[EEBio]

It’s intentional and requires quite a lot of focus.

The original paper [0] mentions electrodes are placed over Broca’s area (speech production, translates words to mouth movements) and motor area (adjusts the mouth movements). It’s attempted speech, not thoughts.

There is a lot of fear in mainstream media and populace of devices decoding thoughts, but that is a significantly harder problem, at this moment on the level of sci-fi of Civilisation Type II on Kardashev scale. There is a reason why the electrodes are not over Wernicke’s area instead (language comprehension and production).

0: https://doi.org/10.1038/s41586-023-06377-x