UCSF scientists have been at the forefront in the development of the cochlear implant since its evolution, beginning in the 1950s. The late Robin Michelson, MD, of UCSF, was one of three scientists worldwide that created and implanted single-channel cochlear devices in human volunteers in the early 1970s. In the 1980s, UCSF neuroscientist Michael Merzenich, PhD, was one of the pioneers of the development of multichannel cochlear implants, which enabled profoundly deaf people to understand normal speech. The development of the the UCSF multichannel implant (later manufactured by Advanced Bionics Corporation) resulted from a combination of bioengineering and device safety studies and basic research studies conducted in animals that revealed how to artificially control the patterned stimulation of the acoustic nerve, to simulate patterns representing speech in the normal ear. Merzenich’s research helped pioneer the concept that the sensory pathways in the nervous system are not necessarily fixed soon after birth, but change with experience throughout life. This capacity is known as “neuroplasticity.” This remarkable capability for change largely accounts for the success of cochlear implant application, because after introduction of the device in a child or adult, the brain can adjust to these artificial inputs to create a remarkably normal aural language processing ability. The cochlear implant is still the most technologically sophisticated neuroprosthesis ever created. It was the first of Merzenich’s many subsequent efforts, now in high gear, to develop techniques for treating traumatic disorders and diseases based on the concept of neuroplasticity. In the 1990s, Merzenich developed software programs for language and learning disabilities, and is currently exploring software-based programs for overcoming the deficits that accompany normal and pathological aging, schizophrenia, Parkinson’s disease, traumatic brain injury, damage accompanying brain infections or chemotherapy, and stroke.