What if we could use brain waves to treat Alzheimer's? Professor and neuroscientist Li-Huei Tsai details a promising new approach to artificially stimulate gamma brain waves using light and sound therapy, to increase connectivity and synchrony and delay the onset of this deadly disease. This non-invasive therapy has already been shown to work in mice -- now it's on to human clinical trials, with the potential to usher in a brighter future for everyone. (Followed by a Q&A with head of TED Chris Anderson)