The Science Behind Extinction

Extinction by Mark Alpert

The development of brain-machine interfaces, which link the human mind to microchips, sensors, and motors, is one of the most momentous trends in twenty-first-century science. Here are some of the real technologies highlighted in Extinction.

Powerful Prostheses. In 2011 researchers at the University of Pittsburgh conducted one of the first human trials of a prosthetic arm guided by the user's thoughts. The scientists implanted an array of electrodes on the surface of the brain of Tim Hemmes, a thirty-year-old paralyzed in a motorcycle accident seven years before. By sensing the brain-cell firing patterns that correspond to specific arm motions, the device enabled Hemmes to mentally send commands to a nine-pound prosthesis and move its hand and fingers. The research is partly funded by DARPA, the Pentagon's R&D agency, which has invested $100 million to develop better artificial limbs.

Artificial Eyes. Researchers have given eyesight to the blind by linking a video camera to an implant attached to the retina. The camera wirelessly transmits its video to the implant, which reproduces the images on a grid of electrodes. The electrodes stimulate the adjacent nerve cells in the damaged retina, and the pattern of nerve signals conveys a rough picture to the brain. Second Sight Medical Products has already introduced the first commercial retinal implants in Europe, and the device may soon become available in the United States as well.

Cyborg Swarms. Spurred by funding from DARPA, scientists have developed the first "bugs with bugs"— insects with implanted electronics designed to turn them into remote-controlled surveillance drones. By transmitting radio signals to electrodes attached to the brains and flight muscles of beetles, researchers at the University of California, Berkeley, steered the insects left and right as they flew across the lab (see "Cyborg Beetles" in Scientific American, December 2010). At Cornell University, scientists inserted tiny half-gram circuit boards into the pupae of moths; when the adult insects emerged from their chrysalises, the electronics were embedded in their bodies next to their flight muscles.

The Singularity. A growing number of so-called Singularitarians, inspired by the writings of futurist Ray Kurzweil and others, believe that people will achieve immortality in this century by downloading the contents of their minds into advanced computers. Although many scientists scoff at this prediction, researchers demonstrated in 2011 that they could extract memory traces from the brains of rats. Implanted electrodes recorded signals in the hippocampus, a brain region involved in forming memories, while the rats performed a simple task. When the researchers replayed the signals later in the rats' brains, it helped the animals remember the task.

What is Consciousness? Speculation about the nature of consciousness has long been the province of philosophers, but in recent years neuroscientists have tried to answer the question using brain-imaging experiments and other studies. One hypothesis is that the synchronization of signals from various regions of the brain generates the experience of consciousness. The region called the thalamus may play a vital role because it relays so many of the brain's signals.

Supreme Harmony. China is already building surveillance networks similar to the ones described in Extinction. By 2014 the city of Chongqing plans to install half a million surveillance cameras linked by servers that will store the video and distribute it to police officials. The ostensible purpose of the network is to fight crime, but human-rights advocates say the Chinese government can also use it to identify dissidents. In July 2011, The Wall Street Journal reported that three U.S. companies were seeking to get involved in assembling the network.