Noland Arbaugh, a 29-year-old quadriplegic (paralysed in all four limbs), has demonstrated the ability to play chess with just his mind using Elon Musk's Neuralink chip implanted in his brain. Arbaugh had suffered injuries in a diving accident around eight years ago that led to paralysis from the shoulder down. Neuralink chip was surgically implanted in his brain in January.