The company had released a video in March showing the patient playing chess "online" with his mind, without mentioning the incident.

This clarification came on its blog after revelations from the Wall Street Journal, reported this Thursday by the France-Presse (AFP) agency.

Noland Arbaugh, 29, a quadriplegic since a diving accident, received Neuralink's N1 implant in January -- the first implantation of the device in a human being.

But "in the weeks following surgery, several wires retracted from the brain, resulting in a significant reduction in the number of usable electrodes," the 'start-up' explained.

The wires are coated with electrodes that capture neural signals. Arbaugh's ability to control the cursor on the screen, therefore, decreased.

"In response to this change, we modified the recording algorithm to be more sensitive to the signals, improved the techniques for translating those signals into cursor movements, and enhanced the user interface," Neuralink explained, explaining that the control features through the implant now exceeded "Noland's baseline performance".

In March, Noland Arbaugh was amazed by his new 'powers'.

"It's so spectacular. There's still a lot to do, but it's already changed my life," he said, smiling, in a video broadcast live by Neuralink.

According to the Californian company, the patient now spends almost 70 hours a week using the device, half of the time in tests related to clinical trials, and the other half in personal activities, from video games to foreign language classes.

"I haven't been able to do these things for eight years and now I don't even know where to start," he said in a blog post.

Neuralink obtained the green light from the US Food and Drug Administration (FDA) in May 2023.

Its implant, the size of a coin, has already been placed in the brain of a monkey, which was then able to play a video game without physical controls.

In addition to the medical ambitions shared by numerous laboratories and 'start-ups', Elon Musk intends to offer his implant to everyone, in order to communicate better with computers and contain, according to the billionaire, the "risk to civilization" represented by "artificial intelligence".

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