Elon Musk’s brain-chip company Neuralink is facing a legal challenge from an animal rights group that has accused the company of subjecting monkeys to “extreme suffering” during years of gruesome experiments. Xinhua News Agency via Getty ImaElon Musk’s Neuralink conducted gruesome tests on monkeys for years, according to a new complaint from an animal rights group. Elon Musk wants to start human testing of Neuralink brain chips this year. The organization is accusing Neuralink and UC Davis of nine violations of the federal Animal Welfare Act — a federal measure designed to reduce suffering during animal experiments. Elon Musk says Neuralink will one day cure paralysis and make humans smarter.