Neuralink Animal Trials: What Happened and Key Outcomes

• Neuralink's animal trials showed monkeys controlling computer cursors and playing Pong using only brain signals.
• Pigs and sheep were used to test whether the implant could record reliably and survive brain motion over long periods.
• The animal work supported the FDA's clearance of human trials in May 2023, though Neuralink's animal testing also drew criticism and federal scrutiny.

Pigs and sheep

Neuralink began its preclinical research with pigs and sheep to test the core technology. In 2020, Elon Musk showed a live pig named Gertrude with a Neuralink implant, and real-time activity from the part of the pig's brain linked to its snout was displayed on screen. The device worked wirelessly and was fully implanted under the skin.

Sheep trials tested durability under movement and helped engineers refine the flexible threads. The early design used 64 ultra-thin threads with 16 electrodes each, and the tests checked that they could withstand brain motion from heartbeat and walking.

Neuralink says it follows the "3 Rs" of animal research (replacement, reduction, and refinement). It built accelerated lifetime testers that simulate years of wear in days, which reduces the number of animals needed.

Pager and Monkey MindPong

In April 2021, a macaque named Pager became the star of "Monkey MindPong." Pager, implanted with the N1 device, played the Atari game Pong using only his thoughts after first learning it with a joystick. The implant recorded activity in his motor cortex, and a decoder turned the intended movements into paddle control.

Later updates reported that, using thought alone, Pager reached 65% and 88% of the median performance of Neuralink employees using a mouse on cursor tasks.

Early trials used "terminal" monkeys that were already near the end of life from other conditions, according to Musk. Elon Musk said in 2023 that no monkey had died as a result of a Neuralink implant; reporting by WIRED and lawmakers disputed this. Institutional Animal Care and Use Committees approve each protocol.

Vision experiments

In March 2024, Musk said Blindsight, Neuralink's planned vision implant, was already working in monkeys, at a low resolution he compared to early video game graphics. Blindsight received an FDA Breakthrough Device Designation in September 2024, and as of October 2026 no human Blindsight trial had launched, according to Neuralink's visual prosthesis page.

Criticism of the animal program

Reuters reported in December 2022 that about 1,500 animals had died in Neuralink's testing since 2018, and the USDA's inspector general opened an investigation. An FDA inspection of Neuralink's California animal lab in June 2023 found record-keeping and quality-control problems, as Reuters reported in early 2024.

The path to human trials

The FDA cleared human trials in May 2023. The first human patient, Noland Arbaugh, controlled a cursor by thought days after his January 2024 surgery, much as Pager had. Neuralink reached about 20 human implants by the end of 2025.

This article was first published in October 2025 and corrected in October 2026; the latest patient count is on the patient table.