One of the most ambitious efforts to scale up to more neurons is Elon Musk’s Neuralink, which implants a large set of threadlike electrodes simultaneously.[175] A test in lab rats demonstrated a readout of 1,500 electrodes, as opposed to the hundreds that have been employed in other projects.[176] Later, a monkey implanted with the device was able to use it to play the video game Pong.[177] Following a period of regulatory challenges, Neuralink received FDA approval to begin human trials in 2023 and, just as this book went to press, implanted its first 1,024-electrode device in a human.[178]
