Science · 7 min read
The technology behind brain-computer interfaces
Reading intention is now possible. Reading thought is not.
Three ways in
Electrodes placed on the scalp, on the surface of the cortex, or inside the tissue itself. Signal quality improves at every step inward, and so does surgical risk.
1000s
Electrode channels on current research arrays
What the signal actually contains
Motor intention decodes well because it is spatially organised and repeatable. Language decoding has advanced quickly for attempted speech, and remains far weaker for inner monologue.
Longevity is the quiet problem
Implants provoke scar tissue that degrades recordings over months to years. Flexible substrates and thinner films are the main line of attack.
