The brain’s capacity for finding new information- processing pathways is thought to explain the success of artificial cochleas, which have been implanted in the ears of approximately 100,000 hearing-impaired people around the world. They typically have an array of electrodes, each of which channels electrical signals toward the auditory nerve. The electrodes can stimulate not just a single neuron in the brain but many simultaneously. When cochlear implants first appeared in the 1980s, many neuroscientists expected them to work poorly, given their primitive design. But the devices work well enough for some deaf people to converse over the telephone, particularly after an adjustment period during which channel settings are fine-tuned to provide the best reception. Patients’ brains somehow figure out how to make the most out of the strange signals. The surprising effectiveness of artificial cochleas – together with other evidence of the brain’s adaptability – has fuelled optimism about the prospects for brain/machine substitution. A case in point is an ongoing project at the University of Southern California that seeks to create implantable brain chips that can restore or enhance memory.