While we don’t yet understand our brains in great detail, we do get the broad strokes. The brain uses a combination of electrical and chemical signals to “compute,” and repetitive thoughts equate to repeating electrical brain patterns. By feeding test subjects controlled stimuli and recording the subsequent patterns, we can reverse the process in the future.
Even if we don’t know what the subject is doing, when we see a familiar pattern, we can infer they’re looking at, hearing, seeing, or even thinking the same thing they were in the original experiment.
The University of Malta researchers, for example, observed the electrical patterns made by subjects’ brains when they looked at flickering boxes on a screen. As the flickering’s frequency varied, so too did each brain’s electrical patterns.
The group recorded the various brain patterns, assigned each frequency an action (play/pause, fast forward, volume), and coded the software to take certain actions when particular patterns were detected. Voilà: mind-controlled Spotify.
Similar principles have elsewhere been used to reconstruct images viewed by an individual by reading their neural signals alone. And reportedly, electronics giant Samsung is (very) preliminarily investigating mind-controlled smartphones as the next step beyond touch, gesture, and eye-controlled interfaces.