlessly part of us, as natural and simple to use as our own hands.”

The debate between repair and enhancement is long-standing in medicine (and sports, and education, and genetics), though it gets louder and more…